Australia's iconic emu (Dromaius novaehollandiae novaehollandiae) is the only living representative of its genus, but fossil evidence and reports from early European explorers suggest that three ...island forms (at least two of which were dwarfs) became extinct during the nineteenth century. While one of these—the King Island emu—has been found to be conspecific with Australian mainland emus, little is known about how the other two forms—Kangaroo Island and Tasmanian emus—relate to the others, or even the size of Tasmanian emus. We present a comprehensive genetic and morphological analysis of Dromaius diversity, including data from one of the few definitively genuine Tasmanian emu specimens known. Our genetic analyses suggest that all the island populations represent sub-populations of mainland D. novaehollandiae. Further, the size of island emus and those on the mainland appears to scale linearly with island size but not time since isolation, suggesting that island size—and presumably concomitant limitations on resource availability—may be a more important driver of dwarfism in island emus, though its precise contribution to emu dwarfism remains to be confirmed.
The study of faunal remains from archaeological sites is often complicated by the presence of large numbers of highly fragmented, morphologically unidentifiable bones. In Australia, this is the ...combined result of harsh preservation conditions and frequent scavenging by marsupial carnivores. The collagen fingerprinting method known as zooarchaeology by mass spectrometry (ZooMS) offers a means to address these challenges and improve identification rates of fragmented bones. Here, we present novel ZooMS peptide markers for 24 extant marsupial and monotreme species that allow for genus-level distinctions between these species. We demonstrate the utility of these new peptide markers by using them to taxonomically identify bone fragments from a nineteenth-century colonial-era pearlshell fishery at Bandicoot Bay, Barrow Island. The suite of peptide biomarkers presented in this study, which focus on a range of ecologically and culturally important species, have the potential to significantly amplify the zooarchaeological and paleontological record of Australia.
Lancefield Swamp, south-eastern Australia, was one of the earliest sites to provoke interest in Pleistocene faunal extinctions in Sahul (Pleistocene Australia-New Guinea). The systematic ...investigation of the deposit in the early 1970s identified megafaunal remains dominated by the 100–200 kg kangaroo Macropus giganteus titan. Associated radiocarbon ages indicated that the species was extant until c.30,000 BP, suggesting significant overlap with human settlement of Sahul. This evidence was inconsistent with contemporary models of rapid human-driven extinctions. Instead, researchers inferred ecological tethering of fauna at Lancefield Swamp due to intense drought precipitated localised mass deaths, consistent with Late Pleistocene climatic variability. Later investigations in another part of the swamp, the Mayne Site, remote to the initial investigations, concluded that mass flow disturbed this area, and Electron Spin Resonance (ESR) analyses on megafauna teeth returned wide-ranging ages. To clarify site formation processes and dating of Lancefield Swamp, we excavated new test-pits next to previous trenches in the Classic and Mayne Sites. We compared absolute chronologies for sediments and teeth, sedimentology, palaeo-topography, taphonomy, and macropod age at death across the swamp. Luminescence dating of sediments and ESR analysis of teeth returned ages between c.80,000 and 45,000 years ago. We found no archaeological remains in the bone beds, and evidence of carnivore activity and fluvial action, in the form of reactivated spring flow. The latter disturbed limited parts of the site and substantial areas of the bone beds remained intact. The faunal assemblage is dominated by megafaunal adult Macropus, consistent with mass die-offs due to severe drought. Such droughts appear to have recurred over millennia during the climatic variability of Marine Isotope Stages 4 and 3. These events began tens of millennia before the first appearance of Aboriginal people in Sahul and only the very youngest fossil deposits could be coeval with the earliest human arrivals. Therefore, anthropogenic causes cannot be implicated in most if not all of mass deaths at the site. Climatic and environmental changes were the main factors in site formation and megafauna deaths at Lancefield Swamp.
•Lancefield Swamp contains thousands of megafauna bones, mainly giant macropods.•Our multi-disciplinary analyses show how and when these bones accumulated.•Megafauna died at Lancefield Swamp in mass numbers during severe droughts.•These events started well before humans appeared in Sahul.•Pleistocene climatic variability was a factor in regional megafauna extinctions.
Fossil avian eggshell preserves ancient DNA Oskam, Charlotte L.; Haile, James; McLay, Emma ...
