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The first detailed cranial description of Massospondylus carinatus using a CT scan and 3D digital reconstruction

23 Sep 2013, 14:30

20m

Necsa's Visitor Centre

Oral Presentation Oral Oral Presentation

Speaker

Ms Kimberley Chapelle (ESI Wits)

Description

Massospondylus carinatus Owen, 1854 is a basal sauropodomorph dinosaur from the Late Triassic to Early Jurassic. It was one of the first dinosaurs ever described and is emblematic of the importance of South African palaeontology to the study of dinosaur evolution. Massospondylus was the dominant large herbivore of its time and is represented by an array of well-preserved specimens. Surprisingly, there is a lack of detailed cranial descriptions for this taxon, and this has hampered comparisons with other sauropodomorph taxa. For example, the braincase and vertebrae were described as of 1854, whereas the skull was only briefly described in 2004. In fact, there are no cranial autapomorphies which have been set to clearly differentiate Massospondylus from its sister taxa. Most Massospondylus specimens are preserved in a mudstone matrix that makes preparation of fine-scale skull features difficult, therefore understanding its cranial anatomy requires advanced imaging techniques. The aims of this project were to produce a 3D representation of the skull and braincase of Massospondylus, describe its cranial anatomy (including internal structures) and compare this to the skull of other sauropodomorphs. These data are then used to establish cranial autapomorphies of Massospondylus, test its phylogenetic position by comparing it to related taxa, and form a strong basis for future studies of the growth and development of this important dinosaur taxon. Massospondylus is the only sauropodomorph for which a complete size series is known, therefore using these new data in conjunction with scans of the other skulls could allow for the understanding of brain development and how the skull bones change during growth.