A new bernissartiid crocodyliform from the Lower Cretaceous Wessex Formation (Wealden Group, Barremian) of the Isle of Wight, southern England

Abstract

A substantially complete skull of a small crocodyliform recently found on the foreshore near Yaverland on the south-east coast of the Isle of Wight

Evolutionary relationships and systematics of Atoposauridae (Crocodylomorpha: Neosuchia): implications for the rise of Eusuchia

“…In addition to these goniopholids, we also included Pholidosaurus purbeckensis (Salisbury, ) as a further representative of ‘coelognathosuchian’ crocodyliforms ( sensu Martin et al ., ). We included Koumpiodontosuchus aprosdokiti to represent Bernissartiidae (Sweetman, Pedreira‐Segade & Vidovic, ). We also included the advanced neosuchians Wannchampsus kirpachi (Adams, ) and Shamosuchus djadochtaensis , based on Pol et al .…”

“…In the holotype specimen of Alligatorellus beaumonti , the posterior‐most maxillary teeth have a more labiolingually compressed, apically pointed morphology than the remaining teeth, similar to the ‘lanceolate’ morphology exhibited by several species of Theriosuchus (Schwarz & Salisbury, ; Lauprasert et al ., ) and Brillanceausuchus , as well as the bernissartiid Koumpiodontosuchus (Sweetman et al ., ). This is different to the homodont dentition typically reported for Alligatorellus , which is usually described as possessing simple pseudocaniniform teeth that are smooth and lack ridges or carinae (e.g.…”

“…Nonetheless, Tennant & Mannion () identified this heterogeneity in sculpting pattern as distinct from other atoposaurids and Theriosuchus , and considered it to be autapomorphic of Alligatorellus beaumonti . (S2) Surface of rostrum notably less sculpted than cranial table (C4.1) : See S2 for Alligatorellus for discussion of this character state. (S3) Relatively large lateral temporal fenestra, approximately 30% of the size of the orbit (C20.1) : A lateral temporal fenestra of this size with respect to the orbit represents the intermediate condition in our analyses. This relatively large size is unique amongst atoposaurids, but is also shared with T. pusillus , Koumpiodontosuchus (Sweetman et al ., ), and protosuchians, as well as the advanced neosuchians Shamosuchus (Pol et al ., ), Isisfordia (Salisbury et al ., ), and Brillanceausuchus . In other taxa, such as Allodaposuchus precedens , the lateral temporal fenestra approaches the size of the orbit (Buscalioni et al ., ). (S4) Smooth contact between maxilla and jugal (C51.2) : As noted above, the pattern of sculpting on the anterior portion of the dorsal surface of the skull is diagnostic for the different species of Alligatorellus .…”

“…This ‘low‐crowned’ morphology is distinct from the ‘low‐crowned’ tribodont dentition of Bernissartia and Koumpiodontosuchus (Buffetaut & Ford, 1979; Schwarz‐Wings et al ., ; Sweetman et al ., ), in which the teeth are multicusped. However, both morphologies probably had a similar function in crushing harder prey items (e.g.…”

Transformation of Quotient Values for their use as Continuous Cladistic Characters

“…(e.g. Lü et al 2009; Wang et al 2009; Andres et al 2014; Vidovic and Martill 2014) in Pterosauria, and the position and composition of Tethysuchia and/or Thalattosuchia in crocodilomorph phylogeny (Jouve 2009; Sweetman et al 2015). Some researchers opt to test new taxa or theories against multiple phylogenies (e.g.…”