Epoccipital

The Epoccipitalia are bones that are found in the neck plate of dinosaurs from the group of Ceratopsidae. These bones line the plate boundary and are responsible for its wavy appearance. The name Epoccipitale is misleading because these bones are not associated with the occipital of the skull. Instead, they sit on the plate forming bones of the skull roof, the shed and the parietal bone. Epoccipitalia were probably present in all Ceratopsiden, with Zuniceratops as a possible exception. The term Epoccipitale ( gr έπί (epi ) for " at ", " to" and Latin occipitium for " occipital ", " mind " ) was coined in 1889 by the famous paleontologist Othniel Charles Marsh.

Epoccipitalia begin as separate bones formed by intramembranous ossification, but merge in adult animals with the shed or the parietal bone. These bones are very variable in different species of Ceratopsidae. In Ceratopsiden with short plate ( Chasmosaurinae ) the Epoccipitalia were generally more triangular with a broad base - a well-known example is the saw-tooth plate edge of the Triceratops. When representatives with long plate ( Centrosaurinae ), however, they were elliptical with a narrower base. Especially with penny Pink urines as Centrosaurus, Pachyrhinosaurus and Styracosaurus these bones were long and spike- or hook-shaped, depending on the type they vary in number, shape and orientation. This includes Epoccipitalia to the most important diagnostic features ( distinguishing features ) within the Ceratopsidae.

The function of this bone was probably a visual - they were probably the display or for species recognition.