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New and rare Cenomanian crabs (Crustacea, Decapoda, Brachyura) from the Paris Basin (France), and a comparison with necrocarcinids, etyids and dynomenids from Devon (England)
Abstract
The crab fauna from the lower Cenomanian of Normandy and Sarthe is rich and diverse. Species rarely observed and two new necrocarcinids are described. Necrocarcinus inornatus sp. nov. is distinguished by its very weakly developed tuberculation, and Paranecrocarcinus pusillus sp. nov. has an ornament that differs from any other species of the genus. A comparison between the lower Cenomanian crab faunas of Pétreval (Normandy) and Wilmington (Devon) shows that the faunas are similar, all species restricted to one of the areas being rare or very rare species. Species from the Cenomanian of Pétreval, in common with those from Devon, show a remarkable agreement in specific characters, and, when an estimation is possible, in intraspecific variability.
... Infraorder Brachyura Latreille, 1802Section Raninoida Ahyong, Lai, Sharkey, Colgan and Ng, 2007Superfamily Necrocarcinoidea Förster, 1968Family Paranecrocarcinidae Fraaije, Van Bakel, Jagt and Artal, 2008 Genus Pseudonecrocarcinus Förster, 1968 Wright and Collins (1972), Late Cretaceous (Cenomanian), UK; P. digitatus (Wright and Collins, 1972), Late Cretaceous (Cenomanian), UK; P. eichhorni n. sp. (herein); P. foersteri (Wright and Collins, 1972), Late Cretaceous (Cenomanian), UK; P. gamma (Roberts, 1962), Late Cretaceous (Campanian), USA; P. graysonensis (Rathbun, 1935), Early Cretaceous (Albian), USA; P. milbournei Collins, 2010, Late Cretaceous (Cenomanian), Nigeria; P. moseleyi (Stenzel, 1945), Early Cretaceous (Albian), USA; P. pusillus (Breton and Collins, 2011), Late (including epibranchial tooth), slightly increasing in size posteriorly; posterolateral margin nearly straight, fringed with small spines, decreasing in size posteriorly; posterior margin slightly concave medially; dorsal carapace covered by granules uniformly arranged, larger on the metabranchial and intestinal regions; short deep branchiocardiac grooves, delimiting cardiac region; smooth epigastric region slightly depressed; postorbital region inflated frontally; postorbital and hepatic regions finely granulate, slightly depressed; hepatic region with one small tubercle near the lower of anterolateral margin; inflated protogastric regions with two distinct rounded equal tubercles; mesogastric region with two rounded stout tubercles, the anterior one larger; metagastric region with two deep gastric pits; cardiac region separated by gastric regions by wide depressed urogastric region; cardiac region rounded, inflated, with two equal tubercles ranged transversally; branchial regions moderately expanded laterally, convex, inflated, with rounded protuberances; epibranchial region with one tubercle; mesobranchial region with two contiguous tubercles ranged longitudinally, the anterior one slightly smaller; metabranchial region with one stout tubercle; flat, short, and granulate intestinal region. ...
The new species, Pseudonecrocarcinus eichhorni (Paranecrocarcinidae Fraaije, Van Bakel, Jagt and Artal, 2008) from the Late Cretaceous (Coniacian) of Montana is herein described. This new species represents the second report for the genus from the Late Cretaceous of USA.
... During the Cretaceous, brachyurans were living in a variety of environments in Europe and not primarily in reef environments (e.g., Wright and Collins, 1972;Collins et al., 1995;Breton and Collins, 2011;Klompmaker, 2013a;Robin et al., 2019). This environmental differentiation may have played a key role in their recovery and diversification during the Cretaceous after a loss of diversity in the earliest Cretaceous Schweitzer and Feldmann, 2015). ...
