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Maastrichtian marine reptiles of the Mediterranean Tethys: A palaeobiogeographical approach
Abstract
A global comparison of coeval Maastrichtian marine reptiles (squamates, plesiosaurs, chelonians ana crocodyliformes) of Europe, New Jersey, northwestern Africa and Middle-East has been performed. More than twenty outcrops and fifty species (half of them being mosasaurids) have been recorded. PEA and Cluster Analysis have been performed using part of this database and have revealed that marine reptile faunas (especially the mosasaurid ones) from the Mediterranean Tethys are clearly segregated into two different palaeobiogeographical provinces: 1) The northern Tethys margin province (New Jersey and Europe), located around palaeolatitudes 30-40°N and developping into warm-temperate environments, is dominated by mosasaurid squamates and chelonioid chelonians; it is characterized by the mosasaurid association of Mosasaurus hoffmanni and Prognathodon sectorius. 2) The southern Tethys margin province ( Brazil and the Arabo-African domain), located between palaeolatitudes 20°N-20°S and developping into intertropical environments, is dominated by mosasaurid squamates and bothremydid chelonians; it is characterized by the mosasaurid association of Globidens phosphaticus as well as by Halisaurus arambourgi and Platecarpus (?) ptychodon (Arabo-African domain). These faunal differences are interpreted as revealing palaeoecological preferences probably linked to differences in palaeolatitudinal gradients and/or to palaeocurrents. On a palaeoecological point on view and concerning mosasaurids, the mosasaurines (Prognathodon, Mosasaurus, Globidens and Carinodens) prevail on both margins but with different species. The ichthyophageous plioplatecarpines Plioplatecarpus (Northern margin) and Platecarpus (?) ptychodon (Southern margin) characterise respectively each margin. The halisaurine Halisaurus is present on both margins but with different species. Of importance, the tylosaurines remain currently unknown on the southern Tethys margin and are restricted to higher palaeolatitudes. Chelonians (bothremydids and chelonioids) are respective of each margin, which probably indicates lower dispersal capabilities compared to mosasaurids. The relative scarcity of plesiosaurs and crocodyliformes could be linked to different ecological preferences. The noteworthy crocodyliforme diversity increase in the Palaeogene is probably linked to mosasaurid extinction during the biological crisis of the K/Pg boundary.
... Marine reptile fossils are frequently reported from Mesozoic strata of the Arabian Platform (Polcyn and Eitan, 1999;Bardet et al., 2000Bardet et al., , 2008Bardet, 2012). Although some Triassic and Jurassic remains have been reported, such as those from the Triassic Makhtesh Ramon, in Negev , and Jilh Formation, in central Saudi Arabia (Vickers-Rich et al., 1999;Kear et al., 2010), as well as from the Jurassic Hanifa Limestones near Jizan, southwestern Saudi Arabia (Madden et al., 1995), most records are Late Cretaceous in age. ...
... Although some Triassic and Jurassic remains have been reported, such as those from the Triassic Makhtesh Ramon, in Negev , and Jilh Formation, in central Saudi Arabia (Vickers-Rich et al., 1999;Kear et al., 2010), as well as from the Jurassic Hanifa Limestones near Jizan, southwestern Saudi Arabia (Madden et al., 1995), most records are Late Cretaceous in age. These include mainly squamates (mosasaurids, pachyvaranids, pachyophiids, ophiodomorphs), but also elasmosaurid and polycotylid plesiosaurs, bothremydid and chelonioid turtles, and thunnosaurian ichthyosaurs (e.g., Polcyn and Eitan, 1999;Bardet et al., 2000;Tong et al., 2006;Bardet et al., 2008;Kear et al., 2008;Bardet, 2012;Fischer et al., 2013;Rabinovich et al., 2015;Bardet et al., 2021). ...
... Lastly, an isolated tooth from the Maastrichtian Rutbah Formation of Iraq was assigned to Plesiosaurus mauritanicus (Arambourg et al., 1959), but later referred to Elasmosauridae indet. (Bardet, 2012). ...
Despite its relatively limited vertebrate fossil record, Syria currently records the largest number of documented Mesozoic marine reptile occurrences among the Middle Eastern countries. In particular, the phosphatic deposits of the Palmyrides mountain chain have yielded fossils of aquatic squamates, bothremydid and chelonioid marine turtles, as well as elasmosaurid plesiosaurs. Nevertheless, new discoveries have not been reported for the last two decades. Here, we describe the partial skeleton of an elasmosaurid plesiosaur from Syria, which comprises the middle and posterior cervical series, together with articulated pectoral, dorsal and anterior caudal parts of the vertebral column, with associated rib fragments. The fossil was excavated from Coniacian-Santonian phosphatic deposits of the Al Sawaneh el Charquieh mines, in the central part of the southwestern Palmyrides, about 200 km northeast of Damascus. The specimen can be assigned to Elasmosauridae based on the cervical centra morphology and, although incomplete, is significant because it not only represents likely the oldest, but also the currently most complete plesiosaur skeleton recovered from the Middle East.
... The mosasaurs (Mosasauridae) are an extinct group of marine reptiles that became abundant and diverse in the Upper Cretaceous [1]. Early work on mosasaurs focused heavily on Europe and North America [2][3][4][5][6][7], where paleontology first began as a science. Later on, they were also documented in South America and Antarctica [8][9][10][11][12][13][14][15][16][17][18]. ...
... Discoveries over the past half century have shown the widespread presence of Prognathodon in the subtropics of Africa and the Middle East, with Prognathodon now known in Egypt, Morocco, Israel, Congo, and Angola [6,24,29,90]. The discovery of the present Prognathodon specimens from Egypt increases our knowledge of the diversity and distribution of the Maastrichtian mosasaurs in Egypt and North Africa, and emphasizes the endemism of mosasaur faunas (Figure 9). ...
... saturator [27,93]; 7, Cabinda basin, Angola, Prognathodon sp., Prognathodon cf. currii [6]. Map redrawn after map by Ron Blakey. ...
Mosasaurs were diverse in the Upper Cretaceous in Africa, but relatively little is known about the mosasaur fauna of Egypt. Here, associated teeth and postcranial skeletal elements are reported for a mosasaur from the Maastrichtian Dakhla Shale of the Dakhla Oasis. The specimen includes tooth crowns, cervical, dorsal, and caudal vertebrae, and ribs. Teeth and bones exhibit features allowing referral to Prognathodontini. The teeth are relatively straight and blunt, suggesting affinities with Prognathodon overtoni or P. currii. Prognathodontins were important predators in the Maastrichtian of Africa, previously being recorded in Morocco, Congo, and Angola.
... In this study, we take an unprecedented regional and global approach to quantifying marine reptile disparity. The selection of geographic regions in this study reflects four of the most wellknown and well-sampled assemblages of mosasaurids and enables the investigation and interpretation of local and global drivers of marine reptile ecomorphological variation: the WIS; Northern Tethys Province (NTP); Southern Tethys Province (STP; [26]) and Weddellian Province (consisting of Southeast Oceania, the Antarctic peninsula and Patagonia; WED). Disparity was geographic regions during these time periods was also calculated. ...
... The drivers of ecomorphological differences we observe should not necessarily be regarded as global; a telling example is the provincial disparity patterns during the Maastrichtian (figure 3b-e), which may be associated with the magnitude of the environmental changes resulting from the sea-level regressions [6]. Indeed, the epicontinental WIS greatly changed in extent and shape during the Maastrichtian [45,46], and this region records the steepest decrease in α-disparity, while deeper basins such as Northern and STPs were seemingly less affected [8,13,26,47]. In this context, focussing on the Disparity estimates were generated using the SoV metric (1000 bootstrap replications); significant differences were recovered between all sequential time bins for global and provincial datasets using pairwise Wilcoxon testing (see also electronic supplementary material, tables S1 and S3). ...
... The retention of disparate ecomorphologies of STP mosasaurids through the Maastrichtian drive peak in provincial differentiation (table 2). The predominantly bimodal landscape of mosasaurids in the late Maastrichtian (figure 2e) suggests that, while a variety of niches were still being occupied by low densities of disparate mosasaurids, numerous Northern and Southern Tethys mosasaurids essentially exhibited 'megapredatory' or 'grasping' functional adaptations (figure 2; also [7,8,13,26]). Becoming increasingly apparent is the importance of the STP (including Afro-Arabia, Morocco, Niger-Nigeria, Angola and eastern Brazil) in driving the late Maastrichtian marine reptile diversity and disparity [26]. Understanding patterns such as these are vital for the accurate interpretation of faunal dynamics and functional variation before and after extinction events. ...
Mosasaurid squamates were the dominant amniote predators in marine ecosystems during most of the Late Cretaceous. Here, we use a suite of biomechanically rooted, functionally descriptive ratios in a framework adapted from population ecology to investigate how the morphofunctional disparity of mosasaurids evolved prior to the Cretaceous–Palaeogene (K/Pg) mass extinction. Our results suggest that taxonomic turnover in mosasaurid community composition from Campanian to Maastrichtian is reflected by a notable global increase in morphofunctional disparity, especially driving the North American record. Ecomorphospace occupation becomes polarized during the Late Maastrichtian, with morphofunctional disparity plateauing in the Southern Hemisphere and decreasing in the Northern Hemisphere. We show that these changes are not strongly associated with mosasaurid size, but rather with the functional capacities of their skulls. Our novel approach indicates that mosasaurid morphofunctional disparity was in decline in multiple provincial communities before the K/Pg mass extinction, highlighting region-specific patterns of disparity evolution and the importance of assessing vertebrate extinctions both globally and locally. Ecomorphological differentiation in mosasaurid communities, coupled with declines in other formerly abundant marine reptile groups, indicates widespread restructuring of higher trophic levels in marine food webs was well underway when the K/Pg mass extinction took place.
... Further synapomorphies of Mosasaurus featured in the Moroccan specimens include: (1) asymmetrical labial and lingual surfaces (lingual inflated); (2) flattened labial surface; (3) convex lingual surface; (4) two prominent carinae; (5) light serrations along anterior and posterior carina; (6) labiolingual tooth curvature (Russell, 1967;Lingham-Soliar, 1995;Bardet et al., 2004). from ecological preferences and/or paleocurrents (Nicholls and Russell, 1990;Bardet, 2012;Bardet et al., 2015). ...
... The Northern Margin (paleolatitudes 30-40°N) is characterized by Mosasaurus hoffmannii, Tylosaurus (Hainosaurus) bernardi, and Plioplatecarpus marshi, while the Southern Margin (20°S-20°N) is known for abundant remains from Prognathodon sp. (Leiodon anceps), Eremiasaurus heterodontus, Gavialimimus alamghribensis, and Globidens phosphaticus(Bardet and Tunoğlu, 2002;Bardet, 2012).The Oulad Abdoun Basin is a component of the Southern Tethys Margin and displays close paleobiogeographical affinity with Brazil and the Arabo-African Platform consisting of Angola, Egypt, Israel, Jordan, and Syria(Bardet, 2012). When comparing the Moroccan assemblage with mosasaurids from the Maastricht Formation (the Netherlands; Northern Tethys Margin),Bardet et al. (2015) notes that comparable ecological niches were filled by regionally unique, though morphologically convergent species. ...
... The Northern Margin (paleolatitudes 30-40°N) is characterized by Mosasaurus hoffmannii, Tylosaurus (Hainosaurus) bernardi, and Plioplatecarpus marshi, while the Southern Margin (20°S-20°N) is known for abundant remains from Prognathodon sp. (Leiodon anceps), Eremiasaurus heterodontus, Gavialimimus alamghribensis, and Globidens phosphaticus(Bardet and Tunoğlu, 2002;Bardet, 2012).The Oulad Abdoun Basin is a component of the Southern Tethys Margin and displays close paleobiogeographical affinity with Brazil and the Arabo-African Platform consisting of Angola, Egypt, Israel, Jordan, and Syria(Bardet, 2012). When comparing the Moroccan assemblage with mosasaurids from the Maastricht Formation (the Netherlands; Northern Tethys Margin),Bardet et al. (2015) notes that comparable ecological niches were filled by regionally unique, though morphologically convergent species. ...
Marginal tooth crowns from the hypercarnivorous marine reptile Mosasaurus hoffmannii Mantell, 1829 are reported for the first time from the Late Cretaceous (Maastrichtian) phosphates of Morocco. Fossilized remains of this species are previously known from Campanian and Maastrichtian outcrops in Europe, North America, and western Asia at a paleolatitudinal belt of 30-45°N. New fossil material originates from the Upper Couche III layer of the Oulad Abdoun Basin, south of Oued Zem, Morocco. The discovery of M. hoffmannii in Morocco extends its paleobiogeographic range south to 25°N and into the southern margin of the Mediterranean Tethys.
