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Archosaur pelvis evolution, convergences and trends

Sorry for the subject line typo. A link to the data supplements:


---------- Forwarded message ----------
From: Ben Creisler <bcreisler@gmail.com>
Date: Thu, Jul 31, 2014 at 9:28 PM
Subject: Archosaur pelvis evolution, convergences and trends
To: dinosaur@usc.edu

Ben Creisler

A recent paper not yet mentioned:

Masaya Iijima and Yoshitsugu Kobayashi (2014)
Convergences and Trends in the Evolution of the Archosaur Pelvis.
Paleobiology 40(4):608-624
doi: http://dx.doi.org/10.1666/13053

The pelvic structure in non-avian archosaurs plays a key role in
understanding the evolution of terrestrial locomotor patterns because
the pelvis contains major attachment sites for proximal hind limb
musculature. In order to investigate patterns of pelvic evolution in
archosaurs, this study compiled three pelvic indices, as well as
femoral head orientation, for 92 archosaur taxa. With the metrics and
a reconstructed supertree, we examined the correlated evolution of the
pelvis and femur, the correlation among pelvic components, and
temporal trends in the evolution of the pelvis. The result shows that
archosaurs with medially directed femoral heads have more cranially
shifted iliac centroids and more posteriorly rotated pubes than taxa
with anteromedially directed femoral heads. The craniad shift of the
iliac centroid might be correlated to the posterior rotation of pubis.
The pelvic structures of pterosaurs, ornithischians, sauropods, and
avetheropods occupy a different morphospace from basal archosaurs,
pseudosuchians, basal dinosauromorphs, basal theropods, and basal
sauropodomorphs in having more cranially expanded ilia, more
posteriorly rotated pubes, and medially deflected femoral heads. This
may imply that pterosaurs and those derived dinosaurs independently
underwent similar shifts in thigh muscles and locomotion. The
evolutionary model fitting supports the early-burst model for iliac
and pubic metrics in more inclusive archosaur clades, indicating that
larger changes of archosaur pelves occurred in early times of the
clade's history.