More-complete remains ofProcolpochelys charlestonensis(Oligocene, South Carolina), an occurrence ofEuclastes(upper Eocene, South Carolina), and their bearing on Cenozoic pancheloniid sea turtle distribution and phylogeny

Abstract

Abstract.-New and more-complete material of Procolpochelys charlestonensis Weems and Sanders, 2014 provides the first detailed information on the skull, jaw, and plastron of this species, which occurs in the Oligocene Ashley and Chandler Bridge formations near Charleston, South Carolina. This material allows a much more detailed comparison of this turtle with the co-occurring pancheloniid species Ashleychelys palmeri Weems and Sanders, 2014 and Carolinochelys wilsoni Hay, 1923a, as well as with its Miocene successor Procolpochelys grandaeva (Leidy, 1851). Fused dentaries, found in the Cooper River north of Charleston, belong to the pancheloniid genus Euclastes, previously known only from the Upper Cretaceous and Paleocene. This specimen, apparently from the upper Eocene Parkers Ferry Formation, expands the temporal range of this genus and indicates that Euclastes survived in the North Atlantic basin far longer than was previously known. These new finds, combined with previous records of fossil pancheloniid sea turtles, provide an improved picture of the temporal distribution, evolutionary trends, and likely phylogeny of pancheloniids from the Late Cretaceous to the present.

Comparative analysis of the shape and size of the middle ear cavity of turtles reveals no correlation with habitat ecology

“…We used an updated version of the informal supertree of Foth & Joyce (2016) as the phylogenetic backbone for various statistical analyses, which differs from the published version in the position of some extinct marine turtles. In particular, pan-chelonioids were resolved according to Weems & Brown (2017) and protostegid turtles, including the 'dermochelyoids' of Bardet et al (2013) and Lapparent de Broin et al (2014), were placed as sister to thalassochelydians, as originally proposed by Joyce (2007) (but see Raselli, 2018 and for alternative phylogenetic placements for protostegids). The tree was time-calibrated in R using the package paleotree (Bapst, 2012) using information from the ages of fossils and from molecular clock studies.…”

The turtles from the upper Eocene, Osona County (Ebro Basin, Catalonia, Spain): new material and its faunistic and environmental context

“…The diagram of relationships proposed by Zangerl (1953bZangerl ( , 1971Zangerl ( , 1980 was supported by the introduction of all these taxa, and of others not studied by Zangerl (1953b) and Zangerl and Turn-bull (1955), in the cladistic analysis proposed by Parham and Pyenson (2010). New works included the late Eocene Priabonian Osonachelus decorata, coded by Lapparent de Broin et al (2014b), and several North American Senonian forms coded or examined by Weems and Brown (2017) and Weems and Sanders (2014). However, Lapparent de Broin et al (2014b) reported many problems relative to the phylogenetic position of some forms.…”

“…Some cladistic analyses performed for Chelonioidea and Dermochelyoidea provided relevant data for the definitions and separation of subgroups (Bardet et al, 2013;Brinkman et al, 2009;Hirayama, 1995Hirayama, , 1998Hirayama and Chitoku, 1996;Joyce et al, 2004; Pérez-García and Lapparent de Broin, 2013; Lapparent de Broin et al, 2014a, b;Parham and Fastovsky, 1997;Parham and Pyenson, 2010). Only eight shell characters were coded for Eochelone brabantica in the cladistic analysis characters proposed by Parham and Pyenson (2010) (subsequently used, with few modifications, by Lapparent de Broin et al, 2014b;Weems and Brown, 2017;Weems and Sanders, 2014). Other characters coded for this taxon corresponded to elements unknown in E. voltregana n. sp.…”

“…In this sense, the coding of several characteristics, which, united, constitute a single complex structure (such as the secondary palate) but are independently the ones from the others homoplastic in turtles of various unrelated families (Pleurodira as well as Cryptodira), may result in both the erroneous grouping of possibly not closely related taxa, and in the distribution of related forms in different clades which can be evidently recognized as related taxa at first view by some shared diagnostic features. This is shown in the cladograms provided by Lapparent de Broin et al (2014b) and Weems and Brown (2017), where all the Euclastes group members, possessing, objectively, the same palate and the same shell morphotypes, were not united (see remarks in online supplementary data of Lapparent de Broin et al, 2014b).…”

“…The skull (lacking here) could be relevant for the determination of this genus, but the shell and other postcranial remains also provide important information, which is exclusive for this form. The skull characteristics have traditionally mainly been employed in previous papers (Lapparent de Broin et al, 2014b;Parham and Pyenson, 2010;Weems and Brown, 2017). However, the Osona postcranial elements of the new taxon share an exclusive characteristic combination with Eochelone brabantica, allowing the attribution of the new material to a new species of this genus.…”