Overview
- Sonselasuchus cedrus, a shuvosaurid from Arizona’s Chinle Formation, is formally described by Elliott Armour Smith and Christian A. Sidor in the Journal of Vertebrate Paleontology.
- Forelimb measurements show negative allometry relative to the hindlimb through growth, consistent with a juvenile quadruped becoming a bipedal adult; younger forelimbs were about 75% of hindlimb length, dropping to roughly 50% in larger individuals.
- The Kaye Quarry bonebed at Petrified Forest National Park has yielded over 3,000 fossils in total, including about 950 specimens of S. cedrus representing at least 36 individuals.
- Osteology reveals an ornithomimid-like body plan—long legs, a toothless beak, hollow bones, and a large eye socket—interpreted as convergent evolution on the croc-line.
- Phylogenetic analysis places the new species in an unresolved clade with Effigia okeeffeae and Shuvosaurus inexpectatus, underscoring shuvosaurid diversity in Late Triassic North America.