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Trilophosaurus - climber?
Spielmann, J.A., Heckert, A.B. and Lucas, S.G. (2005). The Late Triassic
archosauromorph _Trilophosaurus_ as an arboreal climber. Rivista Italiana
di Paleontologia e Stratigrafia 111 (3): 395-412.
Abstract: "Two species of the unusual archosauromorph _Trilophosaurus_, _T.
buettneri_ Case and _T. jacobsi_ Murry, are known from diverse localities in
the Upper Triassic Chinle Group in the southwestern USA. Both species
likely occupied similar ecological niches, based on morphological
similarities in the postcrania, which are essentially identical.
_Trilophosaurus_ occurrences in the Chinle Group are relatively rare, but
individual sites are exceptionally rich, suggesting that _Trilophosaurus_
lived in a different paleoenvironment than more typical Chinle vertebrates,
which lived in or near streams (phytosaurs, metoposaurs) or on floodplains
(aetosaurs, rauisuchians, and dinosaurs). Two potential interpretations are
that _Trilophosaurus_ was either an arboreal climber or a fossorial digger.
However, the gross skeletal features of _Trilophosaurus_ are not compatible
with a fossorial mode of life: the limbo are too long and gracile, proximal
limb elements are longer than distal ones, and the claws are laterally
compressed, not transversely broadened. The intermittent study of
_Trilophosaurus_ has caused the theory of it being arboreal, originally
proposed by Gregory, to receive little mention in subsequent studies. We
reexamined the functional morphology of _Trilophosaurus_ using a qualitative
functional morphological analysis of the skeleton, a quantitative
examination of claw curvature, and a quantitative examination of manus/trunk
and pes/ trunk ratios. Claw morphology of _Trilophosaurus_ shows
similarities to the arboreal drepanosaurs _Drepanosaurus_ and
_Megalancosaurus_. Our analysis provides ample evidence to suggest that
_Trilophosaurus_ was arboreal."
I haven't seen the actual article yet. If somebody wants to throw a pdf of
this article my way, I'd be most appreciative.