Goniopholis sp.

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, Geodiversitas 44 (25), pp. 683-752 : 704-706

Goniopholis sp.

( Fig. 18 )

DESCRIPTION

In addition to fragmentary cranial remains and numerous isolated teeth, a nearly complete skull and mandibular elements (ANG1 8-5914, 5920, 5921 and 5925) of a single individual have been excavated and prepared in 2018 ( Fig. 18 ). The skull is broken transversally in front of the orbits and the rostrum is split longitudinally along the nasals and premaxillae. The associated mandible preserves both dentaries. In comparison with other goniopholidids from Europe, this skull is notable for its exquisite preservation, being minimally compacted dorsoventrally.

Based on recent works ( Salisbury et al. 1999; Schwarz 2002; Andrade et al. 2011; Buscalioni et al. 2013; Puértolas-Pascual et al. 2015; Martin et al. 2016a), several diagnostic characters used in combination permit assignment of this specimen to Goniopholididae , including: 1) a mesorostrine condition with a rostrum to skull ratio c. 0.65; 2) constricted outline of the upper jaw at the level of the premaxillary-maxillary suture; 3) double-caniniform maxillary teeth 4+5; 4) confluent dentary alveoli 3+4; 5) orbits smaller than supratemporal fenestrae and slightly smaller than frontal width at interorbital level; 6) skull table and dorsal surface of quadratojugal and jugal densely covered by large circular cupules; 7) internal choanae anteriorly bound by palatines; 8) semi-arched and widely expanded premaxillae with fifth alveolus more laterally placed than the rest of the premaxillary tooth row; and 9) absence of contact between ectopterygoid and posterior margin of maxillary tooth row.

The Angeac-Charente specimen (ANG18-5914, 5920, 5921 and 5925) also exhibits several characters that permit provisional assignment to the genus Goniopholis . Among these, antorbital and interorbital ornamentation is informative. The presence of periorbital crests on the prefrontal and lacrimal are present in Goniopholis ( Andrade & Hornung 2011) but absent in Anteophthalmosuchus and Hulkepholis ( Salisbury & Naish 2011; Buscalioni et al. 2013; Martin et al. 2016a). The interorbital ridge is restricted to the frontal in Hulkepholis ( Salisbury & Naish 2011; Buscalioni et al. 2013). In the Angeac-Charente specimen, the presence of both antorbital and interorbital crests is also a character shared with Goniopholis . A short postorbital spine is present in the Angeac-Charente specimen, a condition similar to other specimens of the genus Goniopholis ( Salisbury et al. 1999; Schwarz 2002; Andrade et al. 2011) but unlike Anteophthalmosuchus in which this spine is longer, almost contacting the anterior margin of the orbits ( Salisbury & Naish 2011; Martin et al. 2016a). The Angeac-Charente specimen is also similar in its maxillary tooth count (20) to Goniopholis kiplingi ( Andrade et al. 2011) and with Anteophthalmosuchus , which possesses 19 alveoli ( Martin et al. 2016a). The maxillary alveolar count has not been established for Goniopholis simus ( Salisbury et al. 1999) . However, this count is less than that of the goniopholidid Hulkepholis willetti , in which at least 24 maxillary alveoli are present ( Salisbury & Naish 2011). Obvious differences in rostrum proportions are observed with Vectisuchus and Hulkepholis , which possess long and narrow rostra ( Buffetaut & Hutt 1980; Salisbury & Naish 2011; Buscalioni et al. 2013). As in Anteophthalmosuchus and Goniopholis , the palpebral in the specimen from Angeac-Charente is small and not large and triangular as in Hulkepholis ( Salisbury & Naish 2011; Buscalioni et al. 2013; Martin et al. 2016a). Comparison with Nannosuchus will not be discussed here as this taxon has been viewed either as a juvenile of Goniopholis ( Salisbury 2002) or as a valid taxon ( Andrade et al. 2011). Therefore, considering the characters mentioned above, we tentatively refer the Angeac-Charente specimens to Goniopholis sp.

A detailed description of the Angeac-Charente material will be provided elsewhere. In the meantime, a study of the numerous goniopholid specimens from Cherves-de-Cognac and assigned to Goniopholis (Raslan-Loubatié 2007) will provide a useful basis for discussing morphological variability within a goniopholidid population. Preliminary observations concerning the Angeac-Charente specimen do not reveal any obvious morphological differences between the goniopholidids at both localities but further study is required.

Figures

FIG. 18. — Goniopholidid crocodyliform Angeac-Charente: A, D, left dentary of Goniopholis sp. (ANG18-5925) in dorsal (A) and ventral (D) views; B, C, skull of Goniopholis sp. (ANG18-5914, ANG18-5920, ANG18-5921) in dorsal (B) and ventral (C) views. Scale bar: 10 cm.