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Around 88 large vertebrate taxa disappeared from Sahul sometime during the Pleistocene, with the majority of losses (54 taxa) clearly taking place within the last 400,000 years. The largest was the 2.8-ton browsing Diprotodon optatum, whereas the ∼100- to 130-kg marsupial lion, Thylacoleo carnifex, the world's most specialized mammalian carnivore, and Varanus priscus, the largest lizard known, were formidable predators. Explanations for these extinctions have centered on climatic change or human activities. Here, we review the evidence and arguments for both. Human involvement in the disappearance of some species remains possible but unproven. Mounting evidence points to the loss of most species before the peopling of Sahul (circa 50-45 ka) and a significant role for climate change in the disappearance of the continent's megafauna.

Aim: Within the intensively‐studied, well‐documented latitudinal diversity gradient, the deep‐sea biodiversity of the present‐day Norwegian Sea stands out with its notably low diversity, constituting a steep latitudinal diversity gradient in the North Atlantic. The reason behind this has long been a topic of debate and speculation. Most prominently, it is explained by the deep‐sea glacial disturbance hypothesis, which states that harsh environmental glacial conditions negatively impacted Norwegian Sea diversities, which have not yet fully recovered. Our aim is to empirically test this hypothesis. Specific research questions are: (1) Has deep‐sea biodiversity been lower during glacials than during interglacials? (2) Was there any faunal shift at the Mid‐Brunhes Event (MBE) when the mode of glacial–interglacial climatic change was altered? Location: Norwegian Sea, deep sea (1819–2800 m), coring sites MD992277, PS1243, and M23352. Time period: 620.7–1.4 ka (Middle Pleistocene–Late Holocene). Taxa studied: Ostracoda (Crustacea). Methods: We empirically test the deep‐sea glacial disturbance hypothesis by investigating whether diversity in glacial periods is consistently lower than diversity in interglacial periods. Additionally, we apply comparative analyses to determine a potential faunal shift at the MBE, a Pleistocene event describing a fundamental shift in global climate. Results: The deep Norwegian Sea diversity was not lower during glacial periods compared to interglacial periods. Holocene diversity was exceedingly lower than that of the last glacial period. Faunal composition changed substantially between pre‐ and post‐MBE. Main conclusions: These results reject the glacial disturbance hypothesis, since the low glacial diversity is the important precondition here. The present‐day‐style deep Norwegian Sea ecosystem was established by the MBE, more specifically by MBE‐induced changes in global climate, which has led to more dynamic post‐MBE conditions. In a broader context, this implies that the MBE has played an important role in the establishment of the modern polar deep‐sea ecosystem and biodiversity in general. [ABSTRACT FROM AUTHOR]

We describe new Late Miocene mammalian specimens from the Maimará Formation (Late Miocene to Early Pliocene) exposed at Humahuaca Basin (23°–24°S), northwestern Argentina (NWA), and analyse their taxonomy and relevance for our understanding of the initial stages of the Great American Biotic Interchange (GABI). The stratigraphical and geochronological control of the studied specimens indicates a time window of c. 6.6–5.8 Ma. These data are crucial for establishing the oldest records of the Holarctic immigrants of the GABI. The first record of cricetid rodents from the Maimará Formation is reported. Moreover, with an age of c. 6 Ma it is the first appearance datum (FAD) of these rodents in South America. The age of the procyonid Cyonasua recorded in this unit is estimated between c. 6.6 and c. 6.4 Ma. The record of procyonids and cricetids in the same continuous sedimentary sequence suggests that the time interval between the dispersion of both groups into the continent during GABI was c. 1 myr. Of the autochthonous mammals from the Maimará Formation, the first records of litopterns, chlamyphorid and mylodontine xenarthrans, and caviomorph rodents (including new species Pithanotomys? solisae and Palaeocavia humahuaquense) are described. FADs of immigrant and autochthonous mammals in NWA suggest a major faunal turnover during GABI at the Messinian, probably linked to global climatic changes and the tectonic activity that affected the Humahuaca Basin at that time. Hypsodonty, a dominant feature among Maimaran mammals, may be related to a landscape strongly influenced by the Andean uplift. [ABSTRACT FROM AUTHOR]

The Suidae from the late Miocene of Alsótelekes (northeastern Hungary, Borsod-Abaúj-Zemplén county) are described and assigned to Propotamochoerus palaeochoerus (Suinae) and cf. Parachleuastochoerus (Tetraconodontinae). The co-occurrence of these two taxa agrees with a reference to the early Vallesian (MN 9), as previously indicated from biochronological correlation of the small mammal fauna, and suggests the presence of woodland environments, with abundance of below-ground resources and direct access to water. This fits well with the diverse wetlands and riparian forests that characterized Lake Pannon ∼10 Ma, as documented in the geographically close site of Rudabánya. The convoluted taxonomy of European Tetraconodontinae is discussed. [ABSTRACT FROM AUTHOR]