... A different issue exists for Maastrichtian Malian remains described from the Ménaka Formation (Hill et al., 2008;O'Leary et al., 2019). They come from the Iullemmeden Basin where numerous mosasaurs have been described from Niger and Nigeria (Bardet, 2012;Lingham-Soliar, 1998, 1991. In Mali, the facies of the sediments in which the fossils were found, a phosphate conglomerate, suggests a shallow marine to brackish environment (Hill et al., 2008;O'Leary et al., 2019). ...
... Such segregation also exists in Moroccan Late Cretaceous-Paleogene basins: in the Ganntour and Oulad Abdoun Basins, the Maastrichtian layers provided numerous mosasaurs and plesiosaurs remains, but few crocodyliform fossils, as confirmed by the crocodyliform/mosasaurid teeth ratio from the Oulad Abdoun Basin (about 1/1000) (Jouve et al., 2008a). A crocodyliform scarcity is also observed in Syria and Jordan phosphatic basins (Bardet and Pereda Suberbiola, 2002;Bardet, 2012). The same is true for the only specimen, Sokotosuchus ianwilsoni from the Maastrichtian in Nigeria, which is also the only known Maastrichtian Nigerian crocodyliform. ...
... A clear geographical segregation of longirostrine crocodyliforms was set up during the Maastrichtian-Paleocene period with two paleogeographical bioprovinces: the Northern Tethys province corresponding to former Laurasia (North America, Europe, and Asia), with several gavialoids, and only two tethysuchian species, and the southern Tethys margin province (South America, Africa, and Indian continent), corresponding to former Gondwana, with numerous tethysuchians, and only two gavialoids (Hastings et al., 2014;Hill et al., 2008;Jouve, 2004;Jouve et al., 2008aJouve et al., ,b, 2021 Jouve and Jalil, 2020) ( Fig. 3; Appendix 1 of Supplementary data). The same geographical segregation with north and south Tethys paleobioprovinces is observed in other marine reptiles during the Maastrichtian, and is interpreted as possibly related to differences in paleoecological preferences linked to differences in paleolatitudinal gradients and/or paleocurrents (Bardet, 2012). ...
The evolution of the crocodyliforms through the K-Pg crisis has often been evaluated, but each time, the crocodyliforms were considered as forming a homogeneous group. I considered here, the evolution of two longirostrine taxa from the Campanian to the Thanetian: tethysuchians and gavialoids. The gavialoids are almost restricted to Laurasian continents, where tethysuchians form most of the Gondwanan fauna. This segregation can be compared with climatic distribution: tethysuchians are restricted to hot climatic areas, where gavialoids are restricted to a northern, warm temperate climatic belt from where tethysuchians were almost excluded. This suggests that gavialoids were more tolerant of cooler climates than tethysuchians. The tethysuchians could have been excluded from the European continent by the existence of a cool European oceanic current, whilst on the contrary, the presence of a proto-gulfstream along north-east American coast could have allowed the presence of some tethysuchians in marine realm in this area. Both gavialoids and tethysuchians strongly diversified after the K-Pg crisis, particularly on Gondwanan continents, and mostly with tethysuchian species. Most of these tethysuchians were non-marine during the Maastrichtian, and the number of marine species strongly increases after the K-Pg crisis, whilst the number of non-marine ones remains nearly constant. This rise of marine diversity compared to non-marine forms is congruent with previous hypotheses suggesting that the crocodyliforms did not suffer from the K-Pg crisis, but on the contrary, benefited from the extinction of large marine reptiles to diversify after the crisis mainly in this environment. So, if the history of the crocodyliforms on the whole is important, the evolution of each group should be considered separately, as their evolution could be influenced by regional environmental conditions and factors.
... Squamata (Oppel, 1811) Mosasauridae (Gervais, 1852) Halisaurinae Bardet andPereda Suberbiola, 2005 in (Bardet et al., 2005b) Premaxillae. The anterior part of the premaxilla (Figs. 3, 4A) is proportionately short and broad to a degree not seen in other mosasaurids except Tethysaurus , being about twice as broad as long. ...
... In addition to contributing to our understanding of diversity and disparity, mosasaurid faunas from the Maastrichtian of Morocco document the existence of a distinct fauna found in the southern Tethys Margin Province, including the Arabo-African Platform and Brazil. The fauna of this province differs from those known elsewhere at the time such as the northwest Pacific of California, the southwest Pacific of New Zealand, and especially the Northern Tethys Margin Province of New Jersey and Europe (Bardet, 2012;Cappetta et al., 2014;Bardet et al., 2015). The faunas can be segregated into these two provinces (as defined by Bardet, 2012), respectively developed around palaeolatitudes 20°N-20°S into intertropical environments versus palaeolatitudes 30-40°N into warm-temperate environments. ...
... The fauna of this province differs from those known elsewhere at the time such as the northwest Pacific of California, the southwest Pacific of New Zealand, and especially the Northern Tethys Margin Province of New Jersey and Europe (Bardet, 2012;Cappetta et al., 2014;Bardet et al., 2015). The faunas can be segregated into these two provinces (as defined by Bardet, 2012), respectively developed around palaeolatitudes 20°N-20°S into intertropical environments versus palaeolatitudes 30-40°N into warm-temperate environments. The precise reasons for these differences remain unknown, but these patterns probably reveal palaeoecological preferences linked to differences in palaeolatitudinal gradients and/or to palaeocurrents (Bardet, 2012). ...
Mosasaurids (Mosasauridae) were specialized marine lizards that evolved and radiated in the Late Cretaceous. Their diversity peaked in the Maastrichtian, with the most diverse faunas known from Morocco. Here we describe a new species of mosasaurid from this fauna. Pluridens serpentis sp. nov. is described based on two complete skulls and referred jaws. It is referred to Pluridens based on the elongate and robust jaws, small teeth, and specialized tooth implantation. Pluridens is referred to Halisaurinae based on the posteriorly expanded premaxilla, long premaxilla-maxilla suture, broad premaxillary facet on the maxilla, closed otic notch, and small, striated, hooked teeth. The orbits are reduced relative to other halisaurines while the snout is robust and flat with a broad, rounded tip. The jaws bear numerous small, hooked, snake-like teeth. Skulls imply lengths of 5-6 meters; referred material suggests lengths of ≥10 meters. Pluridens’ specialized morphology – especially the contrasting large size and small teeth - suggests a distinct feeding strategy. Small orbits imply that P. serpentis relied on nonvisual cues including touch and chemoreception during foraging, as in modern marine snakes. Numerous neurovascular foramina on the premaxillae are consistent with this idea. The small teeth suggest proportionately small prey. The dentary becomes massive and robust in the largest individuals, suggesting sexual selection and perhaps sexual dimorphism, with the mandibles possibly functioning for combat as in modern beaked whales and lizards. The new mosasaur emphasizes how Maastrichtian mosasaurids were characterized by high species richness, functional diversity of niches occupied, and a certain degree of endemism, i.e. geographic specialization. and continued diversifying until the end of the Cretaceous, just prior to the K-Pg extinction.
... The species is also known from several other well-preserved specimens derived from the type stratum/locality (Bardet et al., 2005a;Polcyn et al., 2012), and very abundant isolated teeth from the Maastrichtian series in the Gantour Basin . Although abundant, H. arambourgi was not reported by Arambourg (1952), and is otherwise identified from the Maastrichtian of the Southern Tethys Margin of Syria, Jordan, Israel and Egypt (see details in Bardet, 2012). ...
... The unique and astonishing morphology of P. (?) ptychodon is actually very different from that of Platecarpus, and the species might belong to a new genus (Polcyn et al., work in progress) (Fig. 2B). Its highly diagnostic teeth have been reported from the Maastrichtian Southern Tethys margin of Syria, Jordan, Israel and Angola (see details in Bardet, 2012;Mateus et al., 2012). ...
... obs.); and some isolated teeth restricted to the Upper Maastrichtian (levels C3 and C2) in the Gantour Basin . It is also possibly identified from isolated teeth in the Maastrichtian of Brazil and Egypt (see details in Bardet, 2012). ...
... Based on the above-noted features, those parts of the skeleton under consideration have been designated elasmosaurid. Notably, similar finds of undetermined elasmosaurids have been found in Syria, Jordan, Iran, Egypt (Werner & Bardet, 1996;Bardet & Pereda Suberbiola, 2002;Bardet, 2012) and Morocco (Vincent et al., 2013). Although this is the first time that several elements supposedly of the same individual have been found in a clear context in the Menuha Formation, it is not unexpected that such finds would have been deposited in the Negev. ...
... Powell & Moh'd, 2011;Knutsen et al., 2012;O'Gorman, 2012;Vincent, 2012;Sachs et al., 2013). It is in this scholarly vein that we attempt here to explicate the newly excavated specimen from the Santonian deposit described above; its environment and its faunal context within the confines of the Mediterranean Tethys, and more specifically within the upwelling belt of the southern Tethys Sea (Bardet, 2012). , 1954;Bosworth et al., 1999), would the upwelled nu-trient-laden waters be able to penetrate the innermost south Tethys shelves, putting an end to the carbonate platform by excess of nutrients (e.g., Kinsey and Davies, 1979;Hallock and Schlager, 1986) and initiating an unusual sedimentary regime that produces the classic upwelling triad of organic-rich, silica-rich, and phosphate-rich sediments.' ...
... Most of the marine reptile remains from the southern Mediter-ranean Tethys are assigned to later periods. They are especially found in the Maastrichtian phosphatic belt (Bardet, 2012). However, as Bardet (2012, 585) has noted: 'Plesiosaurs remain too scarce so that no clear pattern of distribution can be derived from them.' Zarafasaura oceanis and body elements of elasmosaurids from the latest Cretaceous of Morocco, which may be of the same species (Vincent et al., 2013), provide new information about the palaeobiodiversity and palaeobiogeographical distribution of Maastrichtian plesiosaurs (Vincent et al., 2011). ...
A late Cretaceous elasmosaurid of the Tethys Sea margins (southern Negev, Israel), and its palaeogeographic reconstruction. Abstract Recent research on the late Cretaceous (Santonian), Menuha Formation of the southern Negev, Israel, has revealed several unconformities in its exposures, spatial changes in its lithofacies, agglomerations of its carbonate concretions and nodules at a variety of localities. At Menuha Ridge Site 20, portions of a new elasmosaurid skeleton were found within deposits of laminated bio-micritic muddy limestone with thin phosphatic layers. The sediments are rich in microfossils – foraminifera and ostracods preserved in the carbonate mud. Planktic foraminifera species (e.g. Dicarinella asymetrica, D. concavata, Sigalia decoratissima carpatica) appear as well as species indicative of opportunistic life strategies typical of a forming upwelling system in the region. Marine ostracods (e.g. Brachycythere angulata, Cythereis rosenfeldi evoluta) and many echinoid spines suggest an open marine environment. Using a multidisciplinary approach, we offer here a reconstruction of the micro-regional palaeogeog-raphy along a segment of the ancient shoreline of the Tethys Sea during the Santonian, and explain the environmental conditions under which the various fauna lived. This new elasmosaurid is examined in light of the above and compared with evidence from the adjacent areas along the margins of the southern Tethys Sea.
... The species is also known from several other well-preserved specimens derived from the type stratum/locality (Bardet et al., 2005a;Polcyn et al., 2012), and very abundant isolated teeth from the Maastrichtian series in the Gantour Basin . Although abundant, H. arambourgi was not reported by Arambourg (1952), and is otherwise identified from the Maastrichtian of the Southern Tethys Margin of Syria, Jordan, Israel and Egypt (see details in Bardet, 2012). ...
... The unique and astonishing morphology of P. (?) ptychodon is actually very different from that of Platecarpus, and the species might belong to a new genus (Polcyn et al., work in progress) (Fig. 2B). Its highly diagnostic teeth have been reported from the Maastrichtian Southern Tethys margin of Syria, Jordan, Israel and Angola (see details in Bardet, 2012;Mateus et al., 2012). ...
... obs.); and some isolated teeth restricted to the Upper Maastrichtian (levels C3 and C2) in the Gantour Basin . It is also possibly identified from isolated teeth in the Maastrichtian of Brazil and Egypt (see details in Bardet, 2012). ...
