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Tyrannosaurid necks in feeding behavior



From: Ben Creisler
bcreisler@gmail.com


A special issue of Journal of Zoology on ancient animal behavior. Some
papers were published earlier online

http://onlinelibrary.wiley.com/doi/10.1111/jzo.2014.292.issue-4/issuetoc


This one is new:

E. Snively, A. P. Russell, G. L. Powell, J. M. Theodor andM. J. Ryan (2014)
The role of the neck in the feeding behaviour of the Tyrannosauridae:
inference based on kinematics and muscle function of extant avians.
Journal of Zoology 292(4): 290-303
DOI: 10.1111/jzo.12109
http://onlinelibrary.wiley.com/doi/10.1111/jzo.12109/abstract


Tyrannosaurid necks were strong and powerful instruments for wielding
the jaws during feeding. Hypotheses of tyrannosaurid neck function are
here grounded by observations of neck morphology and function in
extant archosaurs. Respectively derived morphologies in birds,
crocodilians and tyrannosaurids compromise inferences for some
muscles. However, alternate reconstructions indicate that
tyrannosaurid neck muscles combined the robustness of crocodilian
musculature with the functional regionalization seen in birds.
Alternate hypothesized attachments of an avian-style muscle, the M.
complexus, indicate different capacities for head dorsiflexion and
lateroflexion. Electromyography of the M. complexus in chickens
strengthens inferences about its function in both dorsiflexion and
lateroflexion in extinct dinosaurs, and further suggests that it
imparted roll about the longitudinal axis in concert with the actions
of contralateral ventroflexors. Videography of extant raptors reveals
the involvement of the neck when striking at prey and tearing flesh,
and reconstructed tyrannosaurid musculature indicates capacity for
similar neck function during the feeding cycle. As for birds, muscles
originating in the anterior region of the neck likely stabilized the
head by isometric or eccentric contraction as tyrannosaurids (and
other large theropods) tore flesh by rearing back the body through
extension of their hind limbs.