Structure and morphological diversity of dipodoidea mandible (Rodentia, Dipodoidea)

摘要

Seven Dipodoidea mandible morphotypes are distinguished. The differ in the height of coronoid and condyloid processes; the length of angular process; the size of angles and their turns relative to mandible surface; position of masseteric crests; th size of the alveolar tuberculum and the fossa for tempolar muscle. In Sicistinae (morphotype 1) the structure of the mandible is the most generalized and similar to that of murids. Morphotype II (Zapodinae) and morphotype III (Euchoreutinae) differ from morphotype I in the specific structure of angular process. In Dipodinae (morphotype IV) and Cardiocanninae (morphotype V), the mandibles are similar in structure of mandibular ramus and of angular process, but differ in other parameters. Parapodinae (morphotype VI) differ from all other groups in the structure of mandible body and angle. Characteristic features of Allactaginae mandible (morphotype VII) are in the structure of both mandibular ramus and angle. Possible relations between morphotypes are discussed.