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Hessaster longimarginalis gen. et sp. nov. Isolated ossicles, Savigna 2a horizon. a Holotype (BMNH EE 13965), unpaired median sm in abactinal aspect. Unpaired median ims in actinal (b, c) and abactinal (d) views (EE 13966-68). g sm in abactinal view (EE
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The asteroid fauna from the Late Oxfordian marls (bifurcatus Zone, stenocycloides Subzone) of Savigna includes 11 taxa, distributed between 8 families, of which 1 (Plumasteridae) is new. A goniasterid of
distinctive morphology, Hessaster longimarginalis, is described as new, as is an asteriid, Savignasterias villieri. The material was recovered by...
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Fossils assigned to the predominantly deep-sea asteroid family Benthopectinidae Verrill, 1894 are described and their affinities reappraised. Detailed comparative morphology of ambulacrals, adambulacrals and marginal ossicles has revealed that only some extinct taxa fall within the morphological range of the modern representatives of the family. Th...
Euryalids, which include the spectacular basket stars, form a morphologically aberrant group of brittle stars. Surprisingly, the most recent molecular work found them to be sister to ophiurid brittle stars, thus challenging the traditional dichotomy between euryalids and non-euryalids, and leaving an enormous ghost lineage of more than 100 million...
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Understanding of the evolutionary history of the ophiuroids, or brittle stars, is hampered by a patchy knowledge of the fossil record. Especially, the stem members of the living clades are poorly known, resulting in blurry concepts of the early clade evolution and imprecise estimates of divergence ages. Here, we describe new ophiuroid fossil from t...
Citations
... The English specimens of Terminaster cancriformis studied here were found in the Oxford Clay, and lived in an epicontinental shallow sea, subject to disoxic to anoxic conditions (Belin & Kenig, 1994;Hudson & Martill, 1991). An almost complete albeit poorly preserved specimen of Terminaster cancriformis has been reported in the literature, from La Voulte-sur-Rhône (France) by Villier et al. (2009), and isolated ossicles were reported by Gale (2011aGale ( , 2011b from Savigna (France). Although the identification of isolated materials remains difficult, the material reported by Gale (2011aGale ( , 2011b can be safely attributed to the Zorocallida and was deposited in a shallow-water environment: ...
... An almost complete albeit poorly preserved specimen of Terminaster cancriformis has been reported in the literature, from La Voulte-sur-Rhône (France) by Villier et al. (2009), and isolated ossicles were reported by Gale (2011aGale ( , 2011b from Savigna (France). Although the identification of isolated materials remains difficult, the material reported by Gale (2011aGale ( , 2011b can be safely attributed to the Zorocallida and was deposited in a shallow-water environment: ...
... Our results on Zorocallida are difficult to reconcile with this hypothesis of the deep sea acting as refugees since the Jurassic, which would imply shallow marine taxa are derived rather than being plesiomorphic. Instead, the fossil record of Zorocallida is in accordance with the hypotheses stated by Gale (2011b): (1) Zorocallida were inhibiting shallow-water environments during the Mesozoic and migrated to bathyal and abyssal environments after the Palaeogene; or (2) Zorocallida were present in both shallow and deep-sea environments during the Mesozoic, but were removed from the shallow water during the Cenozoic. Gale (2011b) favoured the second hypothesis because of the specimen from La Voulte-sur-Rhône. ...
... Ophioderma spectabile and Dermocoma spp. have been shown to co-occur at depths of about 50-60 m (Gale 2011). It cannot be excluded that the differences between the Wapienno/Bielawy and Zalas localities (both relatively shallow-water and biohermal/biostromal in nature) are dictated by a somewhat different bathymetry and environmental energy, as well as palaeobiogeography, but those are hard to assess with any degree of certainty. ...
... The strata in Savigna consist mostly of thick calcareous mudstones interlayered with thinner marly limestones (Gale 2011). The type of sediment and fossil assemblages suggests a depth of deposition of about 50-60 m in a calm environment, far from the source of clastic material or biohermal buildups. ...
