Goniopholis, OWEN, 1841

Andrade, Marco Brandalise De, Edmonds, Richard, Benton, Michael J. & Schouten, Remmert, 2011, A new Berriasian species of Goniopholis (Mesoeucrocodylia, Neosuchia) from England, and a review of the genus, Zoological Journal of the Linnean Society 163 (5), pp. 644-645 : 644-645

GENUS GONIOPHOLIS OWEN, 1841

Type-species: Goniopholis crassidens Owen, 1841 1841 Goniopholis crassidens Owen

1878 Goniopholis simus Owen

1999 Goniopholis crassidens (Owen) Salisbury et al. 1999 Goniopholis simus (Owen) Salisbury et al.

2002 Goniopholis simus (Owen) Salisbury et al.

2002 Goniopholis baryglyphaeus Schwarz.

Etymology: After Gonius , meaning ‘angled’; and Pholis , meaning ‘scale’.

Geographical range: Continental Europe and England.

Stratigraphical range: Upper Jurassic (Kimmeridgian) to Lower Cretaceous (Berriasian).

Diagnosis for the genus: Neosuchian crocodylomorphs with the following combination of characteristics: platyrostral mesorostrine- sublongirostrine skull, laterally expanded premaxillae, shaped like an axe blade in dorsal view; naris dorsally orientated; perinarial crests present, robust and larger lateral to the naris; naso-oral fossa longer than wider, diamond-shaped; maxilla festooned, with well-defined anterior wave, projecting laterally and ventrally; deep maxillary depressions facing laterally, located next to the jugal suture, with abrupt margins around its entire perimeter and complex internal structure (i.e. divided internally by dorsoventrally orientated ridges); periorbital crests present and robust in structure; dorsal periorbital crest extending on lachrymal- prefrontal surfaces, next to the anterodorsal- dorsal border of the orbit, and presenting a notch at the prefrontal- lachrymal suture; ventral orbital crest formed by projecting jugal margin, which is deflected anterior to the orbit and delimits the ventral edge of a lachrymal fossa; anterior border of the orbit composed by lachrymal and jugal; extensive scar for the attachment of palpebral, reaching at least the lachrymal and prefrontal; frontal and postorbital in contact with palpebral; single palpebral with an overall triangular shape, firmly attached to the primary orbital border, and creating a secondary orbital border; frontal anterior process in a lower level relative to its main body; frontal anterior process separated from main body by a strong transfrontal crest, transversally orientated and bearing a medial buttress; frontal and prefrontal participating in the primary orbital border, but excluded from secondary orbital border (shared with Protosuchidae , Peirosauridae , and other Goniopoholididae) by the palpebral; postorbital with anterolateral process present, robust and short; supratemporal fossae medium to large, and square-shaped to subrectangular in shape; anterior face of palatine process at palate is truncated, with suture transversely orientated.

Remarks on diagnosis: Goniopholis is further characterized by the following features, frequently found in other Goniopholididae , as well as other crocodylomorphs: skull ornamentation dominated by subcircular pits, when present, with grooves absent or only poorly represented at maturity, not reaching the area next to the maxillary alveolar margin; internarial bar absent; premaxillary margin high anterior to naris; nasals contact premaxilla, excluded from naris; nasals contact lachrymals at medial margin only; postnarial fossa present; antorbital fenestra/fossa absent; lachrymal fossa greatly reduced, delimited dorsally and ventrally by crests; laterodorsally orientated orbits; prefrontals composing the anterior to medial borders of the orbits; frontal wide, flat, T-shaped; frontal-parietal contact broadly inside the intertemporal bar and supratemporal fossae, with parietal- postorbital contact not exposed at skull table; supratemporal fenestrae lacking an evident main axis; laterotemporal fenestrae longer than higher, laterodorsally orientated; jugal anterior ramus wide; postorbital bar inclined posteromedially; lateral surface of jugal- quadratojugal fully ornamented; cranioquadrate canal open laterally; otoccipital not enclosing the cranioquadrate passage; post-temporal foramen present, wider than higher; foramen squamosootoccipitalis present; choanal border composed by palatines and pterygoids; choanae lanceolate, ample, longer than wider, as narrow as the nasopharyngeal duct; ventral face of the nasopharyngeal duct not trenched; posterolateral palatine processes absent; palatine- ectopterygoid contact absent; pterygoids reach suborbital fenestra; dorsal surface of retroarticular process faces posterodorsally, with medial wing high and facing medially; five premaxillary, 18–20 maxillary, and 20–24 dentary alveoli; teeth crowns anisometric, subisomorphic (single cusped, caniniform), keeled, nonziphodont or false-ziphodont; poorly compressed (subcircular cross-section), well ornamented with basi-apical, poorly anastomosed, welldefined enamel ridges; maxillary teeth with oblique (paradistal) implantation; dorsal and ventral osteoderms present, forming an extensive dermal armour; dorsal armour composed of paired dermal scutes, set in two paramedial rows; paramedial osteoderms are subrectangular, wider than longer, not keeled, with a flat but strongly ornamented dorsal surface.