Mosasaurid squamates are the most numerically abundant, and taxonomically/ecologically diverse clade of marine amniotes represented in the Maastrichtian Phosphates of Morocco. With few exceptions, they are faunally typical of the Southern Mediterranean Tethys Margin (around palaeolatitude 25°N) and range from the base to the top of the stage. The Moroccan assemblages include at least 7 genera and 10 species representing a broad spectrum of sizes and morphologies that illustrate several ecological trends. Noteworthy is the predominance of Mosasaurinae which are widespread in contemporaneous outcrops worldwide and constitute 80% and 70% of the total genus/species number respectively. In contrast, Halisauromorpha and Russellosaurina (plioplatecarpines) are scarce and tylosaurines are presently unknown. All of the Moroccan mosasaurids exhibit characteristic tooth morphologies and can be placed into resource partitioning morphoguilds indicative of adaptations for piercing, crushing or cutting. Medium to large predators are found to distribute along the ‘Crush’-‘Cut’ axis of the morphoguild projection, and a new ‘Crush-Cut’ guild, previously unrecognised amongst Mesozoic marine amniotes, accommodates several Prognathodon species. Also of importance is the lack of mosasaurids along the ‘Pierce’-‘Crush’ axis, potentially inferring that these ecological niches were occupied by other marine vertebrates such as selachians and plesiosaurians. In addition, the relative abundance of mosasaurids throughout the Maastrichtian series of the Gantour Basin evidences direct ecological competition or predation phenomena.
... However, if we consider these Cretaceous-Palaeocene Pan-Chelonioidea in details, their palaeobiogeographical distribution appears rather limited, most genera being endemic, unlike their modern relatives that have a cosmopolitan distribution (Hirayama, 1997;Hirayama and Tong, 2003). This suggests that their dispersal was probably limited by biological or ecological constraints (Bardet, 2012). ...
... Mosasaurus, Tylosaurus, Prognathodon, etc.). However, in some specific cases, it appears that their distribution could have been influenced by latitudinal gradients, as demonstrated for the faunas from the Western Interior Seaway of North America (Nicholls and Russell, 1990), the Northern and Southern margins of the Mediterranean Tethys (Bardet, 2012) and the Weddelian Province (Martin and Fernández, 2007); this suggests that their biological characteristics could be responsible for and have influenced their ecological preferences. ...
... This is for example the case for Cretaceous ichthyosaurs, plesiosaurs and chelonians (Hirayama and Tong, 2003;Vincent et al., 2011;Fischer et al., 2014). Others, like mosasaurs (see Bardet, 2012), though exhibiting a remarkably global distribution, show at specific level parceling patterns likely linked to palaeolatitudinal gradients, for example in the Western Interior Seaway (Nicholls and Russell, 1990) and in the Mediterranean Tethys (Bardet, 2012), where the faunas differ from North to South. Finally, some groups, such as placodonts during the Triassic, pleurosaurid rhynchocephalians and basal Testudines during the Late Jurassic, as well as ophidiomorph squamates during the early Late Cretaceous, appear endemic to the Western Tethys. ...
During the Mesozoic, various groups of reptiles underwent a spectacular return to an aquatic life, colonizing most marine environments. They were highly diversified both systematically and ecologically, and most were the largest top-predators of the marine ecosystems of their time. The main groups were Ichthyosauria, Sauropterygia, Thalattosauria, and several lineages of Testudinata, Crocodyliformes, Rhynchocephalia and Squamata. Here we show that the palaeobiogeographical distribution of these marine reptiles closely followed the break-up of the supercontinent Pangaea and that they globally used the main marine corridors created by this break-up to disperse. Most Mesozoic marine reptile clades exhibit a cosmopolitan, or at least pandemic, distribution very early in their evolutionary history. The acquisition of morphological adaptations to a fully aquatic life, combined to special thermophysiological characteristics, are probably responsible for these animals to become efficient long-distance open-marine cruisers. Generally, Early Triassic taxa were near-shore animals mainly linked to the Tethys or Panthalassa coastlines. By the end of the Triassic and during the Jurassic, the break-up of Pangaea resulted in the formation of large marine corridors connecting the Tethys to the North Atlantic and Pacific realms, a trend increasing on during the Cretaceous with the expansion of the Atlantic Ocean and the break-up of the southern Gondwana, allowing open-sea marine reptiles to spread out over large distances. However, if large faunal interchanges were possible at a global scale following a dispersal model, some provinces, such as the Mediterranean Tethys, were characterized by a peculiar faunal identity, illustrating an absence of migration with time despite the apparent lack of barriers. So, if Continental Drift enabled global circulations and faunal interchanges via dispersals among Mesozoic marine reptiles, others parameters, such as ecological and biological constraints, probably also played a role in the local endemic distribution of some of these marine groups, as they do today.
... cf. hoffmanni) (Jagt, 2005;Jagt et al., 2006;Bardet, 2012), this specimen probably originated either from the Argille di Viano Formation (early Palaeocene-middle Eocene, but containing reworked boulders coming from the Flysch di Monte Cassio Formation, late Campanian-late Maastrichtian) or from the Argille Varicolori di Cassio Formation (late Cenomanian-late Campanian). Both formations are constituted mainly by clays and breccias (Gasperi , 2005). ...
... anceps). However, a recently described species from Morocco, Eremiasaurus heterodontus LeBlanc, Caldwell, and Bardet, 2012, possesses teeth bearing a striking resemblance to those described by Arambourg (1952) (see also Bardet et al. [2010] and Bardet [2012], who attribute the most gracile tooth form of 'Liodon cf. anceps' to Eremiasaurus and the most robust one to a new unnamed species of Prognathodon); the only differences between these specimens of Liodon cf. ...
... The Italian data provide evidence for the presence of these forms in the central regions of Tethys where they had not been reported before, and the list of countries where remains of M. cf. hoffmanni are present can be extended to include Belgium, northwest Bulgaria, Denmark, France, northern Germany, northern Italy, The Netherlands, central Poland, and northern Turkey (Fig. 6) (Gaudry, 1892;Bardet and Tunoglu, 2002;Reich and Frenzel, 2002;Machalski et al., 2003;Lindgren and Jagt, 2005;Jagt et al., 2006;Tunoglu and Bardet, 2006;Bardet, 2012;this work). Possible remains of M. cf. ...
A review of the remains of mosasaurine mosasaurs from the upper Campanian–Maastrichtian of Italy is provided. The first discoveries of mosasaur material from Italy are represented by a series of isolated teeth from the Scaglia Rossa Formation north of Vittorio Veneto (late Campanian). These teeth show some similarities to Prognathodon, Liodon, and Eremiasaurus, but are not identical and probably represent a new taxon. A partial mosasaur skull found south of Reggio Emilia in 1886 is potentially a new species of Mosasaurus, although more material is needed to support this possibility. This specimen is temporarily referred to M. cf. hoffmanni. A second fragmentary mosasaur skull was accidentally discovered in 1892 north of Verona during the demolition of a school (inside one of the building stones). Based on its general morphology, size, and dentition, this second specimen can be considered as very closely related to M. hoffmanni, but its older age (early–middle Maastrichtian) suggests that it likely represents a new species of Mosasaurus. We refrain from erecting new taxonomic names for these specimens pending the discovery of new, more complete material upon which satisfactory diagnoses can be based. The paleobiogeographic distribution of Mosasaurus hoffmanni, M. cf. hoffmanni, M. beaugei, Liodon, and Prognathodon is reviewed briefly.
SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at http://www.tandfonline.com/UJVP.
... As far as marine reptiles are concerned and apart from some exceptions probably linked to their scarcity or restricted stratigraphical range, most taxa are present in the Ganntour and the Ouled Abdoun phosphatic basins of Morocco. This suggests that the ecological conditions in both basins were probably comparable and not so different as previously thought (Bardet, 2012). The fact that the Benguérir marine reptile taxa occur throughout the Maastrichtian phosphatic succession also confirms that the comparable marine reptile assemblage of the Ouled Abdoun Basin does not correspond to a mixture of faunas in relation with a condensation of some levels of the phosphatic series but to a real faunal association (Bardet, 2012). ...
... This suggests that the ecological conditions in both basins were probably comparable and not so different as previously thought (Bardet, 2012). The fact that the Benguérir marine reptile taxa occur throughout the Maastrichtian phosphatic succession also confirms that the comparable marine reptile assemblage of the Ouled Abdoun Basin does not correspond to a mixture of faunas in relation with a condensation of some levels of the phosphatic series but to a real faunal association (Bardet, 2012). ...
... More than half of the squamate association appears to be restricted to the southern Tethys margin. Among them are the pachyvaranid Pachyvaranus crassispondylus, found up to now only in the Maastrichtian of Syria and Morocco (Houssaye et al., 2011), and the mosasaurids Mosasaurus beaugei, "Platecarpus" ptychodon, Halisaurus arambourgi, Globidens phosphaticus, Prognathodon currii and possibly Prognathodon sp., all taxa found only in the Maastrichtian of the southern Tethys Margin (Bardet, 2012). These squamates could thus be useful tools to define this large palaeoprovince as they are quite different from those of the northern Tethys and otherwise remain unknown elsewhere. ...
The Maastrichtian of Benguérir (eastern part of the Ganntour Basin, Morocco) consists of about 20 meters of phosphates displaying an alternation of soft phosphate levels, marly horizons and hard phosphatic limestones. Isolated teeth of selachians, actinopterygians and marine reptiles are extremely numerous in these phosphatic deposits and have been used for both biostratigraphical, palaeodiversity and palaeoecological purposes.
Detailed field work allowed to establish an exhaustive list of the Benguérir marine vertebrate faunas with their biostratigraphical distribution through five main fossiliferous levels (L6 to L2) spanning all the Maastrichtian. Their importance for biochronological purposes and correlations with other Maastrichtian phosphate deposits worldwide appears noteworthy.
The selachians are currently represented by 60 species belonging to 32 genera and 7 orders. Among them, the genus Squalicorax is one of the most interesting concerning high-resolution biostratigraphy and correlations with other phosphate basins because of important rates of change noted between the 5 species recovered from base (e.g. occurrence of S. africanus) to top (e.g. strong representation of S. pristodontus) of the Maastrichtian. The marine reptiles include mainly mosasaurids but also scarcer plesiosaurs, chelonians and crocodylians, representing at least 14 taxa. The mosasaurid squamates are the most abundant and diversified with at least 8 species ranging all along the succession. The actinopterygians include mainly teleosts but also pycnodonts, also common in all levels and representing at least 7 taxa.
Selachians and reptiles show the same trends, in term of species richness per level, even if the reptiles are less informative due to a less diversified assemblage. For sharks, L6 and L2 show a high percentage of genera and species occurring only in the layer concerned. The evolution of diversity in actinopterygian fishes are less clear because of their low diversity. The use of dissimilarity indices and agglomerative method underscores two distinct associations: a lower one including the levels L6 and L5, and an upper one comprising the levels L4 to L2. These two associations allow to separate a lower and an upper Maastrichtian level and are important for correlations all around the southern and eastern margins of the Tethys. Another clear faunal turnover occurs between L3 and L2, because a high appearance rate in L2 (at least in sharks) suggesting an increase in prey abundance, as testified by the rapid increase of marine predator density.
Indeed, and through L6 to L2, a possible signal of an environmental damage affecting the predator community can be noted by faunal turnovers, even if no significant change in prey association was clearly detected.
From a palaeobiogeographical point of view, the faunal associations of Benguérir appear typical of the southern and eastern margins of the Tethys, with several typical species not occurring in the northern Tethys.
... Plioplatecarpinae form a very diverse mosasaurid clade represented by about ten genera (Fig. 10): Angolasaurus from the Turonian of Angola (Antunes, 1964;Mateus et al., 2012); Platecarpus from the Turonian-Maastrichtian of Brazil, USA, Europe (France, Spain) (Bardet et al., 1991(Bardet et al., , 2008Everhart, 2001;Bengtson and Lindgren, 2005;Konishi et al., 2010Konishi et al., , 2012Bardet, 2012b); Plesioplatecarpus from the Coniacian-Santonian of USA (Everhart, 2001;Bell et al., 2013); Ectenosaurus from the Santonian (possibly Coniacian-Campanian) of USA (Kiernan, 2002;Everhart, 2004;Bell et al., 2013); Selmasaurus from the Santonian-Campanian of USA (Wright and Shannon, 1988;Konishi, 2008); Latoplatecarpus from the Campanian of Canada ; Plioplatecarpus from the Campanian-Maastrichtian of North America (USA, Canada), Europe (Belgium, The Netherlands), Africa (Congo, Niger), and Argentina (Lingham-Soliar, 1991, 1994a, 1994bTokaryk, 1993;Holmes, 1996;Cuthbertson et al., 2007;Fern andez et al., 2008;Konishi andCaldwell, 2009, 2011); Gavialimimus almaghribensis from the Maastrichtian of North Africa (Morocco) and Middle-East (Syria, Jordan, Israel) (Bardet et al., 2000;Bardet and Pereda Suberbiola, 2002;Bardet, 2012b;Strong et al., 2020). The species "Platecarpus" somenensis from the Santonian-Campanian of France and Sweden (Th evenin, 1896;Persson, 1959) is now referred to an indeterminate plioplatecarpine (Konishi et al., 2010;. ...
