Sminthopsinae

Abstract: Multiple mitochondrial and nuclear gene sequences reveal substantial genetic variation within the dasyurid marsupial genus Planigale, suggesting greater taxonomic diversity than is currently recognised. To further investigate planigale relationships 116 new mitochondrial and nuclear gene sequences, including 16 new specimens, were added to our database. We confirm the presence of an unrecognised species (Planigale ‘species 1’) limited to the Pilbara region of Western Australia and suggest that the ‘Mt Tom Price’ animals may be closely related to Planigale ingrami subtilissima. We also confirm that at least four distinct genetic lineages make up what is currently recognised as P. maculata. This complex of closely related taxa represents a radiation of sibling species rather than a single, genetically diverse one. Three of these lineages (M1 M2, M3 and M4) are distributed sympatrically across the Top End of Australia and one (M5 = P. maculata sensu stricto) is localised to the eastern coast of Australia. Within the Planigale ingrami complex, Planigale ‘Mt Tom Price’ (lineage Ing. 1) occurs in the Pilbara in sympatry with Planigale ‘species 1’ and lineage Ing. 2 is found in the Northern Territory in sympatry with species of the P. maculata complex. There is thus a plethora of northern Australian planigales, many of which are formally undescribed and whose geographic ranges require careful re-evaluation.

Abstract: Sminthopsis is the most speciose genus of living dasyurid marsupials and, along with its close relatives Antechinomys and Ningaui, constitutes the clade Sminthopsini. Phylogenetic relationships among the 23 species in this clade have been the subject of much morphological and molecular investigation, including a recent integration of penis morphology (in Sminthopsis) with molecular systematics. Several phylogenetic issues remain open, however, including the monophyly of Sminthopsis and branching order among early sminthopsin lineages. In this study, we revisit sminthopsin systematics with an expanded molecular data set, including new DNA sequences from mitochondrial (valine transfer-RNA and 16S ribosomal RNA) and nuclear (interphotoreceptor retinoid binding protein and beta-fibrinogen) loci, along with previously published sequences of cytochrome b, 12S ribosomal RNA, control region, and protamine P1. Our results again fail to establish the monophyly of Sminthopsis, but do provide a clearer resolution of early sminthopsin branching. Specifically, our phylogeny suggests three major groups of Sminthopsis species: S. longicaudata (perhaps the sister of Antechinomys); the Macroura species group of previous authors (S. crassicaudata, S. macroura, S. virginiae, S. douglasi, and S. bindi); and the remaining 13 species allied with the Murina species group. Our results depart from previous molecular findings by reuniting S. ooldea with the Murina group, while resolving S. psammophila as sister to the hairy-footed dunnarts (S. hirtipes and S. youngsoni). We suggest that this conflict traces to anomalous phylogenetic signal in previously published cytochrome b sequences. Penis morphology maps reasonably well onto our phylogeny, requiring parallel origination of only one of the ten morphotypes described for Sminthopsis.

Abstract: Archer provided the most recent and comprehensive suprageneric classification of dasyurid marsupials. Five extant subfamilies, two with constituent tribes, were recognized on the basis of morphological, serological, and allozyme data. Phylogenetic relationships among these groups, however, were totally unresolved. Subsequent molecular studies suggested that the endemic New Guinean subfamilies Muricinae and Phascolosoricinae are parts of larger Australian clades. Our objective in this study was to test the monophyly of Archer's seven groups and estimate relationships among them using DNA sequences from the mitochondrial cytochromeb (cyt-b) gene. We report 657 bp ofcyt-b from 32 dasyuroid species. Phylogenetic analysis of these data leads to the following conclusions: (1) muricines form a clade within Phascogalinae that includes endemic New GuineanAntechinus species; (2) the two genera of Phascolosoricinae are part of a more inclusive Dasyurinae; (3) Sminthopsinae is monophyletic, but the tribes Sminthopsini and Planigalini are not; and (4) the dasyurine tribes Dasyurini and Parantechini are probably not monophyletic. Relationships among Sminthopsinae, Dasyurinae (including phascolosoricines), and Phascogalinae (including muricines) remain unresolved.