Ophiuroids from the Upper Jurassic marine deposits (upper Oxfordian–lower Kimmeridgian) of southern and north-western Poland have been studied in two sections: Zalas quarry in the Kraków-Częstochowa Upland in southern Poland and Wapienno/Bielawy quarries in the Kuyavia region of north-western Poland. Described herein are nine taxa belonging to five genera (one new to science): Alternacantha Thuy and Meyer, 2013; Dermocoma Hess, 1964; Ophiobartia Loba gen. nov.; Ophioderma Müller and Troschel, 1840; Ophiotreta Verrill, 1899, and three families: Ophiacanthidae and Ophiodermatidae (both of Ljungman, 1867), and Ophiotomidae Paterson, 1985. Only a few representatives of some of these taxa have previously been reported from the Jurassic of Poland. One species, Ophiobartia radwanskii Loba, is established as new. The ophiuroid material recognized from both Polish localities is close to those described from Western Europe at family or even genus level. Both studied ophiuroid assemblages from Zalas and Wapienno/Bielawy show similarities, being dominated by the cosmopolitan species Ophioderma spectabile Hess, 1966, and by different species of Dermocoma. The recognized ophiuroid assemblages represent a rather shallow-water environment.
... Our material bears a strong similarity to the specimens described by Gale (2011bGale ( , 2020, hence we tentatively assign it to the Astropectinidae. However, their pseudarchasterid affinities cannot be decisively excluded. ...
... It should be emphasised that Savigna represents quite a different palaeoecological setting than the Polish locality. Savigna strata are developed as thin beds of marly limestones separated from each other by thick beds of calcareous clays (Gale 2011b). The last ones contain rich asterozoan faunas. ...
A relatively rich assemblage of starfish is recognised from the talus facies of an Upper Jurassic (lower Kimmeridgian) biohermal, sponge-cyanobacterial build-up from the Wapienno/Bielawy succession exposed in a salt-dome anticline in Kuyavia region, north-central Poland. The paper presents 8 taxa belonging to 4 genera (one new to science): Boxaster gen. nov., Noviaster Valette, 1929, Tylasteria Valette, 1929, Valettaster Lambert, 1914, and 4 families: Astropectinidae Gray, 1840, Goniasteridae Forbes, 1841, Sphaerasteridae Schöndorf, 1906 and Stauranderasteridae Spencer, 1913. Only a very few representatives of some of these taxa have formerly been reported from the Jurassic of Poland. Two species are new: Valettaster planus sp. nov. and Boxaster wapienensis gen. et sp. nov. The Jurassic starfish assemblage recognised from the Wapienno/Bielawy succession is interpreted as an offshore starfish fauna with the admixture of allochtonous shallow-water taxa. The lithology of the source deposits indicates their transport by storm agitation and/or mass movements. This fact strongly influenced the preservation state, all collected plates being disarticulated and most of them abraded.
... Im Folgenden wird eine vorläufige Übersicht zu den in Buttenheim angetroffenen Echinodermen gegeben. Die Referenzen der im Text zitierten Taxon-Autoren können den Arbeiten von Gale (2011), Hess (1999, 2006, 2011, Thuy et al. (2011);Smith (2015Smith ( , 2016 und Waltschew (2000) entnommen werden. ...
... Im Folgenden wird eine vorläufige Übersicht zu den in Buttenheim angetroffenen Echinodermen gegeben. Die Referenzen der im Text zitierten Taxon-Autoren können den Arbeiten von Gale (2011), Hess (1999, 2006, 2011, Thuy et al. (2011);Smith (2015Smith ( , 2016 und Waltschew (2000) entnommen werden. ...
Crinoidea, Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea from the Early Jurassic (Pliensbachian) of Buttenheim, Franconia, Bavaria, Germany.
... Order Spinulosida Perrier, 1884 Plumasteridae Gale, 2011Genus Plumaster Wright, 1863 Plumaster sp. Asteroids from the Lias Group have, until recently, received little attention since the monograph by Thomas Wright (1862-1880. ...
