Epipophyses

Epipophysen ( eng. epipophyses ) are bony outgrowths of the cervical vertebrae in case of dinosaurs and some basal ( original ) birds. These paired appendages are located on the top of the postzygapophyses - those vertebral processes on the back of the vertebrae, the joints with the rearward following vertebra. Their shape varies from small, hill -like elevations up to large, complex built wings. Epipophysen serve the enlargement of the approach surface of various neck muscles - hence large Epipophysen indicate a strong expression of these muscles.

Epipophysen are considered jointly derived character ( synapomorphy ) of the dinosaurs - this feature was so present in the basalsten ( pristine ) dinosaurs, but was absent from the precursors of the dinosaurs, such as Marasuchus or Silesaurus. Although they were a typical feature of most dinosaur groups, they went at various derived ( advanced ) groups of theropods lost due to an increasingly greater curvature of the neck.

Documents

Used literature

• Stephen L. Brusatte: Dinosaur Paleobiology. 1st edition. Wiley, J., New York, NY 2012, ISBN 978-0-470-65658-7, p 14