[Paleontology • 2025] Paradoxophidion richardoweni • A New peculiar early diverging caenophidian Snake (Serpentes) from the late Eocene of Hordle Cliff, England

 

 Paradoxophidion richardoweni 

 Georgalis & Jones, 2025

  sciencepress.mnhn.fr 

  x.com/DrGeorgalis

 Artwork by Jaime Chirinos.

We here describe a new genus and species of snake, based on several trunk and caudal vertebrae, originating from the late Eocene (MP 17a) of Hordle Cliff, England. We investigated the fossil ­material via both visual microscopy and micro-computed tomography (μCT) scanning, focused on its intracolumnar variation, and extensively compared it with other Paleogene snake taxa from England and continental Europe. The new small taxon is characterized by an array of bizarre and distinctive vertebral features that can differentiate it from all other snakes. Its morphology is similar to that of russellophiids; however, some anatomical features differ drastically from those observed in the latter group and therefore, defy such family-level placement. In addition, the new English taxon bears some striking resemblance with extant acrochordids, particularly with the species Acrochordus granulatus (Schneider, 1799). Accordingly, we consider that the new taxon most likely represents an early diverging caenophidian, potentially being even a member of Acrochordidae Bonaparte, 1831, far outside the so far known stratigraphic and geographic distribution of the latter group. It further adds to the astonishing diversity of vertebral morphologies of European Paleogene snakes.

Keywords: Squamata, Caenophidia, Russellophiidae, Acrochordidae, vertebral morphology, new genus, new species

Holotype trunk vertebra NHMUK PV R 10795 of Paradoxophidion richardoweni n. gen., n. sp. in anterior (A), posterior (B), left lateral (C), dorsal (D), and ventral (E) views. Scale bar: 1 mm.

 Paradoxophidion richardoweni n. gen., n. sp.

Hypothetical life reconstruction of  Paradoxophidion richardoweni n. gen., n. sp. 

 Artwork by Jaime Chirinos.

 

Georgios L. GEORGALIS and Marc E. H. JONES. A New peculiar early diverging caenophidian Snake (Serpentes) from the late Eocene of Hordle Cliff, England. Comptes Rendus Palevol. 24 (25); 505-530. https://sciencepress.mnhn.fr/en/periodiques/comptes-rendus-palevol/24/25  [07 November 2025] 

 Researchgate.net/publication/397396177_A_new_peculiar_early_diverging_caenophidian_snake_Serpentes_from_the_late_Eocene_of_Hordle_Cliff_England

 x.com/DrGeorgalis/status/1986823858922336696

[Paleontology • 2025] Istiorachis macarthurae • The Origins of Neural Spine Elongation in iguanodontian dinosaurs and the Osteology of A New sail-back styracosternan (Ornithischia: Iguanodontia) from the Lower Cretaceous Wealden Group of England

Istiorachis macarthurae  

Lockwood, Martill & Maidment, 2025 

 

DOI: doi.org/10.1002/spp2.70034 

Original artwork by James Brown.

Abstract

The Wealden Group of southern England was deposited during the late Berriasian to early Aptian interval. It records a critical time in the development of iguanodontian dinosaur diversity, which increased from low levels during the Jurassic to higher levels in the Aptian and Albian. A new iguanodontian dinosaur, Istiorachis macarthurae gen. et sp. nov. from the Wessex Formation (Wealden Group) of the Isle of Wight, exhibits hyperelongation of the dorsal and caudal neural spines, suggesting that it possessed a possible sail structure. Ancestral state reconstruction for the relative height of dorsal neural spines in iguanodontians demonstrates that modest elongation began with Ankylopollexia in the Late Jurassic and elongation became established during the Berriasian stage of the Early Cretaceous, albeit with widely disparate values. Hyperelongation of neural spines occurred more sporadically throughout the Cretaceous, being recorded most often in the Barremian and early Aptian. Possible explanations for neural spine elongation in Ankylopollexia include biomechanical advantage, perhaps related to greater mass and a locomotory shift towards quadrupedalism, and visual signalling driven either by sexual selection or species recognition, or both. The function of elongate neural spines was probably pluralistic and differed in different taxa. No single explanation fully supports the variation seen throughout the Cretaceous.