... They are concavo-convex in shape with typically 7 or 8 tubercles externally, and articulate with successive plates via a prominent flange bearing a row of 7 or 8 interlocking grooves and ridges. On the basis of these features these remains can be assigned to the genus Plumaster, a multirayed starfish with from 12 to 22 arms that hitherto was known only from the Pliensbachian to Oxfordian stages (Thuy et al., 2011;Gale, 2011). The numbers of tubercles and grooves on the Glenarm specimens is greater than for either of the Plumaster species recently described, by Thuy et al. (2011) from the Pliensbachian and by Gale (2011) from the Oxfordian, but it is comparable with that of the type species, Plumaster ophiuroides Wright, 1863, from the Pliensbachian, as figured by Gale (2011). ...
... On the basis of these features these remains can be assigned to the genus Plumaster, a multirayed starfish with from 12 to 22 arms that hitherto was known only from the Pliensbachian to Oxfordian stages (Thuy et al., 2011;Gale, 2011). The numbers of tubercles and grooves on the Glenarm specimens is greater than for either of the Plumaster species recently described, by Thuy et al. (2011) from the Pliensbachian and by Gale (2011) from the Oxfordian, but it is comparable with that of the type species, Plumaster ophiuroides Wright, 1863, from the Pliensbachian, as figured by Gale (2011). Preservation of the Glenarm material does not allow assignment to a particular species but these specimens do represent a significant downward extension of the stratigraphic range of the genus. ...
An overview is provided of fossil echinoderm taxa recovered from the Jurassic (Lias Group) and Triassic (Penarth Group) of Ireland. Despite limited outcrop and generally poor exposure, at least 12 species are recorded (6 crinoids, 2 echinoids, 3 ophiuroids and one asteroid), with significant new material recovered from an early Hettangian lagerstätte. The crinoid Isocrinus angulatus (Fraas, 1858), omitted from an earlier Palaeontographical Society Monograph on Lower Jurassic crinoids, is described based on articulated material.
... Spencer, 1913;Rasmussen, 1950;Müller, 1961;Blake, 1972Blake, , 1976Blake, , 1978Gale, 1987;Breton, 1992;Breton & Ferré, 1995). The morphology of the ossicles has been found to be consistent and taxonomic identification of isolated ossicles are now commons (Hess, 1974;Villier, 1999Villier, , 2008Breton & Néraudeau, 2008;Gale, 2011a). The use of ossicle anatomy for taxonomic purposes requires a precise understanding of the asteroid skeleton and comparative anatomy of the ossicles. ...
... The species was originally described by Quenstedt (1876) (Hess, 1974;p.657). Later, additional material was described as Terminaster cancriformis (Gale, 2011a;Gale, 2011b (Hess, 1974;Villier et al., 2009). The interpreted subambulacral spine are instead poorly preserved straight pedicellariae ( Fig. 4.11B). ...
... The reappraisal of ten extinct forcipulatacean taxa from the Jurassic and the Cretaceous permits performing the most comprehensive phylogenetic analysis based on morphological pustules on its actinals and inferomarginals (Gale, 2011a). Keyhole pustules on actinals and inferomarginals are present in both the Stichasteridae and the Asteriidae . ...
Forcipulatacea is one of the main clades of extant Asteroidea (also called sea stars or starfish), with approximately 400 described extant species, but a relatively sparse fossil record. Recent research demonstrated that phylogenetically informative morphological characters can successfully be defined in echinoderms from the comparative analysis of skeletal elements (ossicles), using ossicle shape, articulations among ossicles, and marks left behind by soft tissues. This allows for the joint analysis of extant and extinct taxa. The first chapter of this thesis describes the post-metamorphic ontogeny of the forcipulatacean species Zoroaster fulgens. The study of this ontogenetic series allows for the description of new morphological characters and a better understanding of the homology of ossicle structures found in the ossicles of Z. fulgens in particular, and other forcipulatacean sea stars in general (i.e. muscle insertions and articulation areas). The second chapter describes the anatomy of 29 extant forcipulatacean asteroids, followed by the definition of 115 morphological characters, resulting in the largest character/taxon matrix assembled to date for Forcipulatacea. Subsequent phylogenetic analysis recovers the main groups as monophyletic: Asteriidae, Brisingida, Stichasteridae, and Zoroasteridae. Morphological synapomorphies are proposed for these clades and homologies and convergences between different clades are discussed. The last two chapters focus on the study of Mesozoic forcipulataceans. Five Jurassic and one Cretaceous taxon are reappraised and new anatomical observations with emended diagnoses are provided for four others. The phylogenetic position of these fossils is investigated using the character/taxon matrix from chapter 2. The reanalysis of these fossils permits performing the most comprehensive phylogenetic analysis based on morphological data for this group to date. The results suggest an early diversification of the Forcipulatacea, during the Jurassic. Mesozoic forcipulataceans exhibit a unique combination of characters that distinguish them from extant taxa. The early diversity of the Forcipulatacea was greater than previously thought and challenges existing perceptions of the evolutional history of this major clade.