... Plioplatecarpinae form a very diverse mosasaurid clade represented by about ten genera (Fig. 10): Angolasaurus from the Turonian of Angola (Antunes, 1964;Mateus et al., 2012); Platecarpus from the Turonian-Maastrichtian of Brazil, USA, Europe (France, Spain) (Bardet et al., 1991(Bardet et al., , 2008Everhart, 2001;Bengtson and Lindgren, 2005;Konishi et al., 2010Konishi et al., , 2012Bardet, 2012b); Plesioplatecarpus from the Coniacian-Santonian of USA (Everhart, 2001;Bell et al., 2013); Ectenosaurus from the Santonian (possibly Coniacian-Campanian) of USA (Kiernan, 2002;Everhart, 2004;Bell et al., 2013); Selmasaurus from the Santonian-Campanian of USA (Wright and Shannon, 1988;Konishi, 2008); Latoplatecarpus from the Campanian of Canada ; Plioplatecarpus from the Campanian-Maastrichtian of North America (USA, Canada), Europe (Belgium, The Netherlands), Africa (Congo, Niger), and Argentina (Lingham-Soliar, 1991, 1994a, 1994bTokaryk, 1993;Holmes, 1996;Cuthbertson et al., 2007;Fern andez et al., 2008;Konishi andCaldwell, 2009, 2011); Gavialimimus almaghribensis from the Maastrichtian of North Africa (Morocco) and Middle-East (Syria, Jordan, Israel) (Bardet et al., 2000;Bardet and Pereda Suberbiola, 2002;Bardet, 2012b;Strong et al., 2020). The species "Platecarpus" somenensis from the Santonian-Campanian of France and Sweden (Th evenin, 1896;Persson, 1959) is now referred to an indeterminate plioplatecarpine (Konishi et al., 2010;. ...
New mosasaurid remains (Squamata) were collected from various Santonian localities in the Sougraignearea (Aude Department, southern France). Cranial bones, some vertebrae, two scapulae and a phalanx areassigned to the plioplatecarpine Platecarpus cf. tympaniticus, while pelvic bones, two vertebrae and afemur (?) are referred to Tylosaurus sp. Tooth marks made by sharks, teleosts or mosasaurids areobserved on the mosasaurid vertebrae. These Santonian (86.3e83.6 Ma) Platecarpus occurrences, knownsince almost one century, are the oldest from Europe. This deposit also yielded some elasmobranch teeth,belonging to taxa such as Squalicorax kaupi, Cretoxyrhina mantelli, Cretolamna sp. and Polyacrodus bra-banticus. A review of plioplatecarpine palaeobiogeographical distribution through Late Cretaceous sug-gests that it follows that of other mosasaurid clades, reaching a worldwide distribution by Maastrichtiantime, probably favored by marine routes largely opened at this time
... Blocks of continental crust moving into the spreading area of the Tethys created a series of moving and fluctuating islands that altered population dynamics and geological features in their wake (Csiki-Sava et al., 2015). This unique region formed the basis of many unique faunas and was arguably the driving force behind many distinctive radiations (Bardet et al., 2008;Bardet, 2012;Csiki-Sava et al., 2015). ...
... And yet, dolichosaurs are not the only group that show a surprising amount of characteristic localized faunas. An interesting correlation exists between the multiple endemic populations of dolichosaurs and that of Late Cretaceous pan-chelonioids, certain Tethyan mosasaurs, and the latest Cretaceous plesiosaurs, who all-despite a suite of marine dispersal routes-showed a high degree of specific endemism, even though they were distributed worldwide in shallow marine environments (Hirayama, 1997;Vincent et al., 2011;Bardet, 2012;Kear et al., 2013;Bardet et al., 2014). It is possible that this is related to island biogeography, and that these populations were specialized to the particular ecology surrounding an island or island system. ...
Non-ophidian ophidiomorphs, colloquially referred to as ‘dolichosaurs,’ are small-bodied aquatic lizards that lived in shallow seaways, rivers, and reef environments during the Late Cretaceous. Preservational, geographic, and taphonomic biases in this group make trends in biodiversity difficult to assess. This is exemplified by the fact that the majority of the described species are monotypic and known only from single specimens, imparting very little information on morphological or spatial variation. Here we present a revision of the spatial and temporal distributions of non-ophidian ophidiomorph lizards (‘dolichosaurs’) from Cretaceous sediments worldwide. The fossil record of dolichosaurs begins in the Valanginian (Early Cretaceous). The late Early Cretaceous records are sparse but suggest a wide geographic distribution spanning the Tethys and Western Pacific. This is followed by a dense Cenomanian record from Tethyan and British deposits, and rarer specimens from North America. Though there is a substantial drop in the number of specimens recorded from the Turonian–Maastrichtian, these rare occurrences represent the largest geographical distribution of dolichosaurs: spanning Europe, North America, and South America before going extinct during the end-Cretaceous mass extinction. These occurrences indicate that ophidiomorphs most likely originated in the Jurassic Tethys and continued to radiate spatially and phylogenetically until the end of the Mesozoic, showing much more temporally and environmentally diverse patterns than previously indicated.
... The Maastrichtian record of Globidens is even more sparse, but occurrences of the genus have been recorded from Egypt (Zdansky, 1935), Israel (Raab, 1963), Syria (Bardet et al., 2000), Belgium (Lingham-Soliar, 1999), Jordan (Bardet & Pereda Suberbiola, 2002), Morocco (Arambourg, 1952;Bardet et al., 2005), Angola (Polcyn et al., 2010) and Brazil (see: Bardet, 2012). All of this material has been assigned to a single species, G. phosphaticus Bardet et al. (2005) and only one of these published occurrences is represented by more than isolated tooth crowns (Polcyn et al., 2010). ...
... Locality: The exact provenance for this specimen is unknown, but comparisons of the matrix and state of preservation of this material is consistent with other mosasaurine skeletons described from the Lower 'Couche III' of the Ganntour phosphate basin and the Upper 'Couche III' of the Oulad Abdoun basin, which are considered Lower and Upper Maastrichtian, respectively (Schulp et al., 2009;Bardet et al., 2015). More specifically, the grey phosphatic matrix from the field jackets (Supporting Information, Fig. S2) and the white colour and chalky texture of the bones indicate that this specimen was probably recovered from the Upper 'Couche III', possibly from the Oulad Abdoun Basin, south-east of Casablanca, Morocco (see: Bardet et al., 2005;Bardet, 2012). ...
Durophagous mosasaurs are rare members of Late Cretaceous marine faunal assemblages and new fossil discoveries can shed light on their anatomy, functional morphology and evolutionary history. Here we describe a new species in the durophagous genus Globidens from the Maastrichtian phosphate deposits of Morocco, based on a partial disarticulated skull and cervical vertebral series. This new species shares many anatomical similarities with the only other described Maastrichtian species, G. phosphaticus, but differs in several key features, including the absence of pronounced swellings and sulci on the crushing teeth and the absence of cervical zygosphenes and zygantra. Histological thin sections of a rib from the holotype show that this was not a juvenile individual and reveal osteosclerotic-like bone compactness for the first time in a paddle-bearing mosasaurine. We interpret the highly compact ribs, as well as several peculiarities of the temporal arcade and lower jaws, as adaptations to a diet of benthic, hard-bodied prey.
... In the Maastrichtian of the Middle East, the mosasaurid record includes G. phosphaticus from the Southern Tethys Margin of Syria, Jordan, and Israel (Bardet et al., 2005b(Bardet et al., , 2015Bardet, 2012). Globidens sp. ...
... Other mosasaurine records in Syria include M. cf. hoffmanni (Bardet et al., 2012) and one Mosasaurinae indet. (Bardet et al., 2000). ...
Herein, we present a revision of mosasauroid lizards (basal aigialosaurs + derived mosasaurids) from the Upper Cretaceous marine sediments associated with various Gondwanan landmasses. In stratigraphic terms, the Gondwanan fossil record of mosasaurs begins with basal mosasauroids from the carbonate platforms of the Middle East, in modern Israel. This record is followed by a dense Turonian record from Morocco and more rare specimens from the Turonian of Australia and Colombia. There is a substantial gap in the Coniacian and Santonian in Gondwana with only few known taxa, although the Campanian record from New Zealand is good (tylosaurines and mosasaurines), with additional rare specimens from Antarctica. Maastrichtian sediments from around the Gondwanan
world are richly populated by a high diversity and density of all major clades of mosasaurid lizards. The mosasaurine Clidastes is currently not recognized from any Gondwanan marine deposit. The geographic and temporal patterns of distribution shown here are crucial for understanding the evolution of aquatic squamates not only in Gondwana but also globally.
... These are Eonatator sternbergii (Wiman, 1920) Bardet and Pereda Suberbiola in Bardet et al., 2005a;Halisaurus platyspondylus Marsh, 1869; Halisaurus arambourgi Bardet and Pereda Suberbiola in Bardet et al., 2005a;and Phosphorosaurus ortliebi Dollo, 1889. A fifth species -Halisaurus walkeri (Lingham-Soliar, 1998) from the Maastrichtian of Nigercould be recognized as valid according to Lindgren and Siverson (2005) and Bardet (2012). Most recently, a new species, Eonatator coellensis, was described from Columbia on the basis of a mostly articulated skeleton (Páramo-Fonseca, 2013). ...
... In spite of the comparatively scarce record, their geographic distribution reveals that halisaurines were widely distributed, at least during the Maastrichtian. They have been documented from both paleogeographic provinces of the Mediterranean Tethys, from the Western Interior seaway, Gulf Coast and East Pacific of North America, from the Iullemmenden basin (Niger-Nigeria), and from the Kristianstad Basin in southern Sweden (Bardet, 2012;Lindgren and Siverson, 2005;Lindgren, 2007). A new halisaurine has been recently reported from the Lowest Maastrichtian of northern Japan (Konishi et al., 2013) extending their spatial distribution to the northwestern Pacific. ...
tHalisaurinae is a subfamily of enigmatic, small- to medium-sized mosasauroids, whichretain a mosaic of primitive and derived features. The first record of a South American Hal-isaurus with precise stratigraphic information includes a quadrate carrying a tympanic disctogether with twelve vertebrae, collected in the Late Maastrichtian of Jagüel Formationin northern Patagonia (Argentina). The preservation of a tympanic disc allows exploringand discussing the mechanisms of sound transmission in these mosasauroids. The loca-tion of the tympanic disc resembles that one formed by the extracolumella of aquaticturtles and at least one extant lizard. Based on morphological comparison of the middleear we discuss previous hypotheses on the modification of the tympanic middle ear systemof mosasauroids for underwater hearing, in a manner similar to that observed in aquaticturtles.
... These are Eonatator sternbergii (Wiman, 1920) Bardet and Pereda Suberbiola in Bardet et al., 2005a;Halisaurus platyspondylus Marsh, 1869; Halisaurus arambourgi Bardet and Pereda Suberbiola in Bardet et al., 2005a;and Phosphorosaurus ortliebi Dollo, 1889. A fifth species -Halisaurus walkeri (Lingham-Soliar, 1998) from the Maastrichtian of Nigercould be recognized as valid according to Lindgren and Siverson (2005) and Bardet (2012). Most recently, a new species, Eonatator coellensis, was described from Columbia on the basis of a mostly articulated skeleton (Páramo-Fonseca, 2013). ...
... In spite of the comparatively scarce record, their geographic distribution reveals that halisaurines were widely distributed, at least during the Maastrichtian. They have been documented from both paleogeographic provinces of the Mediterranean Tethys, from the Western Interior seaway, Gulf Coast and East Pacific of North America, from the Iullemmenden basin (Niger-Nigeria), and from the Kristianstad Basin in southern Sweden (Bardet, 2012;Lindgren and Siverson, 2005;Lindgren, 2007). A new halisaurine has been recently reported from the Lowest Maastrichtian of northern Japan (Konishi et al., 2013) extending their spatial distribution to the northwestern Pacific. ...
