Taxonomy, taphonomy, and biostratigraphic significance of a basal sauropodomorph from the lower elliot formation, Eastern Cape, South Africa

Abstract

South Africa's lower Elliot Formation is notably depauperate in fossils relative to the upper strata. These lower layers, however, are important because they preserve Triassic deposits leading up to a mass extinction event at the Triassic-Jurassic boundary. A new, associated skeleton of a single specimen of basal sauropodomorph recently collected from the lower Elliot Formation represents an extremely rare find from this stratum. This project investigates the systematic position, taphonomy, and stratigraphic context of this specimen through anatomical description, phylogenetic systematics, and sedimentological interpretation. This dissertation shows that the specimen was preserved in a sequence of low-energy stream deposits and overbank/oxbow lakes suggestive of a local death instead of one of transportation. The new specimen represents a new species that is part of a small clade of specimens referred to "Melanorosaurus". However, due to poor provenance data and poor association within the syntype and referred material calls into question the validity of "Melanorosaurus". This clade, and the taxa within it, require taxonomic revision.