Albanerpetontidae, Fox & Naylor, 1982
|
publication ID |
https://doi.org/ 10.5252/geodiversitas2022v44a25 |
|
publication LSID |
urn:lsid:zoobank.org:pub:EA12DCB7-A5BE-4763-B805-25087EBD726D |
|
DOI |
https://doi.org/10.5281/zenodo.6929025 |
|
persistent identifier |
https://treatment.plazi.org/id/03C887B9-FFB8-FFE5-7405-A06EFABAFABC |
|
treatment provided by |
Felipe |
|
scientific name |
Albanerpetontidae |
| status |
|
Albanerpetontidae indet.
( Fig. 9 View FIG )
DESCRIPTION
Albanerpetontids are represented in Angeac-Charente by numerous and diverse bones, including dentaries, premaxillae, maxillae, vertebrae and forelimb bones ( Fig. 9 View FIG 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 View FIG ); 2) pleurodont, chisel-like and regularly arranged non-pedicellate teeth, labiolingually compressed and bearing three faint, mesiodistally aligned cuspules ( Fig. 9 View FIG 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 View FIG ; 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 View FIG ; 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 View FIG I-K) are amphicoelous, hourglass-shaped and bear a short unicipital transverse process. The centrum is narrowly constricted at its center ( Fig. 9I, K View FIG ) and the cotyles are circular in outline and have thickened rims ( Fig. 9J View FIG ). As in other albanerpetontid trunk vertebrae described elsewhere, the notochordal canal is anteroposteriorly continuous ( Fig. 9J View FIG ; 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 View FIG ) and maxilla ( Fig.9C View FIG ) have a deep pars dentalis and the dentary ( Fig. 9A, B, F, G View FIG ) 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 View FIG ; Gardner 2000). The maxilla has a low, posteriorly tapered pars facialis ( Fig. 9C View FIG ; Gardner 1999a, 2000). On the dentary, the Meckelian canal is closed anteriorly, and the subdental shelf is low, narrow and gutterlike anteriorly ( Fig. 9A View FIG ; 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 View FIG ; 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 View FIG ), 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.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.