Halisaurinae is a subfamily of enigmatic, small- to medium-sized mosasauroids, which retain a mosaic of primitive and derived features. The first record of a South American Halisaurus with precise stratigraphic information includes a quadrate carrying a tympanic disc together with twelve vertebrae, collected in the Late Maastrichtian of Jagüel Formation in northern Patagonia (Argentina). The preservation of a tympanic disc allows exploring and discussing the mechanisms of sound transmission in these mosasauroids. The location of the tympanic disc resembles that one formed by the extracolumella of aquatic turtles and at least one extant lizard. Based on morphological comparison of the middle ear we discuss previous hypotheses on the modification of the tympanic middle ear system of mosasauroids for underwater hearing, in a manner similar to that observed in aquatic turtles.
... Marine sediments at Bentiaba, Angola, have produced one of the most diverse assemblages of marine amniotes known from the Cretaceous (Mateus et al., 2012; Fig. 1; Table 1), comparable to the type Maastricht fauna of the Netherlands and Belgium (Jagt, 2005) and the Maastrichtian beds of Morocco (Bardet, 2012). The Bentiaba assemblage is of particular importance because of the high richness of mosasaurs, a group of extinct marine lizards, and other top predators that have been interpreted as reflecting bottom-up selection pressure within a productive ocean ecosystem during the last 32 million years of Cretaceous time . ...
... Along passive margins, Calvert Cliffs, Maryland, preserves a rich cetacean fauna, but the accumulation is attritional over millions of years (Vogt & Eshelman, 1987;Gottfried et al., 1994). In Africa, the Cretaceous upwelling area along Morocco is the antitropical equivalent of that which occurred at the same time along the Bentiaba coast and it has produced a rich and varied marine fauna (Bardet et al., 2010;Bardet, 2012). However, upwelling in Morocco Netherlands Journal of Geosciences --Geologie en Mijnbouw produced phosphatic sediments and specimens are not concentrated as in the Bench 19 Fauna. ...
The Bench 19 Bonebed at Bentiaba, Angola, is a unique concentration of marine vertebrates preserving six species of mosasaurs in sediments best correlated by magnetostratigraphy to chron C32n.1n between 71.4 and 71.64 Ma. The bonebed formed at a paleolatitude near 24°S, with an Atlantic width at that latitude approximating 2700 km, roughly half that of the current width. The locality lies on an uncharacteristically narrow continental shelf near transform faults that controlled the coastal outline of Africa in the formation of the South Atlantic Ocean. Biostratigraphic change through the Bentiaba section indicates that the accumulation occurred in an ecological time dimension within the 240 ky bin delimited by chron 32n.1n. The fauna occurs in a 10 m sand unit in the Mocuio Formation with bones and partial skeletons concentrated in, but not limited to, the basal 1-2 m. The sediment entombing the fossils is an immature feldspathic sand shown by detrital zircon ages to be derived from nearby granitic shield rocks. Specimens do not appear to have a strong preferred orientation and they are not concentrated in a strand line. Stable oxygen isotope analysis of associated bivalve shells indicates a water temperature of 18.5°C. The bonebed is clearly mixed with scattered dinosaur and pterosaur elements in a marine assemblage. Gut contents, scavenging marks and associated shed shark teeth in the Bench 19 Fauna indicate biological association and attrition due to feeding activities. The ecological diversity of mosasaur species is shown by tooth and body-size disparity and by δ13C analysis of tooth enamel, which indicate a variety of foraging areas and dietary niches. The Bench 19 Fauna was formed in arid latitudes along a coastal desert similar to that of modern Namibia on a narrow, tectonically controlled continental shelf, in shallow waters below wave base. The area was used as a foraging ground for diverse species, including molluscivorus Globidens phosphaticus, small species expected near the coast, abundant Prognathodon kianda, which fed on other mosasaurs at Bench 19, and species that may have been transient and opportunistic feeders in the area.
... Paleogeographic reconstructions for the western Tethyan domain at the end of the Campanian indicate a fully oceanic environment for the deposition of the Argille Scagliose Complex (Fig. 11), as documented by the repeating sequences of pelagic and turbiditic deposits from which MGGC 21876 was collected. Therefore, unlike the well-known taxa from the Western Interior Basin of North America and from northwestern Europe, MGGC 21876 extends the mosasaur record outside shallow marine and epicontinental-sea environmental settings (Bernard et al., 2010;Bardet, 2012b;Houssaye et al., 2013;Polcyn et al., in press). ...
... Such a tooth is not known in any other mosasaur taxon known to date. M. hoffmanni, since the latter is not documented from the Campanian of Europe (Bardet, 2012b). The referral of the Italian specimen to M. hoffmanni, although not implausible, would extend the European record of that species prior to the Maastrichtian, an implication that we prefer not to endorse based on the limited diagnostic data observed in the Monte Ceti specimen. ...
A snout of a large-sized mosasaur from the Upper Cretaceous pelagic-turbiditic deposits of the Argille Scagliose Complex of Northern Italy is described. Nannofossil assemblages from the immediately overlying strata belong to the late but not latest Campanian calcareous nannofossil standard zone CC22, based on the presence of Uniplanarius trifidus and Eiffellithus eximius. The specimen includes a broken premaxilla, the anterior part of the maxillae and dentaries in articulation: preserved teeth show distinctive characters previously unreported in other mosasaurs. Although the marginal teeth show a posterior migration of the labial carina along the jaw length – diagnostic of derived mosasaurines – they are unusual in the combination of features, including anteriormost teeth with asteroid cross section followed by teeth with crowns twisted labioposteriorly from one-third to one-half of their height toward the apices. A comparison between the new specimen and Mosasaurus hoffmanni skulls suggests an estimated skull length comparable with some of the largest known mosasaurids. Consequently, the new specimen represents the largest mosasaur and the largest fossil reptile found in Italy to date. Several lines of dental evidence also support the interpretation of the Italian mosasaur as a macrophagous generalist predator. Paleogeographic reconstruction for the Argille Scagliose Complex as well as the occurrence of typical low- to mid-latitude nannofossils support a southern Tethyan margin affinity of the taxon.
... The MCMF is part of a larger Upper Cretaceous-Eocene carbonate and phosphate sequence that extends across northern Africa and into the Middle East 27 . Phosphatic deposits formed in areas of high primary productivity are known to preserve abundant vertebrate fossils, including remains of, for example, mosasaurs, plesiosaurs, sharks, bony fish, turtles and marine crocodylians 27,28 . With the notable exception of ref. 25, reports of Cretaceous vertebrates from the phosphatic deposits of Jordan have hitherto been based on a relatively limited material; however, the fossils indicate a diverse fauna similar in composition to that of Morocco [28][29][30][31] . ...
... Phosphatic deposits formed in areas of high primary productivity are known to preserve abundant vertebrate fossils, including remains of, for example, mosasaurs, plesiosaurs, sharks, bony fish, turtles and marine crocodylians 27,28 . With the notable exception of ref. 25, reports of Cretaceous vertebrates from the phosphatic deposits of Jordan have hitherto been based on a relatively limited material; however, the fossils indicate a diverse fauna similar in composition to that of Morocco [28][29][30][31] . On the basis of sequence stratigraphy 26 and microfaunal composition 32 , the oldest fossils from the MCMF are early to mid-Maastrichtian in age, although the age of the remaining Cretaceous part of the formation is unknown (including its precise age in the Harrana area and whether or not it reaches the Cretaceous/Paleogene boundary). ...
Mosasaurs are secondarily aquatic squamates that became the dominant marine reptiles in the Late Cretaceous about 98-66 million years ago. Although early members of the group possessed body shapes similar to extant monitor lizards, derived forms have traditionally been portrayed as long, sleek animals with broadened, yet ultimately tapering tails. Here we report an extraordinary mosasaur fossil from the Maastrichtian of Harrana in central Jordan, which preserves soft tissues, including high fidelity outlines of a caudal fluke and flippers. This specimen provides the first indisputable evidence that derived mosasaurs were propelled by hypocercal tail fins, a hypothesis that was previously based on comparative skeletal anatomy alone. Ecomorphological comparisons suggest that derived mosasaurs were similar to pelagic sharks in terms of swimming performance, a finding that significantly expands our understanding of the level of aquatic adaptation achieved by these seagoing lizards.
... Colonization of now-empty environments may have allowed cases of niche partitioning. Niche partitioning has been described in thalattosuchians (De Andrade et al. 2010), eusuchians (Hastings and Hellmund 2017), and marine Mesozoic squamates (Bardet 2012;Bardet et al. 2015). Such a pattern is also present in dyrosaurids. ...
Crocodylomorpha is a large and diverse clade with a long evolutionary history now restricted to modern crocodilians. Tethysuchia is a less-inclusive clade of semi-amphibious taxa that crossed two biological crises: the second Oceanic Anoxic Event (OAE 2) and the Cretaceous/Paleogene (K/Pg) crisis. Numerous studies have sought to find the driving factors explaining crocodylomorph evolution, producing contradictory conclusions. Studies of included groups may be useful. Here, we study factors driving tethysuchian evolution using phylogenetically informed statistical analyses. First, we tested the phylogenetic structure of tethysuchian extinction at the OAE 2 and K/Pg crises. We then used phylogenetic comparative methods to test the influence of intrinsic (body size, snout proportion) and extrinsic (temperature, paleolatitude) factors on the evolution of tethysuchian diversity at the OAE 2 and the K/Pg crises. Finally, we tested whether temperature influenced the evolution of body size. We conclude that (1) extinction was not random in regard to phylogeny for Tethysuchia at the OAE 2 and K/Pg crises; (2) while an important tethysuchian turnover follows OAE 2, the K/Pg crisis was followed by an explosion in diversity of tethysuchians, probably linked to the colonization of emptied ecological niches; (3) tethysuchians lived in warmer environments after the OAE 2 crisis, possibly because of both global warming and latitudinal distribution shifts; (4) there is a significant change of snout proportion after the OAE 2 and the K/Pg crises, likely caused by niche partitioning; and (5) there is a positive correlation between body size and temperature, possibly because of a longer growth season.
... Based on data acquired from thousands of isolated fossil teeth collected over many decades, Cappetta et al. (2014) provided a complete faunal list of Maastrichtian marine vertebrates in the eastern Gantour basin. Marine reptiles, including elasmosaurid plesiosaurs, mosasaurid species, and pachyvaranid squamates, and several selachian families such as Anacoracidae, Hypsobatidae, Pseudocoracidae, Sclerorhynchidae, and Rhombodontidae, abruptly disappeared during the K-Pg extinction event (Bardet, 2012;Cappetta, 1987;Cappetta et al., 2014;Lebrun, 2020). However, the fossilized remains of these marine reptiles and selachians in the eastern Gantour basin have been found to be abundant in the "C2" level, although their stratigraphic subdivisions and sampling positions have never been properly reported Noubhani and Cappetta, 1997). ...
The Late Cretaceous–early Paleogene interva is globally associated with transient to long-term changes in the stable carbon isotopic composition of marine carbonates δ13Ccarb). Based on biostratigraphic reconstruction, this critical period of Earth's history is thought to coincide with the deposition of world heritage Paleocene phosphate deposits (phosphorites) in northwestern Morocco. However, the detailed stratigraphy of the Gantour basin, one of the most important Moroccan phosphate deposits, has not yet been constrained. For instance, the former
“Montian” Stage has been used to tentatively approximate the Danian, whereas the succeeding Selandian Stage remains to be identified. Here, we develop a detailed organic carbon isotopic (δ13Corg) curve from phosphorus-rich horizons of the western Gantour sedimentary sequence in an attempt to constrain their stratigraphic placement and depositional age model. Upsection, these strata host long-term negative and positive δ13Corg trends that tend to correlate with global δ13Ccarb records of the Cretaceous–Paleogene and mid-Thanetian transitional boundaries. The data support the presence of Danian and Selandian rocks in the Gantour basin, which are succeeded by strata containing characteristic signatures of the well-known Cenozoic δ13C maximum at 58–57.5 Ma (the Paleocene Carbon Isotope Maximum). Our results shift the previously proposed Cretaceous–Paleogene transition in the Gantour basin further down into the older sediment C2M layer without interfering with recorded massive biological turnover in faunal diversity and abundance. Moreover, the refined stratigraphy suggests that the deposition of the Gantour phosphorites spanned ~8.5 Myr. Our results confirm the utility of δ13Corg chemostratigraphy for dating and correlating phosphate-bearing deposits of the Tethyan province. They have important implications for deciphering Paleocene phosphogenesis, the co-evolution of associated vertebrate groups, and for prospecting phosphorus-rich mineral deposits
... Enchodus, Dercetis, Apuliadercetis, Hastichthys [Goody, 1969;Chalifa, 1989;Breton et al., 1995;Taverne, 2006;Khalloufi et al., 2010;Friedman et al., 2015;Alvarado-Ortega y Díaz-Cruz, 2021;Díaz-Cruz et al., 2022]). Es muy probable que la relación entre grupos contemporáneos haya sido muy estrecha, al grado que incluso pudieron haberse desplazado en conjunto, tal como fue sugerido por Bardet (2012) y Bardet et al. (2015) quienes notaron este tipo de asociaciones entre osteíctios y reptiles marinos entre las regiones del norte y sur del Tetis. ...
