Osteology and affinities of Dollo's goniopholidid (Mesoeucrocodylia) from the Early Cretaceous of Bernissart, Belgium

Abstract

The two specimens originally referred by Louis Dollo to Goniopholis simus from the Early Cretaceous of Bernissart, Belgium are described. They consist of fully articulated skeletons, one missing the skull and mandibles. Comparison of these specimens with recently revised specimens from the Wealden of England allows confirmation that the Belgian specimens are referable to the goniopholidid Anteophthalmosuchus hooleyi. The Belgian specimens are the most completely known representatives of this species but also of any Goniopholididae. The study of the postcranial skeletons from Bernissart reveals that the appendicular skeleton closely resembles that of derived neosuchians. The dorsal and ventral shields present a morphology directly comparable to other goniopholidids and pholidosaurids. Such observations stress on the necessity to gather an osteological database of postcranial elements to test relationships of the various neosuchian lineages. Goniopholididae were relatively diverse during the Early Cretaceous of Europe and depending on taxonomic opinion, three to five genera are recognized: Anteophthalmosuchus, Goniopholis, Hulkepholis and possibly Vectisuchus and Nannosuchus.

Spatiotemporal sampling patterns in the 230 million year fossil record of terrestrial crocodylomorphs and their impact on diversity

“…; Martin et al . ). Although postcrania are usually listed in taxon descriptions, they are not always figured or described in detail, and this bias subsequently affects the choice of characters that end up being incorporated into phylogenetic data sets.…”

A new goniopholidid crocodyliform,Hulkepholis rorisp. nov. from the Camarillas Formation (early Barremian) in Galve, Spain)

“…One of the features shared by both genera is the development of an anteromedial border at the glenoid area that forms a stout knob for the insertion of the muscle pterygoideus dorsalis. This feature has not been described in Anteophthalmosuchus escuchae from CCB-1 (Coco Corta Barrabasa site in Andorra, Teruel; Puértolas-Pascual, Canudo & Sender, 2015), but it is visible in the mandible of the specimen IRSNB R-47, described as the anteriomedial edge of the projected glenoid in Martin, Delfino & Smith (2016, fig. 7).The similar shape of the iliac blade (Fig.…”

“…Both prefrontal pillars are turned and medially directed forming an angle less than 90°, as occurs in H. plotos , Anteophthalmosuchus escuchae and AR-1-3422 and as described in Dollo’s Anteophthalmosuchus specimen IRSNB R47 (Martin, Delfino & Smith, 2016). The connection with the palatine process of the pillars is solid.…”

“…The exoccipitals form part of the dorsal margin of the foramen magnum; they develop a wing-like projection over the foramen magnum excluding the supraoccipital. The occipital condyle is framed by parasagittal robust exoccipital pedicels as occurs in Goniopholis , and as described in the specimen IRSNB R47 by Martin, Delfino & Smith (2016), H. willetti and the goniopholidids from Ariño. The cranial hypoglossal nerve (pair XII) and the posterior carotid foramen open on the exoccipitals; the posterior carotid foramen laterodorsal to the lateral basioccipital tubera, and cranial nerve XII lateral to the exoccipital pedicels of the occipital condyle (Fig 9).…”

“…However, the family also possesses a set of primitive features (e.g., palatines participating in the choana, amphicoelous vertebrae, two rows of paravertebral osteoderms) together with several characteristic traits, such as an extremely flattened rostrum, maxillary depressions, two parasagittal palatal fossae, and an open cranioquadrate passage (Steel, 1973; Buffetaut, 1982; De Andrade et al, 2011; Adams, 2013). Despite their abundant and diverse fossil record, the phenotypic variability and functionality of goniopholidid features are not yet fully understood, which is corroborated by the incongruence between taxonomy and phylogeny (De Andrade et al, 2011; Allen, 2012; Pritchard et al, 2013; Adams, 2013; Puértolas-Pascual, Canudo & Sender, 2015; Martin, Delfino & Smith, 2016; Ristevski et al, 2018). Recent studies providing better and more comprehensive anatomical descriptions are correcting former misconceptions, and providing evidence of their extraordinary adaptations and diversity during the Mesozoic (De Andrade & Hornung, 2011; De Andrade et al, 2011; Salisbury & Naish, 2011; Pritchard et al, 2013; Ristevski et al, 2018).…”