Keywords: Iguanodontia, diversity, sexual signalling, Isle of Wight, ossified tendons, Barremian

SYSTEMATIC PALAEONTOLOGY

DINOSAURIA Owen 1842

ORNITHISCHIA Seeley 1888

ORNITHOPODA Marsh 1881

IGUANODONTIA Baur 1891

ANKYLOPOLLEXIA Sereno 1986

STYRACOSTERNA Sereno 1986

Genus Istiorachis nov.

Derivation of name: The name is derived from the Ancient Greek words ἱστίον (istion), meaning a sail, and ῥάχις (rachis), the spine or backbone. It refers to the probable sail-back appearance of the dinosaur.

Istiorachis macarthurae sp. nov.

 

Derivation of name: The species name honours Dame Ellen MacArthur, an English sailor who in 2005 set a world record for the fastest solo non-stop voyage around the world on her first attempt and who also founded the Ellen MacArthur Cancer Trust for young people on the Isle of Wight.

Holotype: MIWG 6643 is a partial skeleton composed of the following elements: one cervical vertebra, eight dorsal vertebrae, three dorsal rib heads, a partial sacrum, seven caudal vertebrae, both pubes and both ischia.

Location & horizon: MIWG 6643 was excavated by the late Mr Nicholas Chase from the ‘Black Band’ (bed L11 in Stewart 1978), a plant debris bed cropping out c. 100 m east of Grange Chine, lying above the Grange Chine Sandstone in the Wessex Formation. The site is a c. 1.5-m-thick bed that has occasionally yielded dinosaur remains, including IWCMS 1997.550, the holotype specimen of the tyrannosauroid theropod Eotyrannus lengi (Hutt et al. 2001; Naish & Cau 2022). Unfortunately the excavation site was poached and an unknown amount of the skeleton was taken before collection could be completed.

Diagnosis: Istiorachis macarthurae differs from all other iguanodontians by possessing one autapomorphy, namely two anterior parasagittal tuberosities present on the ventral surface of a posterior dorsal vertebra, marking a change from vertebrae with a ventral keel to a flat surface. A posterior cervical vertebra has a damaged anteroventral process at the base of the neural spine, potentially representing a second autapomorphy. Istiorachis macarthurae also possesses the following features, which, although not unique to the taxon, occur in a unique character combination. An interpostzygapophyseal fossa and tubular cavity is located between the origin of the postzygapophyses and above the neural canal: a similar fossa is also seen in ...

Istiorachis macarthurae gen. et sp. nov. (MIWG 6643). Life restoration.
Original artwork by James Brown.

Istiorachis macarthurae gen. et sp. nov. holotype (MIWG 6643).
Skeletal reconstruction. Scale bar represents 500 mm.

 

Jeremy A. F. Lockwood, David M. Martill and Susannah C. R. Maidment. 2025.  The Origins of Neural Spine Elongation in iguanodontian dinosaurs and the Osteology of A New sail-back styracosternan (Dinosauria, Ornithischia) from the Lower Cretaceous Wealden Group of England. Papers in Palaeontology. DOI: doi.org/10.1002/spp2.70034 [21 August 2025]

[PaleoIchthyology • 2025] Pararhincodon torquis • Three-dimensional Fossils of a Cretaceous Collared Carpet Shark (Orectolobiformes: Parascylliidae) shed light on Skeletal Evolution in galeomorphs

 

 Pararhincodon torquis

Dearden, Johanson, O’Neill, Miles, Bernard, Clark, Underwood & Rücklin, 2025

 DOI: doi.org/10.1098/rsos.242011 

Artwork by Julio Lacerda

 

