The presence of a furcula in tyrannosaurid theropods, and its phylogenetic and functional implications

The distribution of clavicles (or furculae) within the Dinosauria has been poorly understood, and until recently many workers argued that they were not even present. It is now known that allosaurids, oviraptorids, Segisaurus, and troodontids possessed clavicles. Fused clavicles (furculae) recovered with several recently discovered tyrannosaurid skeletons are described in this paper. A rerun of Bryant and Russell’s (1993) congruence test was conducted against a new and larger tree reflecting new ideas about theropod phylogeny. The results more consistently show that clavicles are primitively present in theropods.