Coracoid tubercle explained

The coracoid tubercle is an anatomical feature of the pectoral skeleton in archosaurs, including maniraptoran dinosaurs. It is sometimes called the biceps tubercle. It is also sometimes called the coracoid tuber or biceps tuber.

The coracoid tubercle is a prominent area on the anterior surface of the coracoid, just ventral to the shoulder socket (glenoid). The coracoid tubercle forms the pointed portion in those coracoids described as "flexed". It was previously called the biceps tubercle because it was thought to be the origin of the M.biceps muscle. Makovicky & Sues (1998)^[1] followed Alick Walker (1990)^[2] in asserting that it is, instead, probably the origin of the M. coracobrachialis muscle. Thus, they preferred the term "coracoid tubercle". Norell and Makovicky (1999) followed this precedent and credited Osmolska (1972)^[3] with their precise definition of "coracoid tubercle".^[4]

Notes and References

1. Makovicky, peter, Sues, Hans-Dieter. (1998) "Anatomy and Phylogenetic Relationships of the Theropod Dinosaur Microvenator celer from the Lower Cretaceous of Montana" "American Museum Novitates" no. 3420 27pp. 27 August 1998.
2. Walker, A.D. (1990) "A revision of Sphenosuchus acutus Haughton, a crocodylomorph reptile from the Elliot Formation (Late Triassic or Early Jurassic) of South Africa." "Philosophical Transactions of the Royal Society of London B., Biological Sciences" 330:1-120
3. Osmolska, Halszka, Roniewicz, E., Barsbold, R. (1972) "Results of the Polish-Mongolian Palaeontological Expeditions-PartIV. A new dinosaur, Gallimimus bullatus n. gen. n. sp. (Ornithomimidae) from the Upper Cretaceous of Mongolia". "Palaontologica Polonica" 27:103-143
4. "Important Features of the Dromaeosaurid Skeleton II: Information from Newly Collected Specimens of Velociraptor mongoliensis". "American Museum Novitates" 3282, pp.27 8 December 1999