Albanerpetontidae Fox & Naylor 1982
Creators: name: Allain, Ronan
name: Vullo, Romain
name: Rozada, Lee
name: Anquetin, Jérémy
name: Bourgeais, Renaud
name: Goedert, Jean
name: Lasseron, Maxime
name: Martin, Jeremy E.
name: Pérez-García, Adán
name: Fabrègues, Claire Peyre De
name: Royo-Torres, Rafael
name: Augier, Dominique
name: Bailly, Gilles
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Amphibia
Gymnophiona
Albanerpetontidae

description: Albanerpetontidae indet.
(Fig. 9)
DESCRIPTION
Albanerpetontids are represented in Angeac-Charente by numerous and diverse bones, including dentaries, premaxillae, maxillae, vertebrae and forelimb bones (Fig. 9 A-K). All the material was recovered from screen washing residues. It is always disarticulated, and almost always fragmentary. Several diagnostic characters allow their assignment to the Albanerpetontidae, including: 1) intertonguing symphyseal joint between dentaries, in a mortise-and-tenon style (Fox & Naylor 1982; Milner 1988; McGowan & Evans 1995; McGowan 1996, 2002; Gardner 1999b, 2000; Gardner et al. 2003; Sweetman & Gardner 2013; Matsumoto & Evans 2018). In the Angeac-Charente specimens, there are two symphyseal prongs (Fig. 9A, B); 2) pleurodont, chisel-like and regularly arranged non-pedicellate teeth, labiolingually compressed and bearing three faint, mesiodistally aligned cuspules (Fig. 9 A-G; Fox & Naylor 1982; Gardner 1999a, b, 2000; McGowan & Evans 1995; Sweetman & Gardner 2013; Matsumoto & Evans 2018); and 3) foramina arranged in line on external face of dentary (Fig. 9F; Fox & Naylor 1982; Gardner 2000).
In Angeac-Charente albanerpetontids, the maxilla is unornamented labially, except for scattered external nutritive foramina that are characteristic of the group (Fig.9D; Fox & Naylor 1982; Gardner 2000). In this respect, they differ from Albanerpeton inexpectatum from the Miocene of France (Gardner 1999a). As in other albanerpetontid for which trunk vertebrae have been described (Estes & Hoffstetter 1976; McGowan 1996, 2002; McGowan & Ensom 1997; Sweetman & Gardner 2013; Matsumoto & Evans 2018), those from the Angeac-Charente material (Fig. 9 I-K) are amphicoelous, hourglass-shaped and bear a short unicipital transverse process. The centrum is narrowly constricted at its center (Fig. 9I, K) and the cotyles are circular in outline and have thickened rims (Fig. 9J). As in other albanerpetontid trunk vertebrae described elsewhere, the notochordal canal is anteroposteriorly continuous (Fig. 9J; Sweetman & Gardner 2013) and thus the vertebrae are fully notochordal.
Angeac-Charente specimens also show numerous features that have been described in other albanerpetontids and allow the distinction from other lissamphibians and lizards.The premaxilla (Fig.9D, E) and maxilla (Fig.9C) have a deep pars dentalis and the dentary (Fig. 9A, B, F, G) has a tall dental parapet, allowing the attachment of highly pleurodont teeth (Gardner 2000). Upper jaws are also characterized by a prominent, shelf-like pars palatinum lingually (Fig. 9E; Gardner 2000). The maxilla has a low, posteriorly tapered pars facialis (Fig. 9C; Gardner 1999a, 2000). On the dentary, the Meckelian canal is closed anteriorly, and the subdental shelf is low, narrow and gutterlike anteriorly (Fig. 9A; Gardner 1999a, b, 2000). As in other known albanerpetontid species, the humeral condyle is spherical, fully ossified and larger than the adjacent radial epicondyle (Fig. 9H; Sweetman & Gardner 2013). Above this humeral ball is a triangular and well-defined cubital fossa, at the proximal extremity of which a small foramen can be seen (Fig. 9H), as also reported for Albanerpeton inexpectatum (Estes & Hoffstetter 1976) and Wesserpeton evansae (Sweetman & Gardner 2013).
The albanerpetontids from Angeac-Charente differ from Anoualerpeton and Albanerpeton nexuosum, but resemble other Albanerpeton species, Celtedens and Wesserpeton in having dentaries and maxillae with relatively straight occlusal margins, and teeth weakly heterodont in size (Sweetman & Gardner 2013). Unfortunately, the diagnostic characters necessary for identification at the generic level are lacking. Neither the maxilla nor the dentary is diagnostic for Albanerpeton and Celtedens (Gardner 2000), as their diagnoses are based on frontal characters (Gardner 1999a, b, 2000; McGowan & Evans 1995; McGowan 2002). We did not find any frontal bones in the Angeac-Charente material, and so we cannot attribute the albanerpetontid material to these genera with certainty. Within Albanerpeton, the premaxilla is the most taxonomically informative bone for species (Gardner 1999b, 2000), but the specimens found to date at Angeac-Charente are too incomplete to be relevant.
Thus, considering the characters mentioned above, we can attribute the Angeac-Charente specimens to the family Albanerpetontidae, but so far the material is too incomplete to allow a further attribution at the generic and specific level.
description: Published as part of Allain, Ronan, Vullo, Romain, Rozada, Lee, Anquetin, Jérémy, Bourgeais, Renaud, Goedert, Jean, Lasseron, Maxime, Martin, Jeremy E., Pérez-García, Adán, Fabrègues, Claire Peyre De, Royo-Torres, Rafael, Augier, Dominique & Bailly, Gilles, 2022, Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J / K boundary, pp. 683-752 in Geodiversitas 44 (25) on page 695, DOI: 10.5252/geodiversitas2022v44a25, http://zenodo.org/record/6902033