Abstract

A rich fossil record of teeth shows that many living shark families’ origins lie deep in the Mesozoic. Skeletal fossils of the sharks to whom these teeth belonged are far rarer and when they are preserved are often flattened, hindering understanding of the evolutionary radiation of living shark groups. Here we use computed tomography to describe two articulated Upper Cretaceous shark skeletons from the Chalk of the UK preserving three-dimensional neurocrania, visceral cartilages, pectoral skeletons and vertebrae. These fossils display skeletal anatomies characteristic of the Parascylliidae, a family of Orectolobiformes now endemic to Australia and the Indo Pacific. However, they differ in having a more heavily mineralized braincase and a tri-basal pectoral fin endoskeleton, while their teeth can be attributed to a new species of the problematic taxon Pararhincodon. Phylogenetic analysis of these new fossils confirms that Pararhincodon is a stem-group parascylliid, providing insight into the evolution of parascylliids’ distinctive anatomy during the late Mesozoic–Cenozoic shift in orectolobiform biodiversity from the Northern Atlantic to the Indo Pacific. Meanwhile both Pararhincodon and extant parascylliids have a distinctive vertebral morphology previously described only in Carcharhiniformes, contributing a skeletal perspective to the picture emerging from macroevolutionary analyses of coastal, small-bodied origins for galeomorphs.

Keywords: Elasmobranchii, Orectolobiformes, Galeomorphii, CT scanning, Cretaceous

 

Class. Chondrichthyes Huxley, 1880

Subclass. Elasmobranchii Bonaparte, 1838

Superorder. Galeomorphii Compagno, 1973

Order. Orectolobiformes Applegate, 1972

Family. Parascylliidae Gill, 1862

Genus: Pararhincodon Herman in Cappetta, 1976

  Pararhincodon torquis n. sp.

Holotype specimen: NHMUK PV P 73821 a

Diagnosis of species: Very small, strongly asymmetrical teeth. Cusp triangular with sharp cutting edge, strongly bent lingually and distally. Lateral cusplet on distal edge of tooth, absent on mesial edge which is developed into slight shoulder. Base of cusp has a labial bulge and the medial section is developed into a low labial protuberance. Parallel folds present at the base of the cusp, some of which travel up the cusp’s face. Root flat and developed into mesial and distal lobes with deep, open nutrient groove.

 

Derivation of name: From torc, a metal collar associated with cultures from the European Iron Age.

Richard P. Dearden, Zerina Johanson, Helen L. O’Neill, Kieran Miles, Emma L. Bernard, Brett Clark, Charlie J. Underwood and Martin Rücklin. 2025. Three-dimensional Fossils of a Cretaceous Collared Carpet Shark (Parascylliidae, Orectolobiformes) shed light on Skeletal Evolution in galeomorphs. R. Soc. Open Sci. 12: 242011. DOI: doi.org/10.1098/rsos.242011 [30 April 2025]

 

  

[Paleontology • 2024] Theropod Dinosaur Diversity of the lower English Wealden: Analysis of a tooth-based fauna from the Wadhurst Clay Formation (Lower Cretaceous: Valanginian) via phylogenetic, discriminant and machine learning methods

An Early Cretaceous floodplain in southeastern England, 135 million years ago:
a spinosaur takes over the carcass of an ornithopod, much to the annoyance of the smaller tyrannosaurs (left) and dromaeosaurids.

in Barker, Handford, Naish, Wills, Hendrickx, ... et Gostling, 2024. 

DOI: doi.org/10.1002/spp2.1604

artwork by Anthony Hutchings.

 

Abstract

The Lower Cretaceous Wealden Supergroup of southern England yields a diverse assemblage of theropod dinosaurs, its taxa being represented by fragments in addition to some of the most informative associated skeletons of the European Mesozoic. Spinosaurids, neovenatorid allosauroids, tyrannosauroids and dromaeosaurids are among reported Wealden Supergroup clades. However, the majority of relevant specimens are from the Barremian Upper Weald Clay and Wessex formations, and theropod diversity in the older Berriasian–Valanginian Hastings Group has remained poorly known, the fragmentary specimens reported thus far remaining enigmatic both in terms of phylogenetic affinities and sometimes provenance. A better understanding would be welcome given the paucity of Berriasian–Valanginian dinosaurs worldwide. Here, we describe an assemblage of Hastings Group theropod teeth from the Valanginian Wadhurst Clay Formation, mostly collected from the Ashdown Brickworks locality near Bexhill, East Sussex. These teeth were assessed using phylogenetic, discriminant and machine learning analyses and were found to include members of Spinosauridae, Tyrannosauroidea and Dromaeosauridae, in addition to others that remain of uncertain affinity within Coelurosauria. The taxa appear distinct from those already known from Wealden Supergroup strata: the spinosaurid cannot be referred to Baryonyx or the tyrannosauroid to Eotyrannus, for example, but we have not named new taxa at this time. Combined with other findings in the Wadhurst Clay Formation, our study indicates that Valanginian theropod diversity was comparable to that of younger Wealden Supergroup units, implying that the ‘characteristic’ theropod components of Wealden faunas were established early in the deposition of this famous geological succession.

