The microstratigraphy and depositional environments of Lida Ajer and Ngalau Gupin, two fossil-bearing tropical limestone caves of west Sumatra.

Lida Ajer and Ngalau Gupin are karstic caves situated in the Padang Highlands, western Sumatra, Indonesia. Lida Ajer is best known for yielding fossil evidence that places the arrival of Homo sapiens in Southeast Asia during Marine Isotope Stage 4, one of the earliest records for the region. Ngalau Gupin recently produced the first record of hippopotamid Hexaprotodon on the island, representing the only globally extinct taxon in Pleistocene deposits from Sumatra.

Expanded geographic distribution and dietary strategies of the earliest Oldowan hominins and .

The oldest Oldowan tool sites, from around 2.6 million years ago, have previously been confined to Ethiopia's Afar Triangle. We describe sites at Nyayanga, Kenya, dated to 3.

Speleological and environmental history of Lida Ajer cave, western Sumatra.

Some of the earliest evidence for the presence of modern humans in rainforests has come from the fossil deposits of Lida Ajer in Sumatra. Two human teeth from this cave were estimated to be 73-63 thousand years old, which is significantly older than some estimates of modern human migration out of Africa based on genetic data. The deposits were interpreted as being associated with a rainforest environment based largely on the presence of abundant orangutan fossils.

Global long-term stability of individual dietary specialization in herbivorous mammals.

Dietary variation within species has important ecological and evolutionary implications. While theoreticians have debated the consequences of trait variance (including dietary specialization), empirical studies have yet to examine intraspecific dietary variability across the globe and through time. Here, we use new and published serial sampled δC values of herbivorous mammals from the Miocene to the present (318 individuals summarized, 4134 samples) to examine how dietary strategy (i.

Species identification of Australian marsupials using collagen fingerprinting.

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.

High-resolution high-throughput thermal neutron tomographic imaging of fossiliferous cave breccias from Sumatra.

We employ high-throughput thermal-neutron tomographic imaging to visualise internal diagnostic features of dense fossiliferous breccia from three Pleistocene cave localities in Sumatra, Indonesia. We demonstrate that these seemingly homogeneous breccias are an excellent source of data to aid in determining taphonomic and depositional histories of complex depositional sites such as tropical caves. X-ray Computed Tomographic (CT) imaging is gaining importance amongst palaeontologists as a non-destructive approach to studying fossil remains.

Multiple hominin dispersals into Southwest Asia over the past 400,000 years.

Pleistocene hominin dispersals out of, and back into, Africa necessarily involved traversing the diverse and often challenging environments of Southwest Asia. Archaeological and palaeontological records from the Levantine woodland zone document major biological and cultural shifts, such as alternating occupations by Homo sapiens and Neanderthals. However, Late Quaternary cultural, biological and environmental records from the vast arid zone that constitutes most of Southwest Asia remain scarce, limiting regional-scale insights into changes in hominin demography and behaviour.

No evidence for widespread island extinctions after Pleistocene hominin arrival.

The arrival of modern humans into previously unoccupied island ecosystems is closely linked to widespread extinction, and a key reason cited for Pleistocene megafauna extinction is anthropogenic overhunting. A common assumption based on late Holocene records is that humans always negatively impact insular biotas, which requires an extrapolation of recent human behavior and technology into the archaeological past. Hominins have been on islands since at least the early Pleistocene and for at least 50 thousand y (ka).

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

Human ribs are thought to be less affected by mechanical strain at the microscopic level than limb bones, implying that rib remodelling better reflects bone physiological homeostasis. Here, we test the hypothesis that rib tissue will be well vascularized and thus enhance susceptibility to metabolic influence. An intra-skeletal comparison of bone vascular canal density was conducted using a macropod animal model adapted to bipedal habitual hopping.

Environmental drivers of megafauna and hominin extinction in Southeast Asia.

Southeast Asia has emerged as an important region for understanding hominin and mammalian migrations and extinctions. High-profile discoveries have shown that Southeast Asia has been home to at least five members of the genus Homo. Considerable turnover in Pleistocene megafauna has previously been linked with these hominins or with climate change, although the region is often left out of discussions of megafauna extinctions.

Human footprints provide snapshot of last interglacial ecology in the Arabian interior.

The nature of human dispersals out of Africa has remained elusive because of the poor resolution of paleoecological data in direct association with remains of the earliest non-African people. Here, we report hominin and non-hominin mammalian tracks from an ancient lake deposit in the Arabian Peninsula, dated within the last interglacial. The findings, it is argued, likely represent the oldest securely dated evidence for in Arabia.

A new family of diprotodontian marsupials from the latest Oligocene of Australia and the evolution of wombats, koalas, and their relatives (Vombatiformes).

