Emydops
Encyclopedia
Emydops is an extinct genus of dicynodont
therapsid from the Permian
of South Africa
. Emydops was first named by South African paleontologist Robert Broom
in 1912 when he described Emydops minor. In the following years, the genus grew to include thirteen species. Many of these species were erected on the basis of differences in the teeth and the positioning of the frontal
and parietal bone
s. A 2008 study narrowed Emydops down to two species, E. arctatus (first described by English paleontologist Richard Owen
as Kistecephalus arctatus in 1876) and the newly described E. oweni.
Both species of Emydops are small. The skull of Emydops was 5 cm (2 in) long. Tusks are present in most skulls, but some lack them. The eye sockets are positioned far forward in the skull and face somewhat forward and upward. A wide area on the lower jaw called the lateral dentary shelf is another distinguishing feature of the genus. The temporal regions behind the eyes are large, and the back of the skull is wide and square-shaped. The holotype
specimen of E. oweni is unusual in that it has two pairs of tusks. The second pair of tusks is not seen in any other dicynodont, and is a feature unique to the specimen. The extra tusks are considered a pathological feature; they are thought to have been the result of a mutation in the individual and are not considered a defining characteristic of the species.
Dicynodont
Dicynodontia is a taxon of anomodont therapsids or mammal-like reptiles. Dicynodonts were small to large herbivorous animals with two tusks, hence their name, which means 'two dog tooth'...
therapsid from the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
of South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
. Emydops was first named by South African paleontologist Robert Broom
Robert Broom
Professor Robert Broom was a Scottish South African doctor and paleontologist. He qualified as a medical practitioner in 1895 and received his DSc in 1905 from the University of Glasgow...
in 1912 when he described Emydops minor. In the following years, the genus grew to include thirteen species. Many of these species were erected on the basis of differences in the teeth and the positioning of the frontal
Frontal bone
The frontal bone is a bone in the human skull that resembles a cockleshell in form, and consists of two portions:* a vertical portion, the squama frontalis, corresponding with the region of the forehead....
and parietal bone
Parietal bone
The parietal bones are bones in the human skull which, when joined together, form the sides and roof of the cranium. Each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named from the Latin pariet-, wall....
s. A 2008 study narrowed Emydops down to two species, E. arctatus (first described by English paleontologist Richard Owen
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
as Kistecephalus arctatus in 1876) and the newly described E. oweni.
Both species of Emydops are small. The skull of Emydops was 5 cm (2 in) long. Tusks are present in most skulls, but some lack them. The eye sockets are positioned far forward in the skull and face somewhat forward and upward. A wide area on the lower jaw called the lateral dentary shelf is another distinguishing feature of the genus. The temporal regions behind the eyes are large, and the back of the skull is wide and square-shaped. The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
specimen of E. oweni is unusual in that it has two pairs of tusks. The second pair of tusks is not seen in any other dicynodont, and is a feature unique to the specimen. The extra tusks are considered a pathological feature; they are thought to have been the result of a mutation in the individual and are not considered a defining characteristic of the species.