... Ambulacrals and adambulacrals alternate, and the adambulacrals are slanted laterally and distally. The adambulacrals comprise two parts; a thicker adradial region and a narrow, parallel sided elongated adambulacral extension as in Savignaster wardi (Gale 2011a(Gale , 2011b. The adradial portions are thickened where spine bases were present. ...
... The specimens consist of individuals which have split horizontally approximately along the plane of the ambitus, an unusual preservation mode. The presence of interradial chevron ossicles permit placement of the new species in the clade including Korethrasteridae and Pterasteridae (Gale 2011a(Gale , 2011b. It can furthermore be assigned to Savignaster based on the similarity of the shape (long adambulacral extensions) of the adambulacrals to those of S. wardi Gale, 2011. ...
... nov. Savignaster was identified by Gale (2011aGale ( , 2011b) as a basal pterasterid, which possesses most, but not all of the synapomorphies of extant members of the family. Savignaster is known from the Bathonian of Kutch, India (A.S. ...
The Late Jurassic–Early Cretaceous Slottsmøya Member of the Agardhfjellet Formation in central Spitsbergen has yielded two new species of asteroids and two species of ophiuroids, one of which is described as new. Polarasterias janusensis Rousseau & Gale gen. et sp. nov. is a forcipulatid neoasteroid with elongated arms, small disc and very broad ambulacral grooves with narrow adambulacrals. Savignaster septemtrionalis Rousseau & Gale sp. nov. is a pterasterid with well-developed interradial chevrons. The Spitsbergen specimens are the first described articulated material of Savignaster and reveal the overall arrangement of the ambulacral groove ossicles. Ophiogaleus sp. is an ophiacanthid with relatively long jaws and lateral arm plates, with a coarsely reticulate outer surface. Here again, we report the first articulated skeletons of this genus, providing unprecedented insights into the disc morphology. Ophioculina hoybergia Rousseau & Thuy gen. et sp. nov. is an ophiopyrgid with a well-developed arm comb and tentacle pores reduced to within-plate perforations starting at median arm segments. These new finds are important additions to the asterozoan fossil record with regard to their good degree of articulation and the high latitudinal position of the localities. They significantly add to the set of exhaustively known fossil asterozoan taxa which play a key role in the phylogenetic analysis and reconstruction of evolutionary history.
... First, these tubercles commonly coalesce locally to form irregular ridges and are rarely arranged in an apparently regular pattern (e.g. Villier et al. 2004;Villier 2008;Gale 2011). Furthermore, although some seem to be comprised of thin imperforate stereom, internally they are typically porous and do not exhibit a characteristic lens-like structure (Figs. ...
Echinoderms are characterized by a calcite endoskeleton with a unique microstructure, which is optimized for multiple functions. For instance, some light-sensitive ophiuroids (Ophiuroidea) and asteroids (Asteroidea) possess skeletal plates with multi-lens arrays that are thought to act as photosensory organs. The origins of these lens-like microstructures have long been unclear. It was recently proposed that the complex photosensory systems in certain modern ophiuroids and asteroids could be traced back to at least the Late Cretaceous (ca. 79 Ma). Here, we document similar structures in ophiuroids and asteroids from the Early Cretaceous of Poland (ca. 136 Ma) that are approximately 57 million years older than the oldest asterozoans with lens-like microstructures described thus far. We use scanning electron microscopy, synchrotron tomography, and electron backscatter diffraction combined with focused ion beam microscopy to describe the morphology and crystallography of these structures in exceptional detail. The results indicate that, similar to Recent light-sensitive ophiuroids, putative microlenses in Cretaceous ophiuroids and asteroids exhibit a shape and crystal orientation that would have minimized spherical aberration and birefringence. We suggest that these lens-like microstructures evolved by secondary deposition of calcite on pre-existing porous tubercles that were already present in ancestral Jurassic forms.
