Here is an important new paper by my friends and colleagues Sterling Nesbitt and Alan Turner. Where was this paper months back when we had a detailed discussion/disagreement on dinosaur furcula homology in my Age of the Dinosaurs class?
Nesbitt, S.J., Turner, A.H., Spaulding, M., Conrad, J.L., and M. A. Norell. 2009. The theropod furcula. Journal of Morphology early view. DOI: 10.1002/jmor.10724
ABSTRACT - The furcula is a structure formed by the midline fusion of the clavicles. This is the element which is unique to theropods and is important for understanding the link between birds and other theropods. New specimens from basal theropods suggest that the furcula appeared very early in theropod history. We review furcula development, function, and morphology, as well as the anatomical terminology applied to it. Furcular morphology is highly variable in crown-group avians but is rather conserved among nonavian theropods. Here we review, or describe for the first time, the furculae in many nonavian theropods. Furculae occur in nearly all major clades of theropods, as shown by new theropod specimens from the Early Cretaceous of China and a close inspection of previously collected specimens. Informative phylogenetic characters pertaining to the furcula occur throughout Theropoda, though care should be take to consider taphonomic effects when describing furcular morphology.
10 hours ago in Variety of Life