Comparative anatomy of the lower jaw and dentition of Pseudopus apodus and the interrelationships of species of subfamily Anguinae (Anguimorpha, Anguidae).

The morphology of the lower jaw and teeth of the legless lizard Pseudopus apodus (Anguimorpha, Anguidae, Anguinae) from Eurasia are described in detail and compared with those of other species of the subfamily Anguinae. The lower jaw anatomy of Pseudopus, especially the dentary and teeth, clearly differs from the genera Ophisaurus and Anguis. Even so, Ophisaurus is largely uniform in its lower jaw morphology across species. The teeth of North American Ophisaurus are slender cylinders, the shafts are mesiodistally compressed and bulge lingually; the apices are curved lingually and posteriorly and have weakly developed cutting edges. Southeast Asian and North African Ophisaurus present conical teeth, with broadened bases, apices more distinctly curved lingually and posteriorly, and cutting edges that are distinctly developed. The lingual surfaces of the tooth apices are striated in Ophisaurus and Pseudopus. The lower jaw of Ophisaurus is in many respects similar to that in Anguis, however, the teeth of Anguis are longer and markedly curved posteriorly. The result of the phylogenetic analysis rendered six equally parsimonious trees. Anguis appears in three alternative positions, as the sister taxon to a clade formed by Ophisaurus and Pseudopus, as the sister taxon of Ophisaurus, or as forming a clade with Ophisaurus which is the sister group to Pseudopus.