cf. Cteniogenys

(Fig. 16 A-E)

DESCRIPTION

A characteristic robust vertebra (Fig. 16 A-C), as well as a smaller vertebra that probably belongs to a juvenile individual (Fig. 16D, E), have been discovered among the microremains. Both centra are amphicoelous, with an opened neurocentral suture. Dorsally, a distinct longitudinal ridge is laterally bordered by longitudinal grooves on the floor of the neural canal (Fig. 16A). In ventral view, the lower half of the centrum is pinched into a keel (Fig. 16D). The margins of the cotyle are thick (Fig. 16E). All these characters are reminiscent of choristoderan reptiles (Evans 1991; Averianov et al. 2006; Vullo et al. 2014; Haddoumi et al. 2016; Lasseron et al. 2020). ANG M-20 is nearly identical to the vertebra of Cteniogenys figured by Evans & Milner (1994: fig.18.5). Hence, it is here tentatively assigned to this genus, although this identification needs to be substantiated with additional material. These freshwater or amphibious diapsids are well known in Laurasia (Matsumoto et al. 2013), but have also been reported from the Jurassic-Cretaceous transition of North Africa (Lasseron et al. 2020). In the Lower Cretaceous of Asia, the diversity and abundance of choristoderans is particularly high in the faunal assemblages, in which crocodyliforms are scarce (Matsumoto et al. 2015; Skutschas & Vitenko 2017). Conversely, the abundance and diversity of crocodyliforms at Angeac-Charente may explain the scaricity of choristoderans.