A new neosuchian crocodyliform from the Lower Cretaceous (Aptian–Albian) Holly Creek Formation of southwest Arkansas and its implications on the relationships of Goniopholididae

A new species of neosuchian crocodyliform, <i>Paarthurnax holliensis</i> gen. et sp. nov., is herein described based on a nearly complete skull from the Lower Cretaceous (Aptian–Albian) Holly Creek Formation of southwest Arkansas. This locality contains a wide array of semiaquatic, aquatic, and terrestrial vertebrate body and trace fossils. This new taxon is notable for having a ventrally offset premaxillary tooth row, maxillary groove, transverse interorbital crest, elongate anterolateral process of the postorbital, transversely flattened postorbital bar, large sub-rectangular transverse ellipsoid supratemporal fenestrae, and a laterally opened cranioquadrate passage. Its overall morphology is similar to that of the putative goniopholidid <i>Denazinosuchus kirtlandicus</i> from the Campanian Kirtland Formation of New Mexico, though unlike <i>D. kirtlandicus</i> the new form bears a palatal premaxilla-maxilla suture posteromedially directed on its lateral half and anteromedially directed along its medial region, a more tapered anterior projection of the frontal, and transverse sub-rectangular supratemporal fenestrae. It shares features typically associated with goniopholidids, such as a transverse interorbital crest and a perinarial crest. However, it also shares anterior and posterior rami of jugal comparable in depth, a rod-shaped jugal, and a frontal separated medially from the orbital margin with paluxysuchids. Phylogenetic analyses recover <i>Paarthurnax holliensis</i> as sister to <i>D. kirtlandicus</i>, both falling out as derived goniopholidids. Intriguingly, paluxysuchids are recovered in a derived position within Goniopholididae. This tree topology challenges long-held assumptions about the status and distribution of Goniopholididae, which may have a more expansive distribution in the Cretaceous of North America than previously believed.