A new name for old bones: A reassessment of Early Jurassic theropod remains from Dorset, England

Among the many terrestrial vertebrate specimens that have been recovered from there are two partial yet distinctive theropodan hindlimbs that are not currently assigned to any recognised, valid taxon. Originally this material was referred to the early armoured ornithischian taxon Scelidosaurus harrisonii, which had also been recovered from a Lower Jurassic Formation in Southern England. However, this error in assignment was soon realised and corrected in subsequent works, and the material in question reclassified as an indeterminate theropod. More recent works have suggested possible neotheropod or even tetanuran affinities for at least some of this material, but no consensus has yet been reached about its true phylogenetic and taxonomic affinities. The material has never been formally named, even though the material does appear to display a distinct combination of anatomical characteristics. As one of the earliest known Jurassic representatives of Theropoda, understanding this material is important for clarifying the picture of early theropod evolution and biogeographic distribution. This study re-appraises the two specimens, compares, and contrasts them with other known Triassic and Early Jurassic theropods, and tests their possible phylogenetic affinities using three different anatomical datasets: two that are heavily theropod focused and one more general early dinosaur focused. The results of these analyses, in combination with the anatomical comparisons presented herein, suggest that this fragmentary material could represent a distinct, early occurring, and early branching averostran neotheropod. A new genus and species are thus erected for the material.