... The Jurassic Terminaster cancriformis is difficult to classify. Authors do not consistently homologize the two lateral rows of plates on each side of the arms: they are interpreted either as one row of inferomarginal and one row of actinolateral plates (Hess 1974;Mah 2007), or as two rows of marginal plates (Villier et al. 2009;Gale 2011b). With a single row of marginal plates, Terminaster is close to Zoroasteridae, and could even nest within this family as sister group to an abyssal clade (Mah 2007). ...
We describe Superstesaster promissor gen. et sp. nov., a starfish from the Smithian (Early Triassic) of Utah (USA) that fills a major gap in the fossil record of the Asteroidea. The post-Palaeozoic crown group Asteroidea are distinct from any of the diverse Palaeozoic forms. However, current understanding of the Palaeozoic–Mesozoic transition is blurred by a large gap in the fossil record between the Early Permian and the Middle Triassic. Building on the newly described taxon, a phylogenetic analysis investigates the relationships between Palaeozoic and Mesozoic Asteroidea. Including 30 species and 70 morphological characters, it is the most comprehensive phylogeny produced for fossil starfishes so far. Relationships among Palaeozoic forms remain poorly resolved, but their position in the tree is grossly consistent with stratigraphy. The tree topology implies the appearance of a wide range of morphologies during the Ordovician, a bottleneck during the end-Devonian events, and a second diversification during the Carboniferous, before a diversity decline at the end of the Permian. Superstesaster promissor nests above Palaeozoic taxa and appears as the sister group to the post-Palaeozoic Asteroidea. It represents the first record of a member of the stem group in the Mesozoic, and it likely reflects the ancestral morphology of the crown group. S. promissor shares with the crown group typical ambulacral and adambulacral plate shape and articulation. Phylogenetic relationships within the crown group remain poorly resolved, although three clades are consistent with molecular and morphological phylogenies available for extant forms: Valvatacea (Comptoniaster, Pentasteria, Advenaster, Noviaster), Forcipulatacea (Germanasterias, Argoviaster) and Velatida (Tropidaster, Protremaster). A Triassic and Jurassic radiation of the crown group is confirmed. Most Triassic and Jurassic forms do not share all synapomorphies with extant clades and usually represent separate clades or stem members of modern clades rather than true members of modern families.
http://zoobank.org/urn:lsid:zoobank.org:pub:8CAC421A-DC0C-4EEB-B872-C7505FA8C2EA
... Kroh, 2004;Thuy et al., 2014), asteroids (e.g. Gale, 2011) and holothurians (e.g. Reich and Ansorge, 2014) and has been used to bolster datasets in a number of macroevolutionary studies involving echinoderms (e.g. ...
Articulated echinoids are rare in Palaeozoic strata. In order to gain a better understanding of palaeodiversity and community composition, it is more than useful to incorporate disarticulated specimens into estimates of such metrics. It has been demonstrated that disarticulated ossicles of echinoids from the post-Palaeozoic can be diagnostic at the species level and can be used to bolster analyses of diversity. Although usually not identifiable to the species level, many families, and some genera, of Palaeozoic echinoids have diagnostic properties that can be recognized from disarticulated plates. Herein, it is demonstrated that such diagnostic properties exist for plates of the Palaechinidae, Archaeocidaridae and Proterocidaridae, and that the utility of using disarticulated echinoid ossicles to aid in palaeodiversity studies extends back into the Palaeozoic. Portions of the echinoid fauna from Tournai, Belgium, are revised and disarticulated plates of echinoids from two upper Tournaisian localities in Belgium, Pair and Petit-Modave, are examined and described. The fauna of Pair yielded an indeterminate palaechinid and Hyattechinus sp., while the fauna from Petit-Modave yielded only indeterminate palaechinid plates. Although no articulated specimens are known from these localities, when disarticulated plates are taken into account, a more accurate estimate of palaeodiversity becomes clear. Copyright