Proceedings of the Royal Society. B, Biological sciences,
07/2010, Volume:
277, Issue:
1690
Journal Article
Peer reviewed
Open access
Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that ...fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful isolation and amplification of DNA from fossil eggshell up to 19 ka old. aDNA was successfully characterized from eggshell obtained from New Zealand (extinct moa and ducks), Madagascar (extinct elephant birds) and Australia (emu and owl). Our data demonstrate excellent preservation of the nucleic acids, evidenced by retrieval of both mitochondrial and nuclear DNA from many of the samples. Using confocal microscopy and quantitative PCR, this study critically evaluates approaches to maximize DNA recovery from powdered eggshell. Our quantitative PCR experiments also demonstrate that moa eggshell has approximately 125 times lower bacterial load than bone, making it a highly suitable substrate for high-throughput sequencing approaches. Importantly, the preservation of DNA in Pleistocene eggshell from Australia and Holocene deposits from Madagascar indicates that eggshell is an excellent substrate for the long-term preservation of DNA in warmer climates. The successful recovery of DNA from this substrate has implications in a number of scientific disciplines; most notably archaeology and palaeontology, where genotypes and/or DNA-based species identifications can add significantly to our understanding of diets, environments, past biodiversity and evolutionary processes.
Abstract
Ancient protein studies have demonstrated their utility for looking at a wide range of evolutionary and historical questions. The majority of palaeoproteomics studies to date have been ...restricted to high latitudes with relatively temperate environments. A better understanding of protein preservation at lower latitudes is critical for disentangling the mechanisms involved in the deep-time survival of ancient proteins, and for broadening the geographical applicability of palaeoproteomics. In this study, we aim to assess the level of collagen preservation in the Australian fossil record. Collagen preservation was systematically examined using a combination of thermal age estimates, Fourier Transform Infrared Spectroscopy, Zooarchaeology by Mass Spectrometry, and protein deamidation calculations. We reveal unexpected subtropical survival of collagen in bones more than 50 thousand years old, showing that protein preservation can exceed chemical predictions of collagen survival in bone. These findings challenge preconceptions concerning the suitability of palaeoproteomics in subtropical Pleistocene environments. We explore potential causes of this unexpected result to identify the underlying mechanisms leading to this exceptional preservation. This study serves as a starting point for the analysis of ancient proteins in other (sub)tropical contexts, and at deeper timescales.
Recent claims for continent wide disappearance of megafauna at 46.5 thousand calendar years ago (ka) in Australia have been used to support a "blitzkrieg" model, which explains extinctions as the ...result of rapid overkill by human colonizers. A number of key sites with megafauna remains that significantly postdate 46.5 ka have been excluded from consideration because of questions regarding their stratigraphic integrity. Of these sites, Cuddie Springs is the only locality in Australia where megafauna and cultural remains are found together in sequential stratigraphic horizons, dated from 36-30 ka. Verifying the stratigraphic associations found here would effectively refute the rapid-overkill model and necessitate reconsideration of the regional impacts of global climatic change on megafauna and humans in the lead up to the last glacial maximum. Here, we present geochemical evidence that demonstrates the coexistence of humans and now-extinct megafaunal species on the Australian continent for a minimum of 15 ka.
The Greater Swan Region is an archaeological study area on the Indian Ocean coast in south-western Australia. It covers the central Swan Coastal Plain and the adjacent part of the formerly emergent ...Rottnest Shelf. Assessment of Aboriginal hunter-gatherer activity throughout this late Quaternary coastal landscape is based on dated records of open-air sites within their environmental settings, informed by historical accounts of mainland subsistence activities. Artefacts flaked from Eocene fossiliferous chert and other stone, identified, in situ, in dated dune soils on the mainland and in palaeosols and Tamala Limestone successions on Rottnest Island, show that during regressive sea levels human groups were distributed across a sand plain reaching from the Darling Scarp 70 km westward across the emergent Rottnest Shelf. On the mainland, open-air site settings near freshwater sources and terrestrial and estuarine habitats give insight into adaptive strategies of Aboriginal occupiers. A similar occupation pattern is proposed for the emergent shelf. Early Holocene records of terrestrial plant species and freshwater microfauna from Barker Swamp on Rottnest Island imply that freshwater sources and terrestrial habitats were comparable to those of the mainland. Further archaeological investigations on the Rottnest Shelf should include extant and former freshwater swamps on Rottnest Island.
The size of the largest marsupial and why it matters Wroe, Stephen; Crowther, Mathew; Dortch, Joe ...
Proceedings of the Royal Society. B, Biological sciences,
02/2004, Volume:
271, Issue:
Suppl 3
Journal Article
Peer reviewed
Open access
We show that at 2786 kg, the largest known marsupial, Diprotodon optatum, was much larger than has previously been suggested. Our results contradict the conclusion that the maximum attainable body ...mass of an Australian marsupial has been constrained by low productivity.
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