Epipophyses
The epipophyses are bony projections of the cervical vertebrae found in dinosaurs and some fossil basal birds.[1] These paired processes sit above the postzygapophyses on the rear of the vertebral neural arch.[1] Their morphology is variable and ranges from small, simple, hill-like elevations to large, complex, winglike projections.[1] Epipophyses provided large attachment areas for several neck muscles; large epipophyses are therefore indicative of a strong neck musculature.[1]
The presence of epipophyses is a synapomorphy (distinguishing feature) of the group Dinosauria.[1] Epipophyses were present in the basal-most dinosaurs, but absent in closely related ancestors of this group like Marasuchus and Silesaurus.[1] They were typical for most dinosaur lineages; however, they became lost in several derived theropod lineages in the wake of an increasingly S-shaped curvature of the neck.[1][2]
References
- ^ a b c d e f g Brusatte, Stephen L. (2012). Dinosaur Paleobiology (1. ed.). New York: Wiley, J. p. 14. ISBN 978-0-470-65658-7.
- ^ Currie, Philip J. (1997). "Theropoda". Encyclopedia of dinosaurs. Acad. Press. p. 734. ISBN 0-12-226810-5.
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