<i>Purranisaurus potens</i> Rusconi, an enigmatic metriorhynchid from the Late Jurassic–Early Cretaceous of the Neuquén Basin

ABSTRACTThe Tithonian record from northwestern Patagonia (Neuquén Basin) documents a complete succession of lower, middle, and late Tithonian marine reptiles. From the late Tithonian–early Berriasian of Patagonia, three marine crocodyliforms have been recorded: <i>Dakosaurus andiniensis</i>, <i>Cricosaurus araucanensis</i>, and <i>Purranisaurus potens</i>. Although <i>P. potens</i> includes the first metriorhynchid skull described from Patagonia, no detailed description and/or illustrations have been published. Since the mid-20th century, several authors have discussed the validity of <i>P. potens</i>. Recent preparation of the type material allowed a detailed description as well as exploration of its phylogenetic relationships. We consider <i>P. potens</i> as a valid taxon characterized by a unique combination of characters, such as medial and posterolateral processes of the frontal forming an angle of 60°; supratemporal fossae reaching the minimum interorbital distance, with the dorsal margin of the supratemporal arch being slightly concave in lateral view; thin bony lamina projecting from the lateral and medial alveolar margins of the maxilla; occipital surface ventral to occipital condyle parallel to transverse plane of skull; well-developed crest that extends along the entire height of the supraoccipital; and orbital process of the quadrate very conspicuous and acute, horizontal, and without bony attachment. Phylogenetic analysis recovers <i>P. potens</i> as deeply nested within Geosaurini and, contrary to previous proposals, not closely related to ‘<i>Metriorhynchus</i>’ <i>casamiquelai</i> and ‘<i>M.</i>’ <i>westermanni</i>. Internal relationships within Geosaurini are unresolved. <i>Purranisaurus</i>, as a monotypic genus, is restricted to the late Tithonian–early Berriasian.http://zoobank.org/urn:lsid:zoobank.org:pub:CDB288F2-087C-4E19-A897-8AB94BD60EC2SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP