Kubo, T., and M. O. Kubo. 2012. Associated evolution of bipedality and cursoriality among Triassic archosaurs: a phylogenetically controlled evaluation. Paleobiology 38: 474–485. http://www.bioone.org/doi/full/10.1666/11015.1
Bipedalism evolved more than twice among archosaurs, and it is a characteristic
of basal dinosaurs and a prerequisite for avian flight. Nevertheless, the
reasons for the evolution of bipedalism among archosaurs have barely been
investigated. Comparative analysis using phylogenetically independent contrasts
showed a significant correlation between bipedality (relative length of forelimb)
and cursoriality (relative length of metatarsal III) among Triassic archosaurs.
This result indicates that, among Triassic archosaurs, bipeds could run faster
than quadrupeds. Bipedalism is probably an adaptation for cursoriality among
archosaurs, which may explain why bipedalism evolved convergently in the
crocodilian and bird lineages. This result also indicates that the means of acquiring
cursoriality may differ between archosaurs and mammals.
Kurt Gödel's Open World
2 hours ago in The Curious Wavefunction