The Late Jurassic marks the first major radiation among true crabs (Brachyura) in reef environments, followed by another diversification in the mid- to Late Cretaceous in multiple habitats. We studied brachyuran carapaces from Mesozoic sponge- and coral-associated limestones in Europe. Six new taxa are described: Late Jurassic Europrosopon gen. nov., Eodromites bernchrisdomiorum sp. nov., Prosopon josephcollinsi sp. nov., Tanidromites nightwishorum sp. nov., and T. weinschenki sp. nov.; and mid-Cretaceous Eodromites cristinarobinsae sp. nov. Furthermore, we recognize four junior synonyms: Eodromites grandis (=E. guenteri), Tanidromites scheffnerae (=T. wysokaensis), and Europrosopon aculeatum (=E. verrucosum and E. barbulescuae). Five taxa are reassigned: Eodromites aequilatus to Tanidromites, Tanidromites rotundus to Eodromites, Nodoprosopon dzhafarberdensis to ?Abyssophthalmus, Nodoprosopon from Nodoprosopidae to Homolodromiidae, and Rathbunopon from Glaessneropsidae to Prosopidae. Several other taxa are redescribed. The latter reassignment indicates that Rathbunopon does not represent an example of extreme convergent evolution as implied previously. Conversely, the frontal structure consisting of a rostrum with two diverging spines and outer orbital spines appears a remarkable example of convergent evolution of the goniodromitid Navarradromites toward members of Homolodromiidae, for which this frontal structure is characteristic. Rostral spines represent another example of convergent evolution. Some specimens are extraordinary: A specimen of Abyssophthalmus cf. A. spinosus represents the largest complete reported Jurassic brachyuran thus far and one specimen of Planoprosopon aff. P. hystricosus bears one of the largest known parasitic isopod-induced swellings (ichnotaxon Kanthyloma crusta) relative to carapace size. Overall, our results indicate that biodiversity and convergent evolution in Mesozoic brachyurans remain understudied.
... Brachyura evolved and diversified remarkably during the Cretaceous and Tertiary (Jagt et al., 2015). They are found in numerous Cretaceous localities (Jagt et al., 2015), including from the Albian of Iran (Jagt et al., 2014) and the Albian-Cenomanian of southern England, northern France and nothern Spain (see Wright and Collins, 1972;Breton and Collins, 2011;Artal et al., 2012). Martin Glaessner (see in Jagt et al., 2015) distinguished three major radiations in the Brachyura: a podotreme radiation in the Jurassic, a eubrachyuran in the mid-Cretaceous (informally composed of the Albian and Cenomanian), and a thoracotreme radiation in the Early Cenozoic. ...
A considerable Upper Albian sand lithosome, developed on the external margin of the Albian epicontinental sea in the Polish Jura Chain (Miechów Synclinorium, southern Poland), is recognized as a shallowing-up sequence within the generally transgressive Albian sands. In particular, burrows described as the ichnospecies Psilonichnus upsilon Frey Curran and Pemberton, 1984 have a particular ecologic and sedimentological significance, and constitute the primary focus of this paper. In the Glanów-Stroniczki section (Cracow Upland, southern Poland), such burrows seem to be a crucial tool in the interpretation of basin bathymetry, indicating a foreshore to backshore (beach) facies and probably recording a temporary break in sedimentation. They were infilled by sand with pebbles or pebble material, potentially during hurricane or strong storm action. Lithification of the burrow infillings and their enveloping concretionary halos should have progressed in a beachrock mode. The Glanów horst, composed of Jurassic biohermal limestones, was likely an emerged element that neigboured, or was surrounded by, a beach with active fauna. The Psilonichnus upsilon burrows in Glanów-Stroniczki closely resemble burrows of the modern ghost crab Ocypode. In modern settings, representatives of Ocypode are encountered in extremely shallow marine (foreshore/intratidal and backshore/supratidal) to dune environments. The ichnological data from Glanów-Stroniczki suggests that fauna behaviorally similar to Ocypode may have occupied the beach backshore (and to a lesser extent the foreshore) zone near the emerged Glanów horst.
... Even although is not possible to count the "twenty large tubercles" described by Wright & Collins (1972: 66) because the Orxeta specimen is incomplete, at least eighteen of them can be counted. Despite the lateral and posterior margins of this specimens are not well-preserved, and the carapace is somewhat crushed, its overall outline and regions with strong upward directed conical tubercles, match perfectly with the description and figures of Wright & Collins (1972) of British specimens or those of Breton & Collins (2011) of French specimens. In addition, the Spanish specimen presents well-preserved triangular rostrum with small rostral spines on both sides, as was pointed out in the French samples by Breton & Collins (2011: 147). ...
Two species of Cenomanocarcinus (Cenomanocarcinidae) from the late Albian and Turonian of Spain are reported herein, increasing the number of Iberian Cenomanocarcinus species. Likewise, Necrocarcinus woodwardii (Necrocarcinidae) is reported for the first time in the Iberian Peninsula and constitutes the southernmost record for the species. As well, the features of the posterior margin of the cenomanocarcinids Cenomanocarcinus and Hasaracancer, are reviewed and clarified.
