Plateosaurus hand motion (free pdf)

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com


A new paper in Palaeontologia Electronica:

Stefan Reiss and Heinrich Mallison (2014)
Motion range of the manus of Plateosaurus engelhardti von Meyer, 1837.
Palaeontologia Electronica 17.1.12A (19p)
doi: palaeo-electronica.org/content/2014/692-plateo-hand
http://palaeo-electronica.org/content/2014/692-plateo-hand

The mode of locomotion of the basal sauropodomorph Plateosaurus
engelhardti, known from numerous finds from the late Triassic of
Central Europe, has been extensively debated. Some early and recent
research results indicate that the forelimb could not play role in
quadrupedal locomotion. Other authors suggested facultative or even
permanent quadrupedality. This would require adaptations of the range
of motion and the stability of the manual digits to the high forces
caused by locomotion. An analysis of the hyperextension capabilities
of the hand can therefore determine if the manus is adapted for
locomotion. This study examines the capabilities of the manus of P.
engelhardti using digital 3D modeling. The motion ranges of the digits
were simulated in a computer-aided engineering (CAE) program, and the
hyperextension capability of the entire manus was tested.

We find that the hand of Plateosaurus was not able to support the
animal during quadrupedal locomotion, but may rather have been a
specialized grasping organ. Therefore, P. engelhardti must have been
an obligate biped.