Data from: Convergences and trends in the evolution of the archosaur pelvis

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.