Anomalepis aspinosus

Anomalepis aspinosus is a species of snake in the Anomalepididae family. It is endemic to Peru.The skull and some of its permanently cartilagenous elements, as, for instance, the concha and other parts of the nasal capsule and the trabecule cranii have been studied. The trigeminal musculature and the depressor mandibulae has been observed. The head musculature proved to be different in many several points from Liotyphlops, the other partly investigated Anomalepine. Details on the exits of cranial nerves and the topography of the cranial glands has been studied in order to get a better understanding about the position and origin of the Typhlopoid snakes, which form a quite separate and not too small systematic unit strongly different from other groups of snakes. In order to get an idea of a primitive Typhopoid snake, information about the "aberrant" genera had to be combined with the already known features of the best-known genus, Typhlops; therefore, both Anomalepines had to be studied and compared with Typhlops. It is clear and evident that the Anomalepines are in many cranial characters more primitive than Typhlops, as by the presence of the remnant of the ancestral jugal arch(composed of the postorbital exclusively); by the presence of a big ectopterygoid and a prefrontal not fused with a rigid burrowing snout as in Typhlops. On the other hand, the fusion of the pair of nasals and the formation of a septum nasi osseum as a result of this fusion are features unknown in Typhlops. In Anomalepis, no tabular is found as in Liotyphlops. Typhlops, however, is more primitive in retaining a splenial in a peculiar position sharing with the dentary the symphysis. The peculiar retractor maxillae muscle of Typhlops is replaced by a double-bellied enlarged m. pterygoideus.