The comparative serology of Marsupialia, and a classification of marsupials

Abstract

Serological techniques, featuring extensive use of antisera prepared in marsupials, were used to compare some 2000 sera representing about 100 species from all of the families of living marsupials except Thylacinidae. The results were analysed logically and by two methods of numerical taxonomy, one of which generated phenogiams and three-dimensional representations of affinities. The broadest grouping of marsupials contrasts the Australian forms with two equally distinct American groups, the Didelphidae and Caenolestidae. However, Dromiciops probably represents a third American family, the otherwise extinct Microbiotheriidae, which is closest to Didelphidae; but Caluromys is a true didelphid. There are four equally distinct groups of Australian marsupials: Notoryctes, Tarsipes, the remaining Diprotodonta, and Dasyuroidea with Perameloidea. Myrmecobius is closest to the dasyurids, Macrotis is analogously distinct within Perameloidea, and Phascolarctos has its greatest affinities with Lasiorkinus and Vombatus: the latter three genera group together in contrast to Macropodidae and the Phalangeridae of earlier authors. The genera of the latter family comprise three groups no more similar to each other than to Macropodidae, and the various phalangers examined may be arranged in three familial groups: the Burramyidae (Burramys, Cercartetus, Acrobates), the Petauridae (Petaurus, Pseudockeirus, Schoinobates), and the Phalangeridae (Pkalanger, ZYickosurus, Wyulda). The Macropodidae is divided along classical lines (Potoroinae v. Macropodinae), with the genera of macropodines for the most part following the groups indicated by their chromosomal similarities. Phylogenetic inferences were drawn from these data, and a comprehensive classification of marsupials is presented. This classification represents an attempt to integrate the serological data with other information; however, at the highest level, it follows Ride's multiordinal scheme, except that the perameloids are included with didelphoids, dasyuroids, and Notoryctes in Order Polyprotodonta. The classification is thus non-cladistic at this level, but reflects more accurately the serological groupings in distinguishing taxa in the family-group categories.