Fred Ruhe
Well-known member
Andrea Cau, Vincent Beyrand, Rinchen Barsbold, KhishigjavTsogtbaatar & Pascal Godefroit, 2021
Unusual pectoral apparatus in a predatory dinosaur resolves avian wishbone homology
Scientific Reports 11: 14722
DOI: https://doi.org/10.1038/s41598-021-94285-3
https://www.nature.com/articles/s41598-021-94285-3
Abstract:
The furcula is a distinctive element of the pectoral skeleton in birds, which strengthens the shoulder region to withstand the rigor of fight. Although its origin among theropod dinosaurs is now well supported, the homology of the furcula relative to the elements of the tetrapod pectoral girdle (i.e., interclavicle vs clavicles) remains controversial. Here, we report the identifcation of the furcula in the birdlike theropod Halszkaraptor escuilliei. The bone is unique among furculae in non-avian dinosaurs in bearing a visceral articular facet in the hypocleideal end firmly joined to and overlapped by the sternal plates, a topographical pattern that supports the primary homology of the furcula with the interclavicle. The transformation of the interclavicle into the furcula in early theropods is correlated to the loss of the clavicles, and reinforced the interconnection between the contralateral scapulocoracoids, while relaxing the bridge between the scapulocoracoids with the sternum. The function of the forelimbs in theropod ancestors shifted from being a component of the locomotory quadrupedal module to an independent module specialized to grasping. The later evolution of novel locomotory modules among maniraptoran theropods, involving the forelimbs, drove the re-acquisition of a tighter connection between the scapulocoracoids and the interclavicle with the sternal complex
Free pdf: https://www.nature.com/articles/s41598-021-94285-3.pdf
Enjoy,
Fred
Unusual pectoral apparatus in a predatory dinosaur resolves avian wishbone homology
Scientific Reports 11: 14722
DOI: https://doi.org/10.1038/s41598-021-94285-3
https://www.nature.com/articles/s41598-021-94285-3
Abstract:
The furcula is a distinctive element of the pectoral skeleton in birds, which strengthens the shoulder region to withstand the rigor of fight. Although its origin among theropod dinosaurs is now well supported, the homology of the furcula relative to the elements of the tetrapod pectoral girdle (i.e., interclavicle vs clavicles) remains controversial. Here, we report the identifcation of the furcula in the birdlike theropod Halszkaraptor escuilliei. The bone is unique among furculae in non-avian dinosaurs in bearing a visceral articular facet in the hypocleideal end firmly joined to and overlapped by the sternal plates, a topographical pattern that supports the primary homology of the furcula with the interclavicle. The transformation of the interclavicle into the furcula in early theropods is correlated to the loss of the clavicles, and reinforced the interconnection between the contralateral scapulocoracoids, while relaxing the bridge between the scapulocoracoids with the sternum. The function of the forelimbs in theropod ancestors shifted from being a component of the locomotory quadrupedal module to an independent module specialized to grasping. The later evolution of novel locomotory modules among maniraptoran theropods, involving the forelimbs, drove the re-acquisition of a tighter connection between the scapulocoracoids and the interclavicle with the sternal complex
Free pdf: https://www.nature.com/articles/s41598-021-94285-3.pdf
Enjoy,
Fred