Keywords: theropod, Wealden Supergroup, phylogenetics, machine learning, dinosaur, Cretaceous

Theropod teeth from the Wadhurst Clay Formation.
A, BEXHM 1995.485 (morphotype I). B, BEXHM 2002.50.123 (morphotype II). C, BEXHM 2002.50.124 (morphotype III). D, BEXHM 2005.29 (morphotype IV). E, NHMUK PV R37630 (morphotype V).

 A, C–E, lingual; B, labial view. Scale bar represents 10 mm.

Schematic representation of the theropod diversity throughout the Wealden Supergroup, with specimens from the Wealden Group (Wessex sub-basin) and the Hastings and Weald Clay groups (Weald sub-basin).

DOI: doi.org/10.1002/spp2.1604

An Early Cretaceous floodplain in southeastern England, 135 million years ago: a spinosaur (centre) takes over the carcass of an ornithopod, much to the annoyance of the smaller tyrannosaurs (left) and dromaeosaurids (bottom right).

artwork by Anthony Hutchings.

Chris T. Barker, Lucy Handford, Darren Naish, Simon Wills, Christophe Hendrickx, Phil Hadland, Dave Brockhurst and Neil J. Gostling. 2024. Theropod Dinosaur Diversity of the lower English Wealden: Analysis of a tooth-based fauna from the Wadhurst Clay Formation (Lower Cretaceous: Valanginian) via phylogenetic, discriminant and machine learning methods. Papers in Palaeontology. DOI: doi.org/10.1002/spp2.1604

[Paleontology • 2024] Threordatoth chasmatos • A new procolophonid (Parareptilia: Procolophonidae)with complex dentition from the Late Triassic of southwest England

Threordatoth chasmatos

Meade, Butler, Jones & Fraser, 2024 

 

DOI: doi.org/10.1002/spp2.1605 

Artwork by Mark Witton.

Abstract

Fissure fill deposits from the Late Triassic to Early Jurassic of England and Wales preserve a diverse small tetrapod fauna including procolophonids, an important group of Permian and Triassic parareptiles that radiated across Pangaea following the end-Permian extinction event. Procolophonids are currently known from two fissure fill sites: incomplete and isolated remains from Ruthin Quarry (Wales) and type and referred material of Hwiccewyrm trispiculum from Cromhall Quarry (southwest England). The age of the Cromhall fissure deposits has been debated but recent radiometric dating suggests a Carnian age for at least some of the fossil assemblages. Here, we present material from several fissure assemblages at Cromhall, which are interpreted as stratigraphically older than the assemblage that yielded Hwiccewyrm. We describe a new species of leptopleuronine procolophonid based on partial remains with unique tooth morphology. Threordatoth chasmatos gen. et sp. nov. is characterized by maxillae with a reduced number of complex tricuspid teeth along with dentaries that bear labiolingually compressed monocuspid teeth and in some cases have a peculiar edentulous tip. These distinct tooth morphologies occlude closely, perhaps facilitated by a flexible dentary symphyseal connection. This unique combination of characters may suggest a high degree of oral food processing of a mode unlike other procolophonids, occurring among the broader leptopleuronine adaptation towards diets of high-fibre herbivory/omnivory and insectivory. Phylogenetic analysis places the remains of Threordatoth as a derived leptopleuronine, sister taxon to Hwiccewyrm, in a clade with taxa including Soturnia, Hypsognathus, Libognathus and two unnamed leptopleuronines from the southwest USA.

Keywords: Procolophonidae, fissure fill, Late Triassic, Leptopleuroninae, Parareptilia, dental complexity

SYSTEMATIC PALAEONTOLOGY

PARAREPTILIA Olson, 1947 sensu Laurin & Reisz (1995)

PROCOLOPHONOIDEA Romer, 1956

PROCOLOPHONIDAE Seeley, 1888

LEPTOPLEURONINAE Ivakhnenko, 1979

Threordatoth chasmatos gen. et sp. nov. UMZC 2023.122 (holotype), partial left maxilla with four teeth in:
 A, lateral; B, medial; C, ventral; D, dorsal view.

