Portal de Periódicos da CAPES

The distribution of some basicranial characters within the Marsupialia and a phylogeny of the Phalangeriformes

1989; Taylor & Francis; Volume: 9; Issue: 2 Linguagem: Inglês

10.1080/02724634.1989.10011755

1937-2809

Mark S. Springer, Michael O. Woodburne,

Comparative Animal Anatomy Studies

ABSTRACT Relationships among diprotodontian marsupials have remained enigmatic despite recent work in neontology and paleontology. Thus, the long suspected monophyly of phalangeriform marsupials in not well established. Basicranial anatomy, however, may be useful in elucidating phylogenetic relationships within the Diprotodontia. Specifically, phalangeriform marsupials have a broadened ectotympanic, a tympanic cavity that is firmly surrounded by bone, and an alisphenoid tympanic wing that extends posteriorly to the anterior margin of the paroccipital and/or posterior lacerate foramen. Within the Phalangeriformes, phalangeroids and petauroids exhibit several derived characters not present in the macropodoids. These characters include modifications of the postglenoid process, the external auditory meatus, the ventral postglenoid foramen, and the bones of the auditory region of the skull. Other derived characters, both cranial and dental, argue against the monophyly of a clade containing phalangeroids and petauroids, but are less convincing than those that support their inclusion in a monophyletic group. Finally, there may be strongly adaptive reasons for reorganization of the phalangeriform basicranium.