Taxonomic amendments

Considering this new definition, currently only three species may be considered as members of the genus Goniopholis : G. baryglyphaeus , G. kiplingi , and G. simus . All other references to the genus are in error. The impact on the taxonomy of Goniopholididae is not profound though, as most taxa have already been attributed or reverted to other genera (e.g. Amphicotylus , Denazinosuchus , Nannosuchus ).

Most North American specimens referred to Goniopholis have not been evaluated through phylogenetic analysis. ‘ Goniopholis ’ stovalli is included in the phylogenetic analysis of Turner & Buckley (2008), but the resulting topology only places the taxon in a polytomy containing G. simus , Calsoyasuchus , Sunosuchus , and Eutretauranosuchus . In the present analysis, two taxa ( Amphicotylus and Denazinosuchus ) are found to be closely related to the genus Goniopholis (sensu this paper). The inclusion of these North American taxa/ specimens in the genus Goniopholis is misleading. They should be referred provisionally to other previously used names (e.g. Amphicotylus ), or to new generic names. In any case, a definitive statement on their relationships and generic assignment should await detailed revision and description of the material.

Asian genera, according to their affinities, may be preliminarily considered as Sunosuchus or Siamosuchus , but not Goniopolis. From the small range of taxa analysed, current data support the referral of Su. thailandicus to the genus Sunosuchus (as in Buffetaut & Ingavat, 1980), as it has a close and more exclusive relationship with Su. miaoi . The results however, point toward a close relationship between Su. junggarensis and Eutretauranosuchus , which is supported by other phylogenetic results (e.g. Allen, 2007; Lauprasert et al., 2007). Furthermore, Sunosuchus shunanensis Fu et al., 2005 has important morphological differences that may indicate a much more basal position in the clade, a hypothesis yet to be tested through phylogenetic analysis. The taxonomy of the Sunosuchus group appears to be complex, and the internal relationships of the node containing all Sunosuchus and Eutretauranosuchus are yet to be fully resolved. Therefore it seems premature to propose taxonomic amendments for this group. Nonetheless, considering the results of the phylogenetic analysis herein, it seems appropriate to introduce a single nomenclatural change, for ‘ G. ’ phuwiangensis Buffetaut & Ingavat, 1983 . This is important because the taxon does not fit any possible definition of Goniopholis , being more closely related to the Sunosuchus group. Considering the fragmentary nature of the specimen, we prefer to avoid creating a new monospecific genus to accommodate the taxon. Instead, we propose that ‘ Goniopholis ’ phuwiangensis Buffetaut & Ingavat, 1983 is provisionally moved to the genus Sunosuchus until further studies can accurately evaluate the internal relationships of the Sunosuchus group. This taxon is therefore changed to Sunosuchus phuwiangensis ( Buffetaut & Ingavat, 1983) comb. nov., and should not be further referred to the genus Goniopholis .