Massospondylus Skull

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You can find an article here about: "A New Look at Massospondylus carinatus Owen's Skull Based on CT Scans and a Review of Key Sauropodomorpha Features". Massospondylus carinatus is a basal sauropodomorph dinosaur from the early Jurassic Elliot Formation in South Africa. It has been one of the most well-represented fossil dinosaur groups, known from hundreds of specimens including at least 13 complete or nearly complete skulls. Amazingly, the internal anatomy of M. carinatus' skull has never been described using computed tomography (CT) methods. Using CT scans and digital representations, we reconstructed the facial skeleton, braincase, and palate of a complete, undistorted cranium of M. carinatus (BP/1/5241). We described the anatomical features of the cranial bones and compared them to other closely related sauropodomorph groups like Plateosaurus erlenbergiensis, Lufengosaurus huenei, Sarahsaurus aurifontanalis, and Efraasia minor. We identified a set of unique character states in the skull and braincase for M. carinatus that sets it apart from other groups, but these are still tentative due to the lack of comparative sauropodomorph braincase descriptions. Furthermore, we proposed 27 new cranial characters useful for determining relationships among non-sauropodan Sauropodomorpha, deleted five pre-existing characters, and revised the scores of several existing cranial characters to make explicit homology statements. All the characters that we proposed or revised are illustrated. Using parsimony as an optimality criterion, we then tested the relationships of M. carinatus (using BP/1/5241 as a specimen-level exemplar) in our revised phylogenetic data matrix. The scans were conducted using the Wits Microfocus X-ray computed tomography (CT) facility at the Palaeosciences Centre at the University of the Witwatersrand. The scans were digitally segmented using the software VG Studio Max v.2.1 from Volume Graphics in Heidelberg, Germany.