Genus Threordatoth nov.

 

Derivation of name: The genus name is derived from Old English and recognizes the tricuspid nature of the maxillary teeth of this taxon: þrēo meaning ‘three’ (undeclined) in the Mercian dialect; orda meaning ‘points’, or ‘spear points’; and tōþ meaning ‘tooth’.

 

Threordatoth chasmatos sp. nov.

Derivation of name: The species name is derived from Greek: χάσμα meaning ‘yawning chasm’, or ‘fissure’, referring to the fissures in which Threordatoth and numerous other taxa are preserved.

Diagnosis Distinguished from other procolophonids by the following combination of features: low maxillary tooth count (three or four); maxillary crowns are triangular in occlusal view, being strongly mesiodistally expanded at the labial margin (best developed in tooth 2); distal margins of the maxillary crowns are concave in occlusal view; maxillary crowns are tricuspid, with two clearly separated labial cusps; distolabial cusp of maxillary crowns is enlarged relative to mesiolabial cusp; two foramina on lateral surface of the maxilla, the anterior foramen being larger and positioned at the mid-height of the maxilla above the mesiolabial cusp of the second maxillary tooth, and the posterior foramen being positioned above the space between the second and third maxillary teeth and closer to the ventral margin.

Life reconstruction of Threordatoth chasmatos gen. et sp. nov. among the fissures of Carnian–Norian southwest England, based in part upon aspects of the anatomy of the closely related Hwiccewyrm.

Artwork by Mark Witton.

Luke E. Meade, Richard J. Butler, Marc E. H. Jones and Nicholas C. Fraser. 2024. A new procolophonid with complex dentition from the Late Triassic of southwest England. Papers in Palaeontology

DOI: doi.org/10.1002/spp2.1605 

  x.com/ThePalAss/status/1865009467596628266

[Paleontology • 2024] Comptonatus chasei • A New iguanodontian Dinosaur (Iguanodontia: Hadrosauriformes) from the Lower Cretaceous Wessex Formation of the Isle of Wight, southern England

Comptonatus chasei

Lockwood, Martill & Maidment, 2024

DOI: 10.1080/14772019.2024.2346573

 artwork by John Sibbick.

 

Abstract

A new iguanodontian dinosaur, Comptonatus chasei gen. et sp. nov., is described from the Lower Cretaceous Wessex Formation of the Isle of Wight. These strata provide an important record of a critical time in the development of iguanodontian diversity. The specimen, which is described here for the first time, was found and excavated in 2013 and represents the most complete iguanodontian skeleton discovered in the Wealden Group for a century. A new taxon is diagnosed by several autapomorphies found in the neurocranium, teeth, coracoid and other parts of the body, together with a unique suite of characters. These include a dentary with a straight ventral border, and a markedly expanded prepubic blade. These features set it apart from the sympatric Mantellisaurus atherfieldensis, Brighstoneus simmondsi and Iguanodon cf. bernissartensis, increasing the known diversity of this clade in the Barremian–early Aptian of England.  

Keywords: Barremian, Wealden Group, supraoccipitalvomer, diversity

Systematic palaeontology

Dinosauria Owen, 1842

Ornithischia Seeley, 1887

Ornithopoda Marsh, 1881

Iguanodontia Baur, 1891

Ankylopollexia Sereno, 1986

Styracosterna Sereno, 1986

Hadrosauriformes Sereno, 1997

Comptonatus gen. nov.

Etymology: Comptonatus (‘the Compton thunderer’) is a contraction of the words ‘Compton’ on the Isle of Wight and ‘tonatus’, the Latin for thundered, and reflects the place of discovery and the large size of the animal.