A highly diverse decapod crustacean fauna is described from the classic Aptian outcrop of Cal Cassanyes (Castellet i la Gornal) in Catalonia. Although decapod crustaceans are a minor component of the rich invertebrate assemblages at that locality, the just over fifty specimens collected comprise sixteen taxa assignable to the Macrura, Anomura and Brachyura. Of these, the last-named are the most prominent group, comprising eleven species, representing seven families, inclusive of one representative of the Eubrachyura. On the basis of this material, two new genera and five new species are erected, namely Pagurus? garrafensis sp. nov., Garrafosopon gen. nov. angustus (Wright and Collins, 1972) comb. nov., Vectis
blesai sp. nov., Mesodromilites prietoi sp. nov., Necrocarcinus mariae sp. nov. and Iberodorippe vinea gen. nov., sp. nov. In addition, Hoploparia sp., an indeterminate axiid and one paguroid, as well as one indeterminate galatheoid are recorded here. Material of Distefania incerta (Bell, 1863), the commonest species at the study site by far, of Goniodromites laevis (Van Straelen, 1940) and of Etyxanthosia fossa (Wright and Collins, 1972) represents the first Aptian and stratigraphically oldest records for these taxa.
Added to this list are also Eodromites sp., Paranecrocarcinus? sp. and Pseudonecrocarcinus? sp. The high decapod crustacean diversity at Cal Cassanyes establishes this locality as the richest Aptian assemblage from the Iberian Peninsula, but also one of the richest in the world. The faunal assemblages here are dominated by sponges, and the varied composition of the decapod crustacean faunas can be linked to upwelling currents which provided abundant nutrients. In fact, the establishment of sponge communities played a crucial role in activating the food chain and functioned similarly to a patch reef, creating a relatively sheltered environment that facilitated the colonisation of other invertebrate communities, including decapod crustaceans. The latter occupied various trophic levels as both primary and secondary consumers. Current knowledge of Early Cretaceous decapod crustaceans is scant and hinders a thorough palaeobiogeographical analysis. The present study emphasises the challenges surrounding the identification of endemic taxa, thus impacting our understanding of decapod crustacean palaeobiogeography of the late Early Cretaceous.
Necrocarcinus gorbenkoi sp. nov. from the Lyamino Formation (Cenomanian, Upper Cretaceous) from Moscow Region represents the third discovery of crabs in Central Russia and the first member of the genus Necrocarcinus in this geographical area. Morphologically, the new species is close to the species N. bodrakensis Levitskyi, 1974, N. tauricus Ilyin & Alekseev, 1998, and N. labeschii Eudes-Deslongchamps, 1835, but has some differences that allow us to establish a new taxon.
A new necrocarcinid crab, Necrocarcinus christinae, is described from the Cenomanian deposits (Woodbine Formation) of Irving, Texas. Only a handful of decapod species are known from this formation but N. christinae sp. nov. remarkably represents the third palaeocorystoid crab. The size of the sole specimen known is much larger than usual for the genus; only the larger size of N. woodwardii is more or less comparable, and this species is morphologically most similar to this species. The closely allied genus Elektrocarcinus is reviewed and its diagnostic characters are discussed; its composition is here revised.
The sole specimen of Necrocarcinus christinae sp. nov. retains a complete female thoracic sternum, with well-preserved spermathecal apertures. These are the first of such structures known from the Necrocarcinidae; they are conspicuously large compared with similar structures in other palaeocorystoid families such as Cenomanocarcinidae and Palaeocorystidae and likely represent the more basal, plesiomorphic character state. In that respect, this new material contributes to a more complete knowledge of the morphology and diversity of the extinct palaeocorystoid stock.
Ranging from the Jurassic to the Pleistocene, the fossil record of decapod crustaceans in the British Isles is extensive, comprised of 159 species (including those in open nomenclature) assigned to 101 genera. Preservation is variable, but most taxa are based upon carapace material; the study of disarticulated limb elements has added surprisingly little to the known diversity. No new taxa are erected herein, but some species have been reassigned to more appropriate genera and/or families. The stratigraphic distribution of these crustaceans is such that most, if not all, species are known from the Mesozoic and Cenozoic successions of southern and eastern England. Some areas and horizons are particularly rich in decapod species, including the Aptian Atherfield Clay Formation, Isle of Wight; the Albian Gault Clay Formation; the Cenomanian Beer Head Limestone Formation, Wilmington Sands Member; the Lower Eocene London Clay Formation; the Paleogene of the Isle of Wight; and the various crag formations of East Anglia.