En este trabajo se describe una nueva especie de enchodóntido del género †Saurorhamphusde estratos Aptianos-Albianos de la localidad de El Espinal en el Municipio de Ocozocoautla de Espinosa, Chiapas. Los ejemplares aquí estudiados presentan las características diagnósticas del género como son: un rostro alargado, articulación entre el cuadrado y mandíbula oculta, la porción ventral del preopérculo anteroposteriormente expandida, el borde posterior del opérculo forma una espina ypresencia de escudos dorsales. La nueva especie de †Saurorhamphusse denomina provisionalmente como †S. de El Espinal y es posible diferenciarla de sus congéneres con base en el número total de vértebras y por la presencia de caracteres morfológicos únicos como son una región postorbital reducida, la articulación cuadrado-mandíbula localizada al nivel de la órbita ocular, aleta dorsal hipertrofiada y posicionada en la mitad anterior del tronco y un par de aletas pélvicas pequeñas en posición abdominal.
El reporte de esta nueva especie de †Saurorhamphus en México extiende el rango de distribución del género de Europa, Medio Oriente y el norte de África hasta el extremo occidental del Paleoatlántico. También se amplía el rango temporal del género, de estar conferido al Cenomaniano-Turoniano ahora su existencia se reconoce potencialmente entre el rango Aptiano-Turoniano o al menos Albiano-Turoniano. Esta nueva especie representa el registro más antiguo del género y el primero en América formalmente estudiado.
Análisis filogenéticos realizados con los criterios de optimalidad de Máxima Parsimonia e Inferencia Bayesiana, coinciden en recuperar a †Saurorhamphus de El Espinal como el integrante más tempranamente divergente de †Eurypholinae. La estimación de los tiempos de divergencia con elmodelo deFossilizedBirth–Death(Nacimiento-Muerte fosilizado), ubican la edad media del origen de †Enchodontidae durante el Cretácico temprano, hace 131.9 m.a., en el Hauteriviano. Esta edad corrobora diversos reportes que sitúan el origen del grupo durante finales del Cretácico temprano.
Las filogenias generadas en este trabajo recuperan al género †Saurorhamphus como parafilético. No obstante, este es el primer ejercicio que incorpora a todas las especies formalmente descritas del género y las analizaen un contexto filogenético. Trabajos adicionales son requeridos tanto en la revisión de caracteres incluidos en la matriz y su tipo de codificación, así como con la observación directa de los especímenes fósiles.
En este trabajo se considera que †Saurorhamphus de El Espinal poseía una dieta piscívora, como evidenciado por su gran hocico y sus dientes puntiagudos. El alargamiento del cráneo y del cuerpo también señalan que este pez era un depredador que acechaba desde el fondo marino o bien se ocultaba entre las plantas o rocas para capturar a sus presas. La presencia de una aleta dorsal hipertrofiada, semejante a una vela de bote, propiciaba a esta especie mayor control al momento de realizar movimientos súbitos durante el nado o la caza.
†S. de El Espinal incrementa la cantidad de Aulopiformes fósiles y de otros osteíctios originalmente reportados en los dominios del Tetis central y occidental que también habitaron en el extremo occidental de Paleoatlántico. Esto sugiere que estos territorios se mantuvieron conectados y que las faunas marinas se intercambiaban o dispersaron entre estas zonas. La presencia de †Saurorhamphus en el sureste de México consolida a esta región como una de las más diversas en encodóntidos de todo el mundo durante finales del Cretácico temprano y comienzos del Cretácico tardío.
... This separation probably limited the diet competition between the three contemporaneous species, a distribution previously observed in dyrosaurids from the Oulad Abdoun Basin of Morocco in several stratigraphic levels (Jouve, 2004;Bardet et al., 2010), the Palaeocene of the Cerrejon Formation in Colombia (Hastings, 2012) and the middle Eocene of Germany (Hastings & Hellmund, 2017). Such niche partitioning has also been suggested for Mesozoic marine thalattosuchians (de Andrade & Young, 2008), freshwater crocodyliforms (Moreno-Bernal et al., 2006) and marine Mesozoic squamates (Bardet, 2012;Bardet et al., 2015). ...
Numerous aquatic crocodyliforms have been found during the last four decades of fieldwork in the Maastrichtian El Molino and Palaeocene Santa Lucía Formations in Bolivia. We describe new material in detail and review previously described specimens. This work enables identification of at least three new Palaeocene dyrosaurid species and the reassignement of the Maastrichtian crocodylian Dolichochampsa minima to Gavialoidea. Dolichochampsa minima is thus the oldest known South American member of this clade; previously, gavialoids were known from this continent only since the late Eocene. A new phylogenetic analysis suggests that Vectisuchus leptognathus and Elosuchus are more closely related to Dyrosauridae, and a new name, Dyrosauroidea, is proposed for this clade. Several characters previously considered as typical for dyrosaurids are present in Elosuchus. Comparison of this phylogenetic analysis with geographical and temporal distributions helps to reveal a new scenario for dyrosaurid dispersal. A high number of intercontinental interchanges occurred during the Maastrichtian, whereas higher intracontinental diversification occurred during the lower Palaeocene.
... This includes the slender, labiolingually compressed and weakly distally and lingually recurved shape of the crown, its subsymmetrical cross section, convex lingual and labial faces, smooth but sharp carinae, a slightly irregular primary striation and weak, concave facets which cover only the basal part of the crown (see e.g., Lindgren, 2004;Bengtson and Lindgren, 2005). A similar dental morphology is present in the merely fragmentarily known Platecarpus(?) somenensis Th evenin, 1896 from the Campanian of northeast France and, possibly, southern Sweden (Th evenin, 1896; Lindgren, 2004;Bardet, 2012). However, in this form the lingual face bears more facets. ...
Isolated remains of mosasaurids and plesiosaurians are recorded from the lower Campanian Bottrop
and Vaals formations of North Rhine-Westphalia, western Germany. A tooth crown from Bottrop-
Fuhlenbrock, referred to an elasmosaurid plesiosaurian, represents the first record of this group from
late-Upper Cretaceous strata of the area. Another presumed plesiosaurian remain is a fragmentary
gastralium from Duisburg-Walsum. Some of the mosasaurid material from the Bottrop Formation (a
tooth crown and vertebrae from Bottrop-Fuhlenbrock and Duisburg-Walsum) is assigned to the
subfamily Plioplatecarpinae. The Vaals Formation, which is a lateral equivalent of the Bottrop
Formation, yielded a single tooth crown, found at Aachen-Bildchen, that is here referred to the genus
Hainosaurus. These finds from the Bottrop and Vaals formations constitute evidence of the presence
of these taxa in proximal shelf to nearshore settings during the Campanian. The mosasaurid
occurrences in particular may be an indicator that diversity and abundance increased in more
basinward facies and greater palaeowaterdepth.
... Mosasaur fossils have been known for approximately 250 years, fossils from around the world have been referred to the type species (Bardet, 2012b;Bardet et al. 2014) and yet the taxonomy of the type genus and species are incredibly unstable owing to the improper way in which the names were erected. Stabilizing the concept of Mosasaurus in order to ensure the longevity and informative value of the genus is thus of great importance. ...
The large Late Cretaceous marine reptile
Mosasaurus
has remained poorly defined, in part owing to the unorthodox (by today's nomenclatural standards) manner in which the name was erected. The lack of a diagnosis accompanying the first use of either the genus or species names allowed the genus to become a catchall taxon, and subsequent diagnoses did little to refine the concept of
Mosasaurus
. We herein present emended diagnoses for both
Mosasaurus
and the type species
M. hoffmannii
, based solely on personal examination of the holotype, and a description of the type species based on personal examination of many specimens.
Mosasaurus
exhibits a premaxilla with a short, conical edentulous rostrum, a maxilla with little to no dorsal excavation for the external naris, posteromedial processes of the frontal that deeply invade the parietal, a quadrate taller than long with a short suprastapedial process and the stapedial pit dorsal to the mid-height of the shaft, an angular that is laterally visible for only a short length of the post-dentary unit, a very tall surangular, a humerus with the postglenoid process robust and offset and a distal width greater than the length, and a pubis with an anteriorly projecting tubercle.
M. hoffmannii
is distinguished from other species assignable to the genus by the anteroventral corner formed on the tympanic rim of the quadrate, the asymmetric carinae of the anterior marginal teeth dividing the tooth circumference into short labial and long lingual segments, and the proximal and distal expansion of the femur.
... Morocco (Arambourg, 1952; Bardet et al., 2008; Schulp et al., 2010), Jordan (Mustafa & Zalmout, 2001), Bulgaria (Tzankov, 1939), Russia and the Ukraine (Schulp et al., 2006), suggesting that the genus ranged through most of the Atlantic and Tethyan realms (Fig. 1). Intriguingly, it had not yet been recorded from the Atlantic coast of North America (compare Bardet, 2012). ...
Four recently collected tooth crowns of the rare latest Cretaceous (late Maastrichtian) durophagous mosasaur Carinodens belgicus are discussed; the first record from the Atlantic coast of North America (Maryland), and three additional in situ examples from the Maastrichtian type area in the southeast Netherlands and northeast Belgium. Also presented are an updated overview of the material recorded to date, and a discussion of the palaeobiogeographical and palaeoenvironmental distribution of the genus. Towards the end of the Cretaceous, Carinodens appears to have been successful in exploiting the margins of both the proto-Atlantic Ocean and the Tethyan Realm.
... The situation was further obscured when Zangerl (1953) erected the Osteopyginae to include a chimeric Osteopygis and durophagous sea turtles from the Cenozoic of Europe with typically chelonioid postcrania. Since then, the association of durophagous sea turtles with Osteopygis or Osteopyginae became fully entrenched in the literature (e.g., Foster, 1980;Fastovsky, 1985;Weems, 1988;Hirayama, 1994;Parham and Fastovsky, 1997;Hirayama and Tong, 2003), including some recent papers that were published after Parham (2005; e.g., Bardet, 2012;Sato et al., 2012). With the exception of one study that provided no counterargumentation or evidence (Tong et al., 2012), every study that cites Parham (2005) accepts the distinction between the chelonioid skulls and "macrobaenid" postcrania (e.g., Kear and Lee, 2006;Brinkman et al., 2009;Jalil et al., 2009;Brinkman, 2013). ...
... The collapse in marine productivity triggered by a bolide impact at the K/Pg boundary resulted in the extinction of these successful openocean marine predators, while marine snakes, turtles, and crocodilians (e.g. Dyrosauridae) survived (Bardet, 2012). ...
... At that time, mosasaurids dispersed widely in the epicontinental seas that covered Europe (Bardet and Pereda Suberbiola 1996) and the rest of the world. Due to their ability to enter open seas, various taxa were common to several continents; however, as for the Cenomanian, the fauna of the European margin of the Tethys was significantly different from that of the southern margin (Bardet 2012b). During the latest Cretaceous, some species were over 10 m long and, therefore, were the largest mosasaurids that ever existed. ...