Location and horizon: The Wessex Formation, ‘middle’ Barremian, Lower Cretaceous. IWCMS 2014.80 was excavated during September–October 2013, from a plant debris bed on National Trust property to the west of the fault in Compton Bay, and close (c. 50 m) to where IWCMS 2013.175, a skeleton of Valdosaurus canaliculatus Galton, Citation1977 (Barrett, Citation2016) was excavated the previous year. The excavation was conducted under the supervision of Dinosaur Isle Museum (IWCMS) and site records and drawings were collected by Mr Stephen Hutt, the then curator. The site exposes a deep (c. 3 m) plant debris bed that occasionally yields articulated dinosaur remains, but frequently produces the trunks of large conifers, usually attributed to Pseudofrenelopsis parceramosa (Francis, Citation1987). Other vertebrate remains uncovered from the excavation site include ganoid fish scales (cf. Scheenstia sp.), an indeterminate crocodilian tooth and several very large, but fragmentary iguanodontian remains, including three pedal phalanges, a neural arch, and some rib sections.

 Comptonatus chasei gen. et sp. nov. (IWCMS 2014.80).
Preliminary reconstruction of the skull. Shaded areas represent material present in the holotype.

Abbreviations: d, dentary; f, frontal; m, maxilla; n, nasal; nc, neurocranium; orb, orbit; p, parietal; pa, paroccipital process; pf, prefrontal; po, postorbital; q, quadrate, s, surangular; sq, squamosal. Scale bar represents 100 mm.

 Comptonatus chasei gen. et sp. nov. (IWCMS 2014.80). Life restoration.

Original artwork by John Sibbick.

Comptonatus chasei gen. et sp. nov.

Etymology: The specific name honours the late Mr Nick Chase, winner of the Palaeontological Association’s Mary Anning Award in 2018, who made the initial discovery and through his lifetime contributed enormously to the collections at Dinosaur Isle Museum, Isle of Wight, and the Natural History Museum, London (Lockwood et al., Citation2019).

 

Jeremy A. F. Lockwood, David M. Martill and Susannah C. R. Maidment. 2024. Comptonatus chasei, A New iguanodontian Dinosaur from the Lower Cretaceous Wessex Formation of the Isle of Wight, southern England. Journal of Systematic Palaeontology. 22(1); 2346573. DOI: doi.org/10.1080/14772019.2024.2346573

 www.port.ac.uk/news-events-and-blogs/news/research-reveals-the-most-complete-dinosaur-discovered-in-the-uk-in-a-century

[PaleoIchthyology • 2023] An enigmatic large mawsoniid coelacanth (Sarcopterygii: Actinistia) from the Upper Jurassic Kimmeridge Clay Formation of England

  Mawsoniidae gen. et sp. indet. (MJML K785).

in Toriño, Gausden, Etches, Rankin, Marshall & Gostling, 2023. 

DOI: 10.1080/02724634.2022.2125813 

  twitter.com/PabloTorino4

  Researchgate.net/publication/364672796

(artwork by S. Gausden).

 

Abstract

A large mawsoniid coelacanth from the lower part of the marine Kimmeridge Clay Formation of England (Kimmeridgian, Upper Jurassic) is studied here. The material is constituted by a group of bones from the head and shoulder girdle of a considerably large individual (estimated length ca. 1.5 m), including the left angular, left dentary, left prearticular, left palatoquadrate complex, both ceratohyals and right cleithrum. Characters such as the coarse external ornamentation of the angular, and the robustness of the quadrate and the cleithrum allow classification of the individual as a member of the Mawsoniidae; whereas the configuration of external bones of the lower jaw (ornamentation of the angular constituted mainly by longitudinal ridges, the presence of a lateral swelling in the dentary) indicates stronger Gondwanan affinities than previously expected (i.e., with the genus Mawsonia, up to now only recorded in South America by the end of the Jurassic). Considering the above, two alternative evolutionary, paleobiogeographic, and taxonomic scenarios are discussed: (1) the new individual can be referred to the European mawsoniid genus Trachymetopon (Lower–Middle Jurassic), in which case it should be assumed this genus reached the Upper Jurassic, and with a morphological variability higher than previously suspected (including some characters previously assumed as diagnostic for Mawsonia). Or (2) an unknown Mawsonia-like form was present in the Upper Jurassic of Europe. The last scenario puts the identification of isolated elements of European Jurassic giant mawsoniids in a new complex taxonomic and paleobiogeographic context, which will deserve further research.

  

 

A, stratigraphic profile of the lower part of the Kimmeridge Clay Formation indicating the level where the material was collected (adapted from Gallois, 2020); B, photograph of the collecting site at Ringstead Bay (one of the authors –S. Etches– for scale).

