A new sauropodiform from the Early Jurassic of Antarctica

Abstract

Here, I describe the cranial anatomy of a new species of basal sauropodomorph from the Early Jurassic of Antarctica. This new specimen, FMNH PR 3051, is a juvenile and was collected from the lower Hanson Formation on Mt. Kirkpatrick and includes the only cranial remains of a sauropodomorph from that continent. Only one other basal sauropodomorph, Glacialisaurus hammeri, is currently described from Antarctica, but differs from FMNH PR 3051 in femoral anatomy. The skull is mostly complete apart from missing the posterodorsal margin but is mediolaterally compressed and sheared obliquely. We used µCT scans to create a digital model of each preserved skull bone. Phylogenetic analysis suggest that FMNH PR 3051 is sister to the two Eucnemesaurus species. The phylogeny was used in a biogeographic analysis to determine the historical pathway of sauropodomorphs. FMNH PR 3051 and Glacialisaurus both have parallel biogeographic pathways with ancestral ranges originating in South Africa.