An Enigmatic Neodiapsid Reptile from the Middle Triassic of England

Abstract

ABSTRACT The fossil record of early diapsids is sparse, specimens are uncommon and often incomplete, and phylogenetic relationships are hard to determine. A new taxon of early diapsid, Feralisaurus corami from the Middle Triassic of Devon, south-western England, is here named and described from an incomplete but mostly articulated skeleton, comprising skull, vertebrae, pectoral girdle, ribs, and the right forelimb. CT scanning and the resultant 3D model of the skeleton reveal anatomical details otherwise buried in the sandstone matrix. This new diapsid is characterized by a plesiomorphically high maxilla without a prominent nasal process, a quadrate with a lateral conch, a low jugal with small posterior process, conical teeth with pleurodont implantation, a high coronoid process, notochordal vertebrae, a long humerus with an entepicondylar foramen, rod-like clavicles, a ‘T’-shaped interclavicle, and a ventrolateral process of the scapulocoracoid. Phylogenetic analyses, although showing generalized weak support, retrieved Feralisaurus within Neodiapsida or stem-group Lepidosauromorpha: its morphology supports the latter hypothesis. This specimen adds to our knowledge of the early diversification of Lepidosauromorpha and of English Middle Triassic terrestrial faunas.