A small brachyuran crab, Archaeochiapasa mardoqueoi n. gen., n. sp., is reported from the lower Cenomanian (Upper Cretaceous) of the Sierra Madre Formation at El Chango Lagerstätte,Chiapas State, southeastern Mexico. Although it is decorticated and only the counterpart keeps a large part of the cuticle, the single male specimen exhibits an exceptional three-dimensional preservation that allows its description to be based not only on the dorsal carapace, both chelipeds and most walking legs, but also on remarkably conserved ventral structures: mxp3, thoracicsternum, and pleon. Archaeochiapasa mardoqueoi n. gen., n. sp. provides a morphological combination that does not conform to any previously known fossil brachyuran and furthermoreto any extant family. The high number of major differential characters suggest that Archaeochiapasa n. gen. must be included in the Eubrachyura Saint Laurent, 1980. A series of apomorphiessupports the erection of a new family for which we introduce the new name Archaeochiapasidae
n. fam.This fortunate discovery allows us to identify one of the earliest eubrachyurans with unique features, namely a very wide thoracic sternum displaying an unexpected structure for a lower Cenomanian representative, and a depressed, rimmed area (‘flange’) along the carapace postero- and postero-lateral margin. The new family is compared to the other fossil Eubrachyura known from the Early and mid-Cretaceous, which are very scarce and often incomplete, and to the more basal heterotreme Recent clades that are presently recognised on the basis of morphological, larval, spermatozoal and genetic data, e.g. the Dorippoidea MacLeay, 1838, and to the basal families of Majoidea Samouelle, 1819 (Oregoniidae Garth, 1958, Inachoididae Dana, 1851, and Inachidae MacLeay, 1838). A challenging hypothesis based on new interpretations is that the Late Jurassic Lecythocaridae Schweitzer & Feldmann, 2009 (in Glaessneropsoidea
Patrulius, 1959), only known by dorsal carapaces and formerly included in the Dromiacea DeHaan, 1833, could be related, with still obscure relationships, to the same lineage as the Archaeochiapasidae n. fam. The two families actually show striking similarities, such as the overallmorphology of carapace, a depressed area along the carapace posterior margin, and a bifurcate short rostrum. Therefore, we assume that, despite their Jurassic age, Lecythocaridae may well also be Eubrachyura, which brings the first “true crabs” or eubrachyurans (i.e., non-podotreme crabs) back to the Jurassic, contrary to the current opinions of paleontologists. The discovery of Archaeochiapasidae n. fam. raises a crucial question: the development of a very wide thoracic sternum in this old eubrachyuran. Is it the expression of an ancestral dispostion (plesiomorphy) or the result of an already existing evolutionary process of carcinisation (apomorphy)? And what is its phylogenetic significance?
A small brachyuran crab, Archaeochiapasa mardoqueoi n. gen., n. sp., is reported from the lower Cenomanian (Upper Cretaceous) of the Sierra Madre Formation at El Chango Lagerstätte, Chiapas State, southeastern Mexico. Although it is decorticated and only the counterpart keeps a large part of the cuticle, the single male specimen exhibits an exceptional three-dimensional preservation that allows its description to be based not only on the dorsal carapace, both chelipeds and most walking legs, but also on remarkably conserved ventral structures: mxp3, thoracic sternum, and pleon. Archaeochiapasa mardoqueoi n. gen., n. sp. provides a morphological combination that does not conform to any previously known fossil brachyuran and furthermore to any extant family. The high number of major differential characters suggest that Archaeochiapasa n. gen. must be included in the Eubrachyura Saint Laurent, 1980. A series of apomorphies supports the erection of a new family for which we introduce the new name Archaeochiapasidae n. fam. This fortunate discovery allows us to identify one of the earliest eubrachyurans with unique features, namely a very wide thoracic sternum displaying an unexpected structure for a lower Cenomanian representative, and a depressed, rimmed area (‘flange’) along the carapace postero- and postero-lateral margin. The new family is compared to the other fossil Eubrachyura known from the Early and mid-Cretaceous, which are very scarce and often incomplete, and to the more basal heterotreme Recent clades that are presently recognised on the basis of morphological, larval, spermatozoal and genetic data, e.g. the Dorippoidea MacLeay, 1838, and to the basal families of Majoidea Samouelle, 1819 (Oregoniidae Garth, 1958, Inachoididae Dana, 1851, and Inachidae MacLeay, 1838). A challenging hypothesis based on new interpretations is that the Late Jurassic Lecythocaridae Schweitzer & Feldmann, 2009 (in Glaessneropsoidea Patrulius, 1959), only known by dorsal carapaces and formerly included in the Dromiacea De Haan, 1833, could be related, with still obscure relationships, to the same lineage as the Archaeochiapasidae n. fam. The two families actually show striking similarities, such as the overall morphology of carapace, a depressed area along the carapace posterior margin, and a bifurcate short rostrum. Therefore, we assume that, despite their Jurassic age, Lecythocaridae may well also be Eubrachyura, which brings the first “true crabs” or eubrachyurans (i.e., non-podotreme crabs) back to the Jurassic, contrary to the current opinions of paleontologists. The discovery of Archaeochiapasidae n. fam. raises a crucial question: the development of a very wide thoracic sternum in this old eubrachyuran. Is it the expression of an ancestral dispostion (plesiomorphy) or the result of an already existing evolutionary process of carcinisation (apomorphy)? And what is its phylogenetic significance?
