This is Tetraceratops insignis, an unusual synapsid from the early Permian of Texas. This is a very interesting animal, and I was happy to finally draw it. It is described from a single and very deformed skull about 9 cm long.
The skull of Tetraceratops is short and high. Its most unusual feature is four bony protrusions, one pair of which was located above the nostrils, and the second - in front of the eyes. These "horns" provided the basis for a name that is much more suitable for a horned dinosaur than a protomammal - "four-horned face". They were made of thick bone and, judging by the texture, were covered with dense skin in life. It is possible that Tetraceratops used them to fight with their relatives or in behavioral demonstrations. Later, another pair of protrusions was found - on angular bones, their purpose is unknown.
The rest of the skull is generally typical of early synapsids. The eye sockets are huge, their owner could be nocturnal. The upper teeth are differentiated: the front pair of massive "incisors", apparently protruding from the mouth in the manner of rodents, stands out. Next comes the diastema, and the rest of the maxillary teeth are generally typical for early amniotes. On the lower jaw, the differentiation is not so pronounced. Tetraceratops was a predator. The structure of its body is unknown, because there is no postcranium.
The classification of Tetraceratops has been the subject of debate. Although initially it was considered an early pelycosaur, later has been popular point of view, as if it was the early therapsid. F. Spindler's revision, published this year, found no reason for this statement. According to Spindler (2020), Tetraceratops was only an early sphenacodont, though unusual.
I decided to do this work on grey paper in order to work with the lighting for which I chose this perspective. I wanted to better show the unusual appearance of Tetraceratops. I hope the result was satisfactory.
EDIT: I was dissatisfied with some detail sand thus did necessary corrections. I also added the black background for better display of light direction. Now I like it.
Black gel ink pen and whitewash on grey paper, 2020.
Anyways jokes aside, the design of Tetraceratops looks really bizarre and interesting.
and, yes I know that Tetraceratops is a synapsid. I was just making a little joke on how the suffix "ceratops" is mainly used for ceratopsians.