  Mawsoniidae gen. et sp. indet. (MJML K785).
A, schematic anatomical restoration of the head in left lateral view, showing the preserved bones (missing gray parts based on Maisey 1986; Toriño et al., 2021a); B, hypothetical life restoration

(artwork by S. Gausden).

 A, map showing the geographic provenance of the material studied in this work; B, paleogeographic context during Kimmeridge Clay times, with special reference to Laurasian masses (based on the reconstructions of Cox, 2020 after Callomon, 1985; Thierry, 2000; Gallois, 2020; Stumpf et al., 2021)

  

 

 

Pablo Toriño, Shane F. Gausden, Steve Etches, Kathryn Rankin, John E. A. Marshall and Neil J. Gostling. 2023. An enigmatic large mawsoniid coelacanth (Sarcopterygii, Actinistia) from the Upper Jurassic Kimmeridge Clay Formation of England. Journal of Vertebrate Paleontology. 42(1);  e2125813. DOI: 10.1080/02724634.2022.2125813 

  twitter.com/PabloTorino4/status/1585261494916235265

 Researchgate.net/publication/364672796_An_enigmatic_large_mawsoniid_coelacanth_from_the_Upper_Jurassic_Kimmeridge_Clay_Formation_of_England

[Paleontology • 2023] Vectidromeus insularis • A New hypsilophodontid Dinosaur (Ornithopoda: Hypsilophodontidae) from the Lower Cretaceous Wessex Formation of the Isle of Wight, England

 Vectidromeus insularis

 Longrich, Martill, Munt, Green, Penn & Smith, 2023.

DOI: 10.1016/j.cretres.2023.105707  

NickLongrich.com  twitter.com/NickLongrich

artwork by Emily Willoughby

 

Abstract

The Lower Cretaceous Wessex Formation of the Isle of Wight, UK, has produced a diverse dinosaurian fauna over the past 150 years. Hypsilophodontids are the most common small dinosaurs in the assemblage. Currently all hypsilophodontids are referred to Hypsilophodon foxii, originally described based on skulls and skeletons from the Hypsilophodon bed near Cowleaze Chine, in the uppermost Wessex Formation. We report a new hypsilophodontid, Vectidromeus insularis gen. et sp. nov., from exposures near Sudmoor Point, lying at the base of the exposed Wessex, ∼150 m below the Hypsilophodon beds. Associated elements of the dorsal vertebrae, pelvis, hindlimbs, and tail are preserved. The specimen represents a juvenile, but differs from adult and juvenile Hypsilophodon foxii in the short and deep posterior iliac blade, short pubic peduncle, laterally exposed brevis fossa, rectangular ischia, and large fourth trochanter. Vectidromeus adds to the diversity of dinosaurs in the Wessex Formation. With other putative hypsilophodontids now assigned to other families, the Hypsilophodontidae currently comprises just Hypsilophodon and Vectidromeus, both from the Wessex Formation of the Isle of Wight. Hypsilophodontidae appear to be endemic to the Early Cretaceous of Europe.

Systematic Palaeontology

Dinosauria Owen 1842

Ornithischia Seeley 1887

Ornithopoda Marsh 1881

Hypsilophodontidae Dollo 1882

Vectidromeus insularis gen. et sp. nov.

Etymology. Genus name = Vectis, the Roman name for the Isle of Wight + Greek dromaeus, = runner; species name from the Latin insularis = insular.

 

Nicholas R. Longrich, David M. Martill, Martin Munt, Mick Green, Mark Penn and Shaun Smith. 2023. Vectidromeus insularis, A New hypsilophodontid Dinosaur from the Lower Cretaceous Wessex Formation of the Isle of Wight, England. Cretaceous Research. In Press, 105707.  DOI: 10.1016/j.cretres.2023.105707

 twitter.com/NickLongrich/status/1702207787181527527

A new hypsilophodont dinosaur from the Isle of Wight, England

 NickLongrich.com/blog/a-new-hypsilophodont-dinosaur-from-the-isle-of-wight-england

 twitter.com/UniofBathNews/status/1702231345945084099

[Paleontology • 2023] Vectipelta barretti • A New ankylosaurian Dinosaur (Ankylosauria: Nodosauridae) from the Lower Cretaceous Wessex Formation of the Isle of Wight, UK