Based on numerous and remarkably preserved specimens from the Upper Creraceous, Cenomanian, at Lamnay and Le Mans (Sarthe), France, the fossil crab Lithophylax trigeri A. Milne-Edwards & Brocchi, 1879 is redescribed. Characters which were thought not to be easily fossilized (rostrum, vulvae, female and male abdomen, male pleopods, thoracic sternal sutures, stridulating apparatus and the reduced fifth pereopod) are present. It was possible by careful clearing of the fossil crab from the matrix to expose most of the parts, so that the structures could be studied almost as completely as in a recent species. Lithophylax trigeri is one of the most complete brachyuran crabs so far discovered from the Cenomanian, from the Cretaceous in general, and even more recently. The monotypic family Lithophylacidae Van Straelen, 1936 is redefined, and its relationships with the fossil and extant brachyuran families known from the Cretaceous, in particular the Carcineretidae Beurlen, 1930, Necrocarcinidae Förster, 1968, Hexapodidae Miers, 1886, Retroplumidae Gill, 1894, Palicidae Bouvier, 1897, and the Goneplacidae MacLeay, 1838, are discussed. © Publications Scientifiques du Muséum national d'Histoire naturelle.
Intensive bed-by-bed collecting in the type Maastrichtian area over the past ten years revealed important new paleobiological data on swimming crabs in the Late Cretaceous.
From the well-known upper Albian to lower Cenomanian (mid-Cretaceous) reefal limestones (Albeniz Unit) at Monte Orobe, northwest of Alsasua (Navarra, northern Spain), one new genus and species each of diogenid and porcellanid anomurans and one new genus of etyid brachyuran are described, on the basis of material contained in the VAN STRAELEN Collection at the Institut royal des Sciences naturelles de Belgique, Brussels. Annuntidiogenes ruizdegaonai n. gen., n. sp., which is closely related to the extant diogenid genus Aniculus DANA, 1852, represents the first paguroid carapace of Cretaceous age to be described and formally named. It compares well with an even better-preserved specimen from the Kunrade Limestone facies (Maastricht Formation; upper Maastrichtian) in southern Limburg, The Netherlands, here named Annuntidiogenes sunuciorum n. gen., n. sp. Annieporcellana dhondtae n. gen., n. sp. constitutes the oldest known member of the family Porcellanidae HAWORTH, 1825. Glyptodynomene inornata COLLINS, FRAAYE & JAGT, 1995 from the upper Maastrichtian of Maastricht (The Netherlands), originally interpreted as a dynomenid, is transferred to the Porcellanidae and reassigned to the genus Petrolisthes STIMPSON, 1858. The etyid crab Xanthosia fossa WRIGHT & COLLINS, 1972 is recorded for the first time from northern Spain. A new genus, Etyxanthosia n. gen., is erected to accommodate this, plus three North American species, X. aspera RATHBUN, 1935, X. pawpawensis SCHWEITZER HOPKINS, SALVA & FELDMANN, 1999 and X. reidi SCHWEITZER HOPKINS, SALVA & FELDMANN, 1999, all of late Albian age. A close phylogenetic relationship between E. fossa and the genera Glyptodynomene VAN STRAELEN, 1944 and Paranecrocarcinus VAN STRAELEN, 1936 is demonstrated. The two last-named are assigned to a new subfamily, Paranecrocarcininae n. subfam., which is characterised by enigmatic post-rostral slits.
A new species of Graptocarcinus is the stratigraphically youngest known member of the genus; it is here described together with a new species of the genus Caloxanthus from the late Maastrichtian of The Netherlands.
Description of two new species of the brachyuran genus Xanthosia Bell, 1863, from the upper Albian to Cenomanian Weno and Pawpaw formations from Tarrant County, Texas, increases the number of species in the genus to fifteen. Xanthosia has been recognized in England, the Netherlands, Madagascar, and in in the states of New Jersey, South Dakota, and Texas. The geologically oldest species from England gave rise to species from North America, Europe, and Madagascar. One group of species, with representatives from South Dakota, New Jersey, and Madagascar, may represent a separate taxon. The species 'Xanthosia' robertsi Secretan is herein removed from the genus and placed within the Portunidae, not the Xanthidae.