Moschorhinus was a large carnivore, reaching in total body length and weighing . The skull is similar to that of the Gorgonopsids, with large
temporal fenestrae (three in total as a synapsid) and a convexly bowed
palate. The skull ranged in size to comparable to a
monitor lizard, to those of a lion. They possess a characteristically short, broad snout. They possess a pair of prominently long
incisors, similar to the
canines of
saber toothed cats. Lateral view of
Moschorhinus jaw, showing range of motion necessary for such large incisors, and upper palatal fenestrae of snout. (From van Valkenburgh and Jenkins, 2002).
Skull roof Tracing the roof of the skull,
Moschorhinus possesses small
prefrontal bones above the eyes, followed by large, widened frontal bones. The
parietals form a narrow
sagittal crest along the midline of the skull, which houses a very basic
pineal foramen.
Eye sockets The
lacrimal bone is larger than the reduced prefrontal, and forms the majority of the
eye socket. The lacrimal has a bony boss (a rounded knob) on the orbit, and a large foramen towards its inner side. The lower edge of the eye socket is formed the
jugal and maxillary bones. The jugal ends at the eye socket, and is not convex, as in several later therocephalians.
Palate Overall, the palate is convex, with a broad, triangular vomer, with paired tubercles, rounded projections pointing ventrally, similar to other akidnognathids. The
palatine bones (forming the back of the roof of the mouth) are enlarged and thick, especially on their outer edges where they are joined to the maxilla. On their inner edges, the palatines are joined to the pterygoid and
vomer on the nose, forming part of the circumference of the
nasal cavity. Between the palatine and maxilla, just behind the canines, are large foramens, presumably to allow for nerves. A slanting ridge along the middle of the palatine presumably supported a soft palate, which allowed air to travel between the nose and the lungs. The sabers require the mouth to open widely for use, making feeding difficult. The closely related
Promoschorhynchus shows stiff folds (
choanal crest) on the border of the nasal passage and the throat, used to keep it open and to allow for breathing while eating. The development of a secondary palate in the skull gradually evolved in therocephalians, and the choanal crest is featured in all later therocephalians. ==Paleobiology==