An emerging consensus in the evolution, phylogeny, and systematics of marsupials and their fossil relatives (Metatheria)

Marsupials and their fossil relatives, which collectively comprise Metatheria, have been of scientific interest for centuries, with many aspects of their evolution and systematics subject to intense research and debate. Here, we review progress over the last 25 years, which has included the description of many new species (modern and fossil), and major improvements in understanding of their phylogenetic relationships, as well as the overall evolutionary history and biogeography of Marsupialia (crown-clade) and Metatheria (total-clade). Significant advances have included the deployment of increasingly sophisticated molecular, morphological, and total evidence analyses, which have resolved most previously disputed relationships among and within the modern marsupial orders. A broad systematic consensus is now emerging, although several major areas of contention remain, particularly among fossil metatherians. New modern species continue to be described at an impressive rate, with almost 50 named in the last 25 years, and many more await discovery. There has also been an explosion in the discovery and description of fossil marsupials and non-marsupial metatherians (~270 species), principally from Australasia and the Americas but also from Antarctica, Europe, and Asia. Most are represented by dental specimens only, but some consist of complete and well-preserved material, which has led to major improvements in our understanding of the evolution of cranial and postcranial morphology. Improvements in the fossil record and advances in methods for inferring divergence times have helped clarify when and where key events occurred in metatherian evolution, and the patterns of subclade diversification. We also have improved understanding of biogeographical relationships among metatherians on different landmasses. Despite enormous progress, numerous key uncertainties remain due to major gaps in the fossil record (e.g., Antarctica, Late Cretaceous, and early Paleogene of Australia) and a comparative lack of studies that directly combine molecular and fossil data. Future advances will largely depend on improvements in the fossil record and studies that better integrate neontological and paleontological evidence

The importance of appropriate taxonomy in Australian mammalogy

The use of correct taxonomy to describe and name the earth's biodiversity is fundamental to conservation and management. However, there are issues that need to be overcome to ensure that the described taxa and their scientific names are both appropriate and widely adopted. Obstacles to this include the use of different species definitions, taxonomic instability due to accumulation of additional specimens in analyses and the progression of science that allows better resolution of species boundaries, and the inappropriate description and naming of new taxa without adequate scientific basis in self-published journals (known as 'taxonomic vandalism'). In an effort to manage taxonomic instability, the Australasian Mammal Taxonomy Consortium (AMTC), an affiliated body of the Australian Mammal Society, has developed several tools that include: (1) a standardised list of Australian mammal common and scientific names; (2) recommendations for information that should be included in published species descriptions; and (3) support for the publication of aspidonyms (i.e. a scientifically acceptable name proposed to overwrite a pre-existing unscientific name). This review discusses these issues, reaffirms the foundations for appropriate taxonomic research, and provides guidelines for those publishing taxonomic research on Australian mammals

Ancient DNA Elucidates the Controversy about the Flightless Island Hens (Gallinula sp.) of Tristan da Cunha

A persistent controversy surrounds the flightless island hen of Tristan da Cunha, Gallinula nesiotis. Some believe that it became extinct by the end of the 19th century. Others suppose that it still inhabits Tristan. There is no consensus about Gallinula comeri, the name introduced for the flightless moorhen from the nearby island of Gough. On the basis of DNA sequencing of both recently collected and historical material, we conclude that G. nesiotis and G. comeri are different taxa, that G. nesiotis indeed became extinct, and that G. comeri now inhabits both islands. This study confirms that among gallinules seemingly radical adaptations (such as the loss of flight) can readily evolve in parallel on different islands, while conspicuous changes in other morphological characters fail to occur

Evolution: the evolutionary rat race in New Guinea and Australia

A new molecular phylogeny of a remarkable radiation of New Guinean and Australian rodents indicates multiple transitions between biomes and biogeographical regions within the group, and suggests that a key role was played by the geological history of New Guinea

A Significant Range Extension Of The Purple-Necked Petrogale Purpureicollis Rockwallaby

IN 1982, the Queensland subspecies of the blackfooted rock-wallaby Petrogale lateralis purpureicollis was reported to occur around Mt Isa and south to around Dajarra (Briscoe et al. 1982). During 1991, the known range of this taxon was extended 300 km to the north-west when an adult female P. l. purpureicollis was collected from ?Ridgepole Waterhole? in the Musselbrook Resource Reserve near Lawn Hill National Park (Eldridge et al. 1993). In 1994 the range was further extended when P. l. purpureicollis was recorded from the Constance Ranges and the upper reaches of Stockyard and Elizabeth Creeks; around the town of Cloncurry and the following distances from the town: 85 km north west; 60 and 87 km west; 4, 23, 28 and 35 km south and 15 km east (Bell et al. 1995). Approaches by the Cannington Mining operation to the southwest of McKinley in October 1999 to confirm the presence of rock-wallabies on nearby Glenholme Station established the presence of P. l. purpureicollis; a 75 km range extension to the south-east.</jats:p