Squamates first appeared in Europe in the Middle Jurassic. They were lizards that already included some crown-group members. Faunas of the Late Jurassic and Early Cretaceous were more or less a continuation of the Middle Jurassic assemblage. The early Late Cretaceous was characterised by a peculiar fauna of marine pythonomorphs, while terrestrial forms were rare. In the subsequent levels of the Late Cretaceous, marine forms were mainly mosasaurids; terrestrial assemblages heralding modern ones began to take form during the Campanian-Maastrichtian. The Cretaceous-Tertiary event did not strongly affect squamates in Europe. After poor Paleocene faunas, a big wave of dispersals reached Europe during a marked rise in temperature at the beginning of the Eocene (MP 7). The Eocene fauna was rich, diverse and of tropical type. In western Europe, a sharp extinction event ('Grande Coupure') eliminated most squamates at the end of the Eocene, but its impact in central and eastern Europe is unknown. The Oligocene fauna was transitional between the 'old' Eocene and the modern Miocene faunas. By the late early Miocene (MN 3-MN 4), the fauna markedly changed when an important wave of dispersals entered Europe during a climatic optimum. From the late middle Miocene onward, the temperature has dropped. As a consequence, faunas became less rich and regionalisation occurred. Numerous extinctions and withdrawals took place during the late Pliocene and early Pleistocene, leaving an impoverished fauna in Europe.
Everybody knows many names of animals and plants, but very few have the slightest idea about how scientists go about naming groups of biological organisms (called “taxa”) and how these names are applied to these groups. Yet, with the explosion in our knowledge of biodiversity over the last three centuries (about 1.5 million species have been named, so about as many groups of species could potentially be named), an efficient nomenclatural system is of critical importance. A good nomenclatural practice is also of great societal importance given that it is required to fight the rapid erosion of biodiversity linked with the explosion of human populations in the last centuries. The system currently used by most practicing systematists (the biologists who describe and classify the biodiversity), known as rank-based nomenclature, harks back to the works of Linnaeus in the mid-18th century and the Strickland code, which was inaugurated in 1843. When Linnaeus proposed his system, most scientists were creationists and fixists, whereas modern biology has provided ample proof that Life has been evolving on Earth for more than 3 billion years. It is thus not unexpected that a growing number of scientists find rank-based nomenclature inadequate. This problem is linked to the fact that rank-based nomenclature aims at not delimiting taxa precisely, a goal that is arguably opposite to that of most other sciences, such as geology, chemistry and geography, and which hampers our ability to communicate efficiently about taxa. Consequently, a group of scientists has developed a new code of biological nomenclature based on new principles, called phylogenetic nomenclature. This new code, called the PhyloCode, took effect in April 2020.
This book seeks to describe the history of how groups of animals and plants have been named, starting with the prehistory but focusing on the last three centuries. More importantly, it describes the underlying events and issues that have shaped this history, such as developments in systematics, evolutionary biology and phylogenetics. It outlines the current controversies and challenges facing biological nomenclature in the 21st century
A B S T R A C T
The Cretaceous-Paleogene (K-Pg) transition saw mass extinctions in terrestrial and marine ecosystems. Terrestrial vertebrate diversity patterns across the K-Pg boundary have seen extensive study, but less is known about marine vertebrates. We describe a new mosasaurid from the latest Maastrichtian phosphatic beds of Morocco, showing how mosasaurids evolved to become apex predators in the latest Cretaceous. Thalassotitan atrox n. gen. et sp., from the Oulad Abdoun Basin of Khouribga Province, Morocco is characterized by large size, a broad skull, massive jaws, and reduced cranial kinesis, suggesting it was highly adapted for carnivory. Teeth resemble those of killer whales in their robust, conical shape, and show heavy wear and damage. Phylogenetic analysis recovers Thalassotitan as a close relative of Prognathodon currii and P. saturator within the Prognathodontini. Among the associated fauna, three genera of mosasaurids, elasmosaurid plesiosaur, chelonioid turtle, and enchodontid fish show acid damage, and could be prey ingested by mosasaurids, likely Thalassotitan. Thalassotitan shows mosasaurids evolved to fill the marine apex predator niche, a niche occupied by orcas and white sharks today. Mosasaurs continued to diversify and fill new niches until their extinction at the end of the Cretaceous.
Numerous aquatic crocodyliforms have been found during the last four decades of fieldwork in the Maastrichtian El Molino and Palaeocene Santa Lucía Formations in Bolivia. We describe new material in detail and review previously described specimens. This work enables identification of at least three new Palaeocene dyrosaurid species and the reassignement of the Maastrichtian crocodylian Dolichochampsa minima to Gavialoidea. Dolichochampsa minima is thus the oldest known South American member of this clade; previously, gavialoids were known from this continent only since the late Eocene. A new phylogenetic analysis suggests that Vectisuchus leptognathus and Elosuchus are more closely related to Dyrosauridae, and a new name, Dyrosauroidea, is proposed for this clade. Several characters previously considered as typical for dyrosaurids are present in Elosuchus. Comparison of this phylogenetic analysis with geographical and temporal distributions helps to reveal a new scenario for dyrosaurid dispersal. A high number of intercontinental interchanges occurred during the Maastrichtian, whereas higher intracontinental diversification occurred during the lower Palaeocene.
Kear, B.P., Fordyce, R.E., Hiller, N. & Siversson, M., December 2017. A palaeobiogeographical synthesis of Australasian Mesozoic marine tetrapods. Alcheringa 00, 000-000. ISSN 0311-5518.
THE LAST 15 years has witnessed a blossoming of research on Australasian Mesozoic marine tetrapod fossils. Much of this work has focused on amniotes, particularly those from the prolific Lower Cretaceous (Aptian–Albian) Lagerstätten of the Eromanga Basin in central and eastern Australia, and Upper Cretaceous (Campanian–Maastrichtian) sequences of the North and South islands of New Zealand. However, rare and less popularized remains have also been found in Lower Triassic–mid-Cretaceous rocks from Australia, New Zealand and the Chatham Islands, and on the tectonically proximal landmasses of New Caledonia and Timor. Currently identified taxa include estuarine–paralic rhytidostean, brachyopid, capitosaurian and trematosaurian temnospondyls from the earliest Triassic (Induan–Olenekian), Middle–Late Triassic (Anisian–Norian) eosauropterygians, and mixosaurian, shastasaurian and euichthyosaurian ichthyosaurians, Early–Middle Jurassic (Sinemurian–Bajocian) ichthyosaurians, together with plesiosauroid and rhomaleosaurid-like plesiosaurians, and diverse Early (Aptian–Albian) through to Late Cretaceous (Campanian–Maastrichtian) elasmosaurid, leptocleidid, polycotylid, probable cryptoclidid and pliosaurid plesiosaurians, as well as ophthalmosaurid ichthyosaurians, sea turtles incorporating protostegids, and mosasaurid squamates. This faunal succession evidences almost continuous occupation of southern high-palaeolatitude seas, and repeated endemic diversifications (including nascent members of some key lineages) amongst emigrant cosmopolitan clades. The primary dispersal routes are likely to have been peri-Gondwanan, with coastal migrations along the western Tethys and polar margins of the Panthalassan Ocean. However, augmentation by increasing continental fragmentation and seaway corridor connectivity probably occurred from the Middle Jurassic to Late Cretaceous. Latest Cretaceous mosasaurid and elasmosaurid taxa also reveal regional affinities with the emergent western Pacific and Weddellian austral bioprovinces. The extreme rarity, or complete absence, of many major groups prevalent elsewhere in Gondwana (e.g., tanystropheids, Triassic sauropterygians, bothremydid marine turtles, thalattosuchians and dyrosaurid crocodylomorphs) is conspicuous, and might be related to stratigraphical/collecting biases, or the predominantly higher-palaeolatitude, cooler-water Mesozoic palaeogeography of the Australasian region. Although the burgeoning record is substantial, much still awaits discovery and adequate documentation; thus Australasia is still one of the most exciting prospects for future insights into the global history of Mesozoic marine tetrapods.
Benjamin P. Kear* [benjamin.kear@em.uu.se] Museum of Evolution, Uppsala University, Norbyvägen 16, SE-752 36 Uppsala, Sweden; R. Ewan Fordyce [ewan.fordyce@otago.ac.nz] Department of Geology, University of Otago, Post Box 56, Dunedin 9054, New Zealand; Norton Hiller [norton.hiller@gmail.com] Canterbury Museum, Rolleston Avenue, Christchurch 8013, New Zealand; Mikael Siversson [mikael.siversson@museum.wa.gov.au] Western Australian Museum, 49 Kew Street, Welshpool, Western Australia 6106.
Abstract The Upper Cretaceous outcrops of Armuña (Segovia Province, Spain) yielded relatively abundant material of vertebrates during prospection and excavation in the second half of the 1980s. However, little has been published on these remains. A new analysis of the specimens from this upper Campanian site reveals the presence of some clades in the site for the first time (e.g., Dortokidae, Anguimorpha, Mosasauroidea). Furthermore, the material of the clades previously recognized there has been reviewed and described in more detail, with some previous systematic attributions confirmed and others refuted. Consequently, a relatively high local diversity has been identified. New taxa (i.e., a member of Anguimorpha and a eusuchian crocodyliform) are identified in Armuña, coexisting with other taxa previously described in other sites from the Iberoarmorican Realm. The vertebrates from Armuña confirm that the fauna from the Upper Cretaceous of the Iberian Peninsula is composed of a mixture of European e
We report on new mosasaurid remains, namely isolated teeth, from the Upper Maastrichtian shallow marine environment of Albaina in the Laño quarry (Condado de Treviño). The new specimens belong mostly to mosasaurines, i.e., Mosasaurus hoffmanni, Prognathodon solvayi, Prognathodon sectorius, and to the russellosaurine plioplatecarpine Platecarpus cf. ictericus. Prognathodon solvayi and Platecarpus cf. ictericus were previously known from Albaina. This is the first mention in the site of Mosasaurus hoffmanni, widespread in Maastrichtian outcrops located around palaeolatidude 30-40°N, from New Jersey (USA) to Turkey passing through Europe where it is commonly found. Prognathodon sectorius has a comparable palaeobiogeographical distribution, though not so expanded, that M. hoffmanni, being known in the Maastrichtian of New Jersey (USA) and Europe and, since recently, in the Campanian of Navarre. With six different taxa reported here, Albaina is the richest outcrop in specific mosasaurid diversity from the Maastrichtian of southern Europe.
The vertebrate-bearing beds of the Laño quarry (Condado de Treviño) are among the most relevant sites from the Late Cretaceous of Europe. Geologically, Laño and the adjacent region are set on the southern limb of the South-Cantabrian Synclinorium (SE Basque-Cantabrian Region, northern Iberian Peninsula). The Laño sites were discovered in 1984; thousands of bones and teeth, including microfossils, have been collected during the prospection in the field and excavation campaigns. The vertebrate remains occur at two different stratigraphic horizons within a continental to shallow marine succession of Late Campanian-Maastrichtian age. The lower horizon contains the Laño 1 and Laño 2 sites, whereas the upper horizon contains the Albaina site. In the Laño sites, three fossiliferous beds (called L1A, L1B and L2) are known within an alluvial system composed mainly of fluvial sands and silts. The sedimentary structures are consistent with channel areas within an extensive braided river system. Based mainly on stratigraphic correlations, the fluvial beds of Laño are regarded as Late Campanian to Early Maastrichtian in age. These deposits have yielded a very diverse vertebrate assemblage, which consists of nearly
40 species, including actinopterygians, lissamphibians, lepidosaurs, turtles, crocodyliforms, dinosaurs, pterosaurs, and mammals. Seven genera and ten species have been erected to date in Laño. With reference to the marine vertebrate association of Albaina, it consists of at
least 37 species, including sharks and rays, actinopterygians, mosasaurids, and plesiosaurs. Two genera and species of rhinobatoids (family
indet.) and two new species of rhinobatids have been erected in Albaina. The fossil association indicates a Late (but not latest) Maastrichtian age. Recently, isolated turtle and dinosaur fossils have been discovered in the sublittoral beds of Albaina. The Laño quarry is one of the most noteworthy Campanian-Maastrichtian vertebrate localities of Europe by its taxonomic diversity, and provides useful information about the composition and affinities of both continental and marine vertebrate faunas from the latest Cretaceous of southwestern Europe.
In recent years, the discovery of isolated teeth from the Late Cretaceous (Campanian-Maastrichtian) of the Basque-Cantabrian
Region, in the north of the Iberian Peninsula, has permitted to recognise at least four different mosasaurid taxa in several
sites of Alava and Condado de Treviño: Mosasaurus lemonnieri, Prognathodon solvayi, Platecarpus cf. ictericus and Tylosaurus sp. A new specimen, which consists of a fragment of skull with articulated portions of the maxilla and prefrontal, from the
Campanian of Navarre is described here. This material is assigned to Prognathodon cf. sectorius on the basis of dental features. It constitutes the only cranial remain and the most significant mosasaurid fragment known
to date in the Iberian Peninula. P. sectorius was previously recorded from the Maastrichtian of New-Jersey and The Netherlands.
