[dinosaur] Proterosuchus (Early Triassic archosauriform) endocranial anatomy and life habits

Ben Creisler
[email protected]

A new paper:


Emily E. Brown,  Richard J. Butler,  Martín D. Ezcurra,  Bhart‐Anjan S.
Bhullar  & Stephan Lautenschlager (2019)
Endocranial anatomy and life habits of the Early Triassic archosauriform
Proterosuchus fergusi.
Palaeontology (advance online publication)
doi: https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.1111_pala.12454&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=1hpVJ_nzUh29dvxAP3O8-CYAEUIBPBjE5wuiZIdSolc&s=mS2ex9q-EwdIrqgcFUA8liAiea4vkXBzMAi3qI6_9mE&e= 
https://urldefense.proofpoint.com/v2/url?u=https-3A__onlinelibrary.wiley.com_doi_full_10.1111_pala.12454&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=1hpVJ_nzUh29dvxAP3O8-CYAEUIBPBjE5wuiZIdSolc&s=uC32ySAPAEiCUiulmVMVza8ay9p2j9igRlDR97L7C4k&e= 

Data archiving statement:
Original CT data for RC 846 are archived at Yale University and are
available from B‐ASB on request. Original CT data for SNSB‐BSPG 1934 VIII
514 are available in the Dryad Digital Repository:
https://urldefense.proofpoint.com/v2/url?u=https-3A__doi.org_10.5061_dryad.p6t3341&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=1hpVJ_nzUh29dvxAP3O8-CYAEUIBPBjE5wuiZIdSolc&s=0LMIcf-m_VpwnD-xyHMwQPVYztA_Kj9FQitVUmvkny0&e= 


Proterosuchids are an important group of carnivorous basal archosauriforms
characterized by a bizarre and enigmatic downturned premaxilla that
overhangs the lower jaw. They are particularly significant because they
radiated in the immediate aftermath of the Permian–Triassic mass extinction
and represent one of the best known ‘disaster taxa’ following that event.
While traditionally considered to be semi‐aquatic, recent histological
studies and geological data have suggested that it is more likely that they
inhabited terrestrial environments. By using computed tomographic (CT)
data, we virtually reconstruct the brain endocast and endosseous labyrinths
of two adult specimens of Proterosuchus fergusi from the earliest Triassic
of South Africa, in an attempt to understand its life habits within the
context of basal archosauriform evolution. Endocasts reveal that the brain
cavity is tubular in shape and the endosseous labyrinths are highly
pyramidal. The angle of the lateral semicircular canal suggests that P.
fergusi naturally held its head upwards ~17°, while the length of the
cochlear duct suggests its auditory abilities were specialized towards
low‐frequency sounds. Furthermore, beam theory analysis suggests that the
rostrum of P. fergusi is highly resistant to both bending and torsion when
compared to modern crocodilians, although this resistance is neither
enhanced nor reduced by the overhanging premaxilla. Comparative anatomical
analyses suggest P. fergusi was probably a semi‐aquatic, generalist apex
predator capable of surviving the harsh environmental perturbations of the
Early Triassic.