Morphological variability and shell characterization of the European uppermost Jurassic to lowermost Cretaceous stem turtle Pleurosternon bullockii (Paracryptodira, Pleurosternidae)

Cranial osteology, taxonomic reassessment, and phylogenetic relationships of the Early Cretaceous (Aptian-Albian) turtle Trinitichelys hiatti (Paracryptodira)

“…The character scoring for Arundelemys dardeni and Trinitichelys hiatti were updated following the latest insights into the cranial anatomy of these taxa ( Evers, Rollot & Joyce, 2021 ; this study; see Supplemental Information ). The scoring for Pleurosternon bullockii were updated following recent investigation of morphological variability in the shell of this taxon ( Guerrero & Pérez-García, 2020 , 2021 ; see Supplemental Information ) and additional changes were implemented for Compsemys victa , Peckemys brinkman , Helochelydra nopcsai , Naomichelys speciosa , and Kallokibotion bajazidi (see Supplemental Information ).…”

An alternative interpretation of small-bodied turtles from the “Middle Purbeck” of England as a new species of compsemydid turtle

“…Our primary comparative sources are as follows: Compsemys (a.k.a. Berruchelus) russelli (Pérez-García, 2012) from the Paleocene of France, as described by Pérez-García (2012); Calissounemys matheroni Tong et al, 2022 from the Campanian of France, as described by Tong et al (2022); Compsemys victa Leidy, 1856 from the Paleocene of New Mexico, as described by Gilmore (1919); Peltochelys duchastelii Dollo, 1884 from the Early Cretaceous (middle Barremian to early Aptian) of Belgium, as described by Joyce and Rollot (2020); Pleurosternon bullockii from the Early Cretaceous (Berriasian) of England, as described by Guerrero and Pérez-García (2021a); and Selenemys lusitanica Pérez-García & Ortega, 2011 from the Late Jurassic (Kimmeridgian) of Portugal, as described by Pérez-García and Ortega (2011).…”

“…Late Jurassic (Tithonian) to Early Cretaceous (Berriasian) sediments of the Purbeck Group, which are broadly exposed along the southern coast of England, have yielded a particularly rich collection of fossil turtles over the course of the last two centuries (Owen 1842(Owen , 1853Mantell 1844;Seeley 1869;Lydekker 1889a, b;Woodward 1909;Watson 1910a, b;Kemp 1975, 1976;Barrett et al 2002). At present, at least five species are recognized as valid from these strata: the abundant pleurosternid Pleurosternon bullockii Owen, 1842, which is known from a single cranium and rich shell remains (Milner 2004;Evers et al 2020;Guerrero and Pérez-García 2021a), the indeterminate paracryptodire Dorsetochelys typocardium (Seeley, 1869) (Milner 2004;Pérez-García 2014), two helochelydrids, including "Helochelydra" anglica (Lydekker, 1889b) and an undefined form (Barrett et al 2002;Joyce 2017) and the shell taxon Hylaeochelys belli (Mantell, 1844), which is a plausible thalassochelydian turtle, synonymous with the skull taxon Dorsetochelys delairi Evans & Kemp, 1976 (Anquetin and André 2020). Lydekker (1889a) was the first to figure and describe the well-preserved, but crushed shell of a small-bodied turtle from the Middle Purbeck.…”

Mandibular anatomy of the paracryptodire Glyptops ornatus supports active hunting behavior in a Jurassic turtle

“…Paracryptodiran phylogeny likely suffers from taphonomic artifacts that are common in turtles: some fossil species are only known from skulls (e.g., Arundelemys dardeni : Evers et al, 2021; Lipka et al, 2006, Uluops uluops : Carpenter & Bakker, 1990; Rollot et al, 2021a), whereas others do not preserve skull material and are primarily known from shells (e.g., Toremys cassiopeia : Pérez‐García et al, 2015; Selenemys lusitanica : Pérez‐García & Ortega, 2011). Only relatively few specimens are known from more complete material that includes the skull and shell, but these are often either not well preserved, incompletely described, or taxonomic referrals have been controversial (e.g., Compsemys victa : Gilmore, 1919; Lyson & Joyce, 2011, Dinochelys whitei : Gaffney, 1979b, Glyptops ornatus : Gaffney, 1979b, Pleurosternon bullockii : e.g., Evans & Kemp, 1975; Evers et al, 2020; Guerrero & Pérez‐García, 2021; Joyce et al, 2022; Milner, 2004). Recovering new anatomical details from these species may be important in stabilizing paracryptodiran phylogeny by documenting variation that has previously not been phylogenetically considered.…”