Fig. 1
Jean-Claude Rage climbing a rope ladder during a palaeontological excavation campaign in Quercy (southwestern France) in 1976 (photo EB).
Jean-Claude Rage has been recognized for several decades as one of the leading and international experts in the field of palaeontology, which he largely contributed to develop and which could be called “micro-palaeoherpetology”. As an introduction to a collection of papers in his honour, this short biographical sketch, authored by two colleagues of Jean-Claude (one of whom also is a former PhD student of his) is meant to convey our appreciation of his remarkable scientific and personal achievements.
Jean-Claude Rage is currently Emeritus Research Director at the CNRS (National Centre of Scientific Research) and is based at the Museum National d'Histoire Naturelle in Paris. He is married to Pr. Agnes Lauriat-Rage (an expert on fossil molluscs and retired MNHN Professor). Jean-Claude was born on 1st March, 1943 at Lyon, France. After attending high school at Saint-Etienne, in central France, he returned to Lyon in 1963 to study at the university, while keeping links with Saint-Etienne, where he worked as an auxiliary teacher until 1965. He became assistant reader at the University of Lyon (1965-1968), where he obtained his Master Degree in 1967. His third cycle thesis (“these de 3eme cycle” – a now defunct French degree) on Quaternary anurans, prepared under the supervision of Prof. Louis David, was defended in 1968. Then Jean-Claude left (temporarily) fossil amphibians (and the city of Lyon) for reptiles (and the city of Paris), where he defended in 1976 his Ph-D (“Doctorat d'Etat”) on snake anatomy, origins and evolution, under the supervision of Prof. Robert Hoffstetter (University Paris 6).
Jean-Claude's long association with the Centre National de la Recherche Scientifique (CNRS) began in 1968, when he obtained a temporary position there, which soon turned …
We present the δ13C and paleomagnetic stratigraphy for marine strata at the coast of southern Angola, anchored by an intercalated basalt with a whole rock 40Ar/39Ar radiometric age of 84.6 ± 1.5 Ma, being consistent with both invertebrate and vertebrate biostratigraphy. This is the first African stable carbon isotope record correlated to significant events in the global carbon cycle spanning the Late Cenomanian to Early Maastrichtian. A positive ∼ 3‰ excursion seen in bivalve shells below the basalt indicates the Cenomanian-Turonian Boundary Event at 93.9 Ma, during Oceanic Anoxic Event 2. Additional excursions above the basalt are correlated to patterns globally, including a negative ∼ 3‰ excursion near the top of the section interpreted as part of the Campanian-Maastrichtian Boundary Events. The age of the basalt ties the studied Bentiaba section to a pulse of Late Cretaceous magmatic activity around the South Atlantic and significant tectonic activity, including rotation, of the African continent.
Se analizan las faunas de reptiles marinos del Cretácico final (Santoniense a Maastrichtiense) de Europa, en el margen norte del mar de Tetis mediterráneo, desde un punto de vista sistemático y bioestratigráfico. Se establece una correlación entre las principales formaciones y las zonas de belemnites. Las faunas de reptiles marinos de la provincia europea situadas entre los 30° y 40° N de latitud estan dominadas por los mosasaurios y las tortugas Chelonioidea. Los plesiosaurios (elasmosaurios y pliosaurios) son bastante escasos y provienen de las localidades más septentrionales (a partir de 40° N). Los cocodrilos Dyrosauridae y las serpientes Paleophidae no estan representados en el registro fósil europeo. Este modelo de distribución de los reptiles marinos parece estar controlado por los gradientes latitudinales.
Research undertaken in several Cretaceous layers of New Jersey permited to list a rich selachian fauna. Especially, the upper Campanian layers of Hop Brook and Willow Brook gave us, after washing and sifting, an interesting microichthyofauna and macrofauna. Among the 28 species identified, 10 were previously unknown: Lonchidion babulskii n. sp., Plicatolamna borodini n. sp., Hypotodus aculeatus n. sp., Odontaspis holmdelensis n. sp., 0. hardingi n. sp., 0 . samhammeri n. sp., Ginglymostoma globidens n. sp., Ptychotrygon cuspidata n. sp., Ankystrorhynchus major n. sp. and Rhombodus levis n. sp. In addition, a new subspecies of Cretolamna appendiculata is proposed for the populations of Maroccan Montian: C. appendiculata arambourgi n. subsp.
Besides cosmopolitan elements, this fauna contains 54% unknown species outside of the Atlantic coastal plain of U.S.A. This large proportion of species peculiar to this region probably points out different conditions of life from those existing then in Europe and Africa.
A study of the literature, related to the vertebrate faunas of the phosphates of Morocco, does not reveal the discovery of turtle remains. Individual shell plates, limb bones and an almost complete carapace recently discovered
indicate the presence of a pelomedusid fauna throughout these Cretaceous and Tertiary deposits.
An isolated hyoplastron of a chelonioid sea turtle is reported from the Maastrichtian (Upper Cretaceous) deposits of the Ouled Abdoun phosphate basin, Morocco. It closely resembles that of the Late Cretaceous dermochelyid, Corsochelys haliniches from Alabama (USA) and is referred to the family Dermochelyidae. The find from Morocco is the first record of a dermochelyid turtle from the Cretaceous of Africa and indicates a vast geographical distribution of the family during that period.
Isolated skeletal remains of elasmosaurid plesiosaurs are described from the upper Upper Maastrichtian of the type area of that stage and compared with material from the Maastrichtian of southern Belgium (Mons Basin) and Morocco. An overview of Maastrichtian elasmosaurids worldwide is presented. The rarity of elasmosaurids in the latest Cretaceous marginal seas of the type Maastrichtian as compared with their common occurrence in the oceanic waters near California and Morocco of that age may be related to food abundance in upwelling areas along the margins of continental plates.
The discovery of new specimens of Pachyvaranus crassispondylus Arambourg, 1952 from the Maastrichtian phosphates of Morocco and Syria enables us to (1) redescribe in detail this poorly known varanoid lizard, (2) provide a more detailed diagnosis and (3) re-evaluate the systematic affinities of this taxon within squamates. The latter is placed in Pachyvaranidae nov., considered a new unranked clade of non-pythonomorph Varanoidea. The intense pachyosteosclerosis observed in the vertebrae and ribs suggests a primarily aquatic mode of life for Pachyvaranus. This is in accordance with the sedimentological context (shallow marine environment). As for its palaeobiogeographical distribution, Pachyvaranus is a component of the marine reptile assemblages from the southern margin of the Mediterranean Tethys, around palaeolatitudes 20 • N. The osteoderms previously referred to this taxon by Arambourg are reanalysed and assigned to a teleost fish.
A new specimen of the basal mosasaur Halisaurus platyspondylus from the Severn Formation of Prince Georges County, Maryland (Upper Cretaceous: middle Maastrichtian) represents the most complete partial skeleton of this uncommon taxon to be described to date. The characteristic dorsoventral compression of the vertebral centrum is most pronounced in the anterior trunk vertebrae, and the centra of the posterior trunk vertebrae exhibit proportions more similar to those in other mosasaurs such as Plioplatecarpus. The postorbitofrontal forms its primary contact with the frontal rather than the parietal, and the supraoccipital is firmly attached to the ventral side of the parietal. The plane of articulation between the parietals and supratemporal is neither vertical (as in Varanidae) nor horizontal (as in Mosasauridae), but forms an angle of about 55 degrees with the horizontal. The quadrate bears a long, ventrally-flared suprastapedial process but appears to lack an infrastapedial process. Close similarities in the structure of the frontal and parietal with “Clidastes” sternbergii support referral of the latter to Halisaurus , but reference of Phosphorosaurus ortliebi to Halisaurus is questionable. Halisaurus has been recorded from the Santonian to the late Maastrichtian.
A historical overview is presented of the (litho)stratigraphic studies into the Upper Cretaceous deposits in southern Limburg (the Netherlands), the type area of the Maastrichtian. From 1860 onward, a workable lithostratigraphy has been available for these deposits. At present, a division including four formations and 23 members is being used.
The Upper Campanian-Lower Maastrichtian chalks of the Mons Basin in Belgium, in ascending order, Craie de Trivieres, Craie d'Obourg, Craie de Nouvelles, Craie de Spiennes, and Craie Phosphatee de Ciply, are tentatively placed in the international stratigraphic framework on the basis of preliminary studies of belemnites and foraminifera, as well some other macrofossils. The top of the Craie de Trivieres, the Craie d'Obourg, the Craie de Nouvelles are from the lower part of the Upper Campanian, and the basal 10-12 m of the Craie de Spiennes from the upper part of the Upper Campanian. The Craie Phosphatee is regarded to be from the upper part of the lower Lower Maastrichtian. -Authors
The holotype of Plesiosaurus houzeaui Dollo, 1909 consists of plesiosaurian bones, discovered in the Spiennes Chalk (Upper Campanian) of the Ciply area (Mons Basin, Belgium). The description of the type material shows that Plesiosaurus houzeaui is an invalid species based on heterogeneous elasmosaurid and also probably non-elasmosaurid plesiosaurian material. A review of plesiosaurian material previously described from the Upper Cretaceous of Europe indicates that Elasmosauridae and Pliosauridae are represented. Polyptychodon is the only valid genus of pleiosaur from the Upper Cretaceous of Europe. -Authors
Presents a description of the skull of species of the genus Halisaurus Marsh 1869. Halisaurus ortliebi (= Phosphorosaurus ortliebi of Dollo, 1889), from the Maastrichtian of Belgium, shows, several character states, including a unique ventral fossa of the parietal. Comparisons are made with the North American H. platyspondylus. H. sternbergi (Wiman, 1920) is no longer considered as belonging to the genus Halisaurus.
The first detailed morphological description of Mosasaunis lemonnieri is presented. Comparisons are made with other mosasaurs and a number of extant reptiles, principally among the "lizard" families. A number of intraspecific variable characters, including an unusually high number of pygal vertebrae, are noted. The study shows that there are considerable similarities between M. lemonnieri and Mosasaunis hoffmanni, which supports an earlier cladistic analysis indicating sister taxa status between the two forms. However, the latter is a considerably more robust and gigantic taxon. Previous assignment to M. conodon is rejected here. M. lemonnieri was less widespread than A/, hoffmanni with main occurrences in Belgium and to a lesser extent The Netherlands. M. lemonnieri was clearly a dominant mosasaur in the Belgian locality judging by the large quantity of its remains discovered there.
Globidens and Carinodens from the Upper Cretaceous of Belgium and The Netherlands respectively are described. They were the first marine reptiles since the placodonts of the Triassic and the ichthyosaur Grippia from the Triassic of Spitzbergen that were specialized for durophagous feeding. Two tooth types are identified in Globidens-a spherical type, fairly smooth with a small nubbin or point and a subspherical form, with a highly striated surface and a large apical nubbin. The entire dental row of Carinodens is reconstructed to show, in lateral view, pointed teeth anteriorly, triangular teeth towards the middle and rectangular teeth posteriorly. Both the tooth shape and the wrinkled surface played an important part in the stresses the teeth were subjected to. Carinodens probably fed on thin shelled invertebrates and Globidens on thicker shelled invertebrates and vertebrates. Durophagy also occurred in other mosasaurs such as Mosasaurus hoffmanni, Prognathodon, and members of the Tylosaurinae, although in these forms it is considered to have been opportunistic and part of a wider feeding strategy.
Arambourgiania Philadelphias (ARAMBOURG 1959) from the Maastrichtian (Upper Cretaceous) of Ruseifa, Jordan, is one of the largest pterosaurs known and was an animal comparable in size to the North American pterosaur Quetzalcoatlus northropi. A recent visit to Jordan failed to locate the holotype of A. philadelphiae (ARAMBOURG), although new, but fragmentary remains from the type locality were discovered. The new remains may be referable to Arambourgiania and are clearly distinct from Quetzalcoatlus. Calculations suggest that the wing span of Arambourgiania may have reached 12 meters.
Mosasaur remains coming from the late Early Campanian of Reims area, Champagne, are described and attributed to Prognathodon giganteus DOLLO, 1904 on the basis of dental characters. The anastomosed aspect of the enamel is here regarded as a diagnostic feature of this species. This is the first mention of Prognathodon in the Campanian of Europe and probably the earliest known mention of the genus. Moreover, this is the first time that the species Prognathodon giganteus is described outside the Maastrichtian of Belgium.