We describe the partial cranium and skeleton of a new diprotodontian marsupial from the late Oligocene (~26-25 Ma) Namba Formation of South Australia. This is one of the oldest Australian marsupial fossils known from an associated skeleton and it reveals previously unsuspected morphological diversity within Vombatiformes, the clade that includes wombats (Vombatidae), koalas (Phascolarctidae) and several extinct families. Several aspects of the skull and teeth of the new taxon, which we refer to a new family, are intermediate between members of the fossil family Wynyardiidae and wombats.

Extinction of eastern Sahul megafauna coincides with sustained environmental deterioration.

Explanations for the Upper Pleistocene extinction of megafauna from Sahul (Australia and New Guinea) remain unresolved. Extinction hypotheses have advanced climate or human-driven scenarios, in spite of over three quarters of Sahul lacking reliable biogeographic or chronologic data. Here we present new megafauna from north-eastern Australia that suffered extinction sometime after 40,100 (±1700) years ago.

Isotopic evidence for initial coastal colonization and subsequent diversification in the human occupation of Wallacea.

The resource-poor, isolated islands of Wallacea have been considered a major adaptive obstacle for hominins expanding into Australasia. Archaeological evidence has hinted that coastal adaptations in Homo sapiens enabled rapid island dispersal and settlement; however, there has been no means to directly test this proposition. Here, we apply stable carbon and oxygen isotope analysis to human and faunal tooth enamel from six Late Pleistocene to Holocene archaeological sites across Wallacea.

Micro Methods for Megafauna: Novel Approaches to Late Quaternary Extinctions and Their Contributions to Faunal Conservation in the Anthropocene.

Drivers of Late Quaternary megafaunal extinctions are relevant to modern conservation policy in a world of growing human population density, climate change, and faunal decline. Traditional debates tend toward global solutions, blaming either dramatic climate change or dispersals of Homo sapiens to new regions. Inherent limitations to archaeological and paleontological data sets often require reliance on scant, poorly resolved lines of evidence.

Hidden in plain sight: reassessment of the pig-footed bandicoot, Chaeropus ecaudatus (Peramelemorphia, Chaeropodidae), with a description of a new species from central australia, and use of the fossil record to trace its past distribution.

The Pig-footed Bandicoot, Chaeropus ecaudatus, an extinct arid-adapted bandicoot, was named in 1838 based on a specimen without a tail from the Murray River in New South Wales. Two additional species were later named, C. castanotis and C.

Somewhere beyond the sea: Human cranial remains from the Lesser Sunda Islands (Alor Island, Indonesia) provide insights on Late Pleistocene peopling of Island Southeast Asia.

The migration of anatomically modern humans (AMH) from Africa to every inhabitable continent included their dispersal through Island Southeast Asia (ISEA) to Australia. Significantly, this involved overwater dispersal through the Lesser Sunda Islands between Sunda (continental Southeast Asia) and Sahul (Australia and New Guinea). However, the timing and direction of this movement is still debated.

Microanatomical Record of Cortical Bone Remodeling and High Vascularity in a Fossil Giant Rat Midshaft Femur.

Rat cortical bone does not typically undergo secondary (Haversian) remodeling. Haversian organization of rat bone has been mainly observed in experimental settings following biomechanical or dietary manipulation. Here, we report an observation of cortical secondary osteons within a histological femur cross-section from an extinct (late Quaternary) form of Timorese giant rat (Murinae gen.

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

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.

Least-cost pathway models indicate northern human dispersal from Sunda to Sahul.

Archaeological records from Australia provide the earliest, indirect evidence for maritime crossings by early modern humans, as the islands to the north-west of the continent (Wallacea) have never been connected to the mainland. Suggested in 1977 by Joseph B. Birdsell, the two main routes from Sunda (mainland Southeast Asia) to Sahul (Australia-New Guinea), still in debate today, are a northern route through Sulawesi with a landing in New Guinea, or a southern route through Bali, Timor and thence landing in northern Australia.

Fossil herbivore stable isotopes reveal middle Pleistocene hominin palaeoenvironment in 'Green Arabia'.

Despite its largely hyper-arid and inhospitable climate today, the Arabian Peninsula is emerging as an important area for investigating Pleistocene hominin dispersals. Recently, a member of our own species was found in northern Arabia dating to ca. 90 ka, while stone tools and fossil finds have hinted at an earlier, middle Pleistocene, hominin presence.

Orangutans venture out of the rainforest and into the Anthropocene.

Conservation benefits from understanding how adaptability and threat interact to determine a taxon's vulnerability. Recognizing how interactions with humans have shaped taxa such as the critically endangered orangutan ( spp.) offers insights into this relationship.