Suprafamilial relationships within marsupialia: Resolution and discordance from multidisciplinary data

Abstract

Selected characters of the cranioskeletal, dental, neuroanatomical, reproductive, lymphoid, and developmental systems that are known for most or all extant marsupial families are reviewed and analyzed for their abilities to corroborate higher-level hypotheses of suprafamilial relationships among extant marsupials. In addition, relatively conservative nucleotides from the mitochondrial 12S rDNA gene (obtained from the recent study by Springer et al., J. Mammal. Evol. 2, 85-115, 1994) were incorporated into the same character analysis. The ancestral morphotype for each marsupial family and each character was reconstructed, using the reconstructed eutherian and therian morphotypes for outgroup comparisons. In addition, ontogenetic data, stratigraphic position of fossils, and form-functional considerations were used, whenever feasible, to assess character state polarity of anatomical traits. Despite missing data from some families and many genera, this preliminary and modified "total evidence" approach helps to identify several well corroborated higher taxa, including Diprotodontia, Vombatiformes, and Macropodoidea, and it provides modest support for Ameridelphia, Australidelphia, and Syndactyla. An important conclusion is that no single data set is capable of resolving all suprafamilial relationships among marsupials. Suggestions are also presented for future multidisciplinary approaches to help resolve several polychotomies that have remained resistant to phylogenetic analyses of single data sets.

Dispersal, vicariance, and the Late Cretaceous to early tertiary land mammal biogeography from South America to Australia

“…In that articles referred to herein utilize classifications similar to Marshall et al (1990), we continue to follow that classification here. At a more detailed level, Sarich et al (1982) finally laid to rest the perennial resurrection of the question of close phyletic affinities between the Australian thylacine (Tasmanian "wolf") and the extinct borhyaenids of South America [the thylacine is more closely related to extant dasyurids than to extant South American marsupials (see also Krajewski et al, 1992;Luckett, 1994)]. A remaining question, however, concerns the position of the Peramelidae (Australian bandicoots).…”

Earliest evidence of cynodont burrowing

“…However, insufficient ecological data for some putatively basal marsupial species (e.g. Didelphis (McManus 1974)), and the conflict between marsupial phylogenies based on morphological versus molecular characters (Springer et al 1991;Luckett 1994;Szalay 1994), complicate a phylogenetic perspective on burrowing in marsupials. Placental phylogenies based on molecular studies are largely congruent with respect Proc.…”

The geologically oldest dasyurid, from the Miocene of Riversleigh, north‐west Queensland

“…All other attempts, based on, or including, morphological data and inclusive of both American and Australian marsupicarnivore taxa, have been subjective (e.g. Archer 1976b; Marshall et al 1990;Luckett 1994), although parsimony-based methodology has been applied to some groups at lower taxonomic levels (e.g. Reig et al 1987;Muirhead and Wroe 1998).…”

“…An investigation that will re-examine marsupicarnivore relationships using an algorithm-based treatment is in preparation, but this work is well beyond the scope of the present study. The polarity decisions, as well as the interpretation of dasyuromorphian relationships presented below, have been determined subjectively following the methodology of Luckett (1994) and Wroe (1996a), i.e. on the basis of commonality, outgroup comparisons, ontogeny, form function data and stratigraphical position.…”