Shifting faunal baselines through the Quaternary revealed by cave fossils of eastern Australia

Abstract

Fossils from caves in the Manning Karst Region, New South Wales, Australia have long been known, but until now have never been assessed for their palaeontological significance. Here, we report on late Quaternary faunal records from eight caves in the region. Extinct Pleistocene megafaunal taxa are recognised in two systems and include giant echidnas (Tachyglossidae gen. et sp. indet.), devils (Sarcophilus laniarius), koalas (Phascolarctos stirtoni), marsupial ‘lions’ (Thylacoleo carnifex), and kangaroos (Macropus giganteus titan). Some caves contain skeletal remains of introduced exotics such as sheep and dogs, but also provide a rich record of small-bodied native species including Eastern Bettongs (Bettongia gaimardi), Eastern Chestnut Mice (Pseudomys gracilicaudatus), and White-footed Rabbit Rats (Conilurus albipes). These endemics are either locally extirpated or have suffered total extinction in the historic period. Their skeletal and dental remains were recorded as unmineralised surface specimens in the caves, indicating that they are recent in age. Extant populations have never been recorded locally, thus, their probable loss from the region in historic times had gone unnoticed in the absence of palaeo-evidence. Our findings suggest that the supposed habitat tolerances of such species have been substantially underestimated. It is highly likely that modern populations have suffered niche contraction since the time of European colonisation of the continent. The local extirpations of several species of digging mammal has likely led to decreased functionality of the current ecosystem.

Late Quaternary fossil vertebrates of the Broken River karst area, northern Queensland, Australia

“…It is possible that they were present but were decimated rapidly and never recorded in modern ecological surveys of the area. Similar extirpation records for small-bodied mammal species have been noted elsewhere in Australia (e.g., Fusco et al, 2016;Price et al, 2019).…”

Species identification of Australian marsupials using collagen fingerprinting

“…For example, while eastern and western grey kangaroos (M. giganteus and M. fuliginosus, respectively) share an identical set of ZooMS peptide markers, the eastern species is today found in the eastern states of Australia, while the western species occurs in the southern and western parts of Australia [84]. However, the potential for recent local extinctions as well as range shifts should not be overlooked [19,[85][86][87]. Eastern and western kangaroo ranges overlap in south-central Australia, and a recent aDNA study has demonstrated that, historically, both species were found on Kangaroo Island, whereas it was previously thought that only the western variety had roamed there [88].…”

“…Archaeologists, palaeontologists and other researchers have uncovered an assortment of faunal remains in Australia, dating from the late Pleistocene to the historical period [12][13][14][15][16][17][18][19]. However, the continent's often harsh environmental conditions [20][21][22], together with other factors like scavenging by marsupial carnivores [23][24][25], frequently result in a large number of highly fragmented, morphologically unidentifiable bone fragments in archaeological and palaeontological assemblages.…”

Intra-skeletal vascular density in a bipedal hopping macropod with implications for analyses of rib histology

“…A skeleton of an eastern grey kangaroo (M. giganteus) was recovered as a subfossil surface find in the Manning Karst Region of eastern New South Wales during part of a paleontological investigation (Price et al 2019). No animal was sacrificed or harmed in this study, and permissions to excavate were obtained from the landowner.…”