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Aetosaurs made Brachychirotherium footprints
From: Ben Creisler
bscreisler@yahoo.com
A another new paper:
Spencer G. Lucas & Andrew B. Heckert (2011)
Late Triassic Aetosaurs as the Trackmaker of the Tetrapod Footprint Ichnotaxon
Brachychirotherium.
Ichnos 8(4): 197-208
DOI:10.1080/10420940.2011.632456
http://www.tandfonline.com/doi/abs/10.1080/10420940.2011.632456
Abstract
Brachychirotherium is the common ichnogenus of Late Triassic chirothere
footprints well known from western Europe, North America, Argentina and South
Africa. Although it has long been agreed by most workers that the trackmaker of
Brachychirotherium was a derived crurotarsan archosaur, the trackmaker has been
identified as either a rauisuchian or an aetosaur, and some workers attribute
it to a primitive crocodylomorph (sphenosuchian). New knowledge of the
osteology of the manus and pes of a large aetosaur, Typothorax coccinarum,
indicates a close correspondence between the manus and pes structure of
aetosaurs and the morphology of Brachychirotherium. Furthermore, functional
analysis of complete skeletons indicates aetosaurs plausibly placed their feet
in the narrow gauge, nearly the overstepped walk characteristic of
Brachychirotherium. Brachychirotherium and aetosaurs have matched
distributions, that is, they were Pangea-wide during the Late Triassic.
The manus and pes morphology of rauisuchians and early crocodylomorphs
(sphenosuchians) deviate from Brachychirotherium footprint morphology in key
features, thus excluding their identification as trackmakers. Aetosaurs made
Brachychirotherium footprints.