Melanorosaurus readi Haughton, 1924 (Dinosauria, Sauropodomorpha) from the Late Triassic of South Africa: osteology and designation of a lectotype

The sauropodiform sauropodomorph dinosaur Melanorosaurus readi Haughton, 1924, from the lower Elliot Formation (Norian) of South Africa, has had a checkered taxonomic history. This is due to the lack of published information on the original syntype material and the use of referred specimens as the primary source of anatomical information on the taxon. Here, we present a revised osteology of Melanorosaurus based solely on the syntype series and argue that the latter includes the remains of a single, associated individual that we designate the lectotype. The species can be diagnosed on the basis of features of the caudal vertebrae and ilium but we restrict the hypodigm to the lectotype pending detailed reassessment of all referred specimens. Melanorosaurus has been used as an external specifier in the definition of Sauropoda, but given the fragmentary nature of the material, its lack of clear ‘sauropod-like’ features, and its phylogenetic lability we suggest that this is no longer appropriate.