Vectipelta barretti 

Pond, Strachan, Raven, Simpson, Morgan & Maidment, 2023

DOI: 10.1080/14772019.2023.2210577  

Abstract

The Wealden Group of southern England was deposited by rivers, on floodplains and in lagoons during the Early Cretaceous. Two historically significant ankylosaurs, Polacanthus and Hylaeosaurus, are currently known from its deposits; Hylaeosaurus from the ‘lower Wealden fauna’ and Polacanthus from the ‘upper Wealden fauna’. Here, we describe a new genus and species of ankylosaur from the Wessex Formation of the Isle of Wight, which is characterized by numerous postcranial autapomorphies. Vectipelta barretti gen. et sp. nov. is 6–8 million years older than Polacanthus, and at least 3 million years younger than Hylaeosaurus, suggesting a more complicated pattern of faunal turnover in the Wealden Group than previously realized. Vectipelta does not appear to be closely related to either of the other Wealden taxa, but instead is found in a clade with two Chinese ankylosaurs, suggesting a complex pattern of dispersal to and from Europe, North America and Asia during the Early Cretaceous. The historic practise of cataloguing all ankylosaur material from the Wessex Formation as ‘Polacanthus’ has potentially prevented a diversity of taxa from being discovered, and new and existing material in museum collections should be re-appraised using an autapomorphy-driven approach.

 

Keywords: Dinosauria, Ornithischia, Wealden Group, Barremian, osteology, taxonomy

 

Stuart Pond, Sarah-Jane Strachan, Thomas J. Raven, Martin I. Simpson, Kirsty Morgan and Susannah C. R. Maidment. 2023. Vectipelta barretti, A New ankylosaurian Dinosaur from the Lower Cretaceous Wessex Formation of the Isle of Wight, UK. Journal of Systematic Palaeontology. 21(1); 2210577. DOI: 10.1080/14772019.2023.2210577  

 nhm.ac.uk/discover/news/2023/june/new-species-of-dinosaur-named-after-museum-scientist-paul-barrett.html

[Paleontology • 2023] Bentonyx sidensis • Unique Dentition of rhynchosaurs (Archosauromorpha: Rhynchosauria) and their Two-phase Success as Herbivores in the Triassic

Bentonyx sidensis  Langer, Montefeltro, Hone, Whatley & Schultz, 2010

in Sethapanichsakul, Coram & Benton, 2023. 

DOI: 10.1111/pala.12654

Abstract

Rhynchosaurs were key herbivores over much of the world in the Middle and Late Triassic, often dominating their faunas ecologically, and much of their success may relate to their dentition. They show the unique ankylothecodont mode of tooth implantation, with deep roots embedded in the bone of the jaw and low crowns that were rapidly worn down in use. During growth, the main area of oral food processing, located in the middle and posterior portions of the occlusal surfaces of the jaws, moved posteriorly relative to the anterior tips of the jaws, which curved up. As the maxilla and dentary grew by addition of new bone posteriorly, the dental lamina fed in new teeth at the back of the tooth rows. CT scanning of the holotype skull of Bentonyx sidensis from the Middle Triassic of England reveals previously concealed details of the dentition. Together with new dentary material from the same location, this has enabled us to examine the tooth replacement process and elucidate ontogenetic changes in dentition and jaw morphology as the animals aged. There were major changes in rhynchosaur anatomy and function through their evolutionary history, with the early forms of the Middle Triassic dying out before or during the Carnian Pluvial Episode (233–232 Ma), and the subclade Hyperodapedontinae, with broad skulls and adaptations to chop tough vegetation, subsequently diversifying worldwide in a successful ecological expansion until their global extinction 227–225 Ma.

Keywords: dentition, rhynchosaur, tooth replacement, herbivory, Triassic, Carnian Pluvial Episode

Bentonyx sidensis 

 

Thitiwoot Sethapanichsakul, Robert A. Coram and Michael J. Benton. 2023. Unique Dentition of rhynchosaurs and their Two-phase Success as Herbivores in the Triassic. Palaeontology. 66(3); e12654. DOI: 10.1111/pala.12654