An extraordinary sequence of fossiliferous levels at the locality of Gran Dolina in the Atapuerca Hills (Burgos, Spain) records the Early–Middle Pleistocene transition. These levels are well dated by a variety of methods, including palaeomagnetism, which locates Lower–Middle Pleistocene boundary at the top of level TD7. Level TD6 is the type site of the species Homo antecessor and yielded over 90% of the European Early Pleistocene human record, while other levels have an archaeological record. The present paper deals with the earliest Middle Pleistocene ungulates of TD8, but we plan to describe the faunas, or at least the ungulates, of levels TD4 to TD8 in the context of the faunal changes that took place around the Early–Middle Pleistocene transition. About 600 fossils could be assigned to a taxon and on this basis the following ungulates are described from TD8: horse Equus altidens , rhinoceros Stephanorhinus aff. etruscus , wild boar Sus scrofa , hippopotamus Hippopotamus sp., red deer Cervus elaphus , giant deer Eucladoceros aff. giulii , giant deer Megaceroides solilhacus , fallow deer Dama vallonnetensis , and bison Bison voigtstedtensis . The evolution of these taxa is discussed. The fauna from level TD8 dates to the earliest Middle Pleistocene (stage 19) and differs from later faunas in the retention of a small rhinoceros ( Stephanorhinus aff. etruscus ) and the latest representative of the genus Eucladoceros . It differs from earlier faunas in having the striped hyaena. Together with the fauna from TD7, in which the Brunhes–Matuyama boundary is recorded, TD8 will provide the most precise criterions for correlation of the Early–Middle Pleistocene boundary on the basis of fossils of large mammals. Profound changes in the global climate system started to take place during the late Early Pleistocene, leading to intensive environmental and faunal change and to human dispersal into Europe. These events mark the beginning of a new time and the Early–Middle Pleistocene boundary is taken somewhere in the middle of this drawn out process. It is taken at a palaeomagnetic change, which is convenient, but this does not appear to be close to an important climatic or faunal change. Ten faunal events are recognized in the period from about 1.2 to 0.5 Ma. The event closest to the Early–Middle Pleistocene boundary is one of the minor events and up to now it is recorded in only few localities, principally in TD8. [ABSTRACT FROM AUTHOR]

We present an updated taxonomy and faunal distribution of the micromammal fossil record from the Aragonian and Lower Vallesian of the Calatayud-Montalbán Basin. The analysed record includes the orders Rodentia, Eulipotyphla, and Lagomorpha. The pattern of species turnover shows seven major faunal events, which are correlated with major climate changes based on marine stable oxygen and carbon isotope records. Episodes δ 18 O Mi-2 and Mi-3 are significantly correlated with major micromammal turnover at the boundaries between the Lower and Middle Aragonian and the Middle and Upper Aragonian, respectively. Our results support the existence of a selective turnover during the Aragonian and Lower Vallesian. [ABSTRACT FROM AUTHOR]

The basal portion of the Permian Rio do Rasto Formation (Serrinha Member), Passa Dois Group, Paraná Basin, Brazil, records an entirely new bivalve fauna intercalated between the underlying Pinzonella neotropica assemblage (uppermost portion of the Teresina Formation) and the overlying Leinzia similis assemblage (Rio do Rasto Formation). Mollusks of these assemblages lived in marginal shallow-water habitats of an immense epeiric sea and were dominated by endemic bivalve species. Taxonomic analysis revealed the presence of Terraia curvata (60.61%), Astartellopsis prosoclina (19.70%), Cowperesia emerita (10.61%), Leinzia curta (4.55%), Terraia bipleura (3.03%) and Beurlenella elongatella (1.52%), which are associated with conchostracans and plant remains. Species composition, abundance, and dominance in this novel assemblage differ notably from the preceding ones, suggesting a substantial evolutionary turnover. Regional-scale environmental changes recognized based on taphonomy, facies analysis, and geochemical data consist of progressive freshening of the marginal habitats of the Paraná Basin and taxic changes that include the following: (a) loss of genera, (b) decrease in bivalve abundance and ecological guilds, (c) disappearance of the dominant bivalve group (Pinzonellinae) and (d) diversification of Terrainae bivalves. The ecological signature also changed notably because only infaunal suspension-feeding bivalves are present, indicating a significant loss of functional diversity at the regional scale. Likely stressor factors (among others) are tied to freshening events, suggesting profound changes in (a) salinity, (b) primary productivity and (c) a lack of coarse, stable substrates coupled with high bioturbation rates. Hence, our regional example could offer valuable clues to benthic (bivalve) community responses in a habitat subjected to (a) rapid climate changes and (b) freshening events in shallow-water settings. Finally, the stratigraphic range of the dominant species ( T. curvata ) appears to be restricted to the basal portion of the Rio do Rasto Formation. Based on the presence of this species and of C. emerita , the novel assemblage is tentatively correlated with that of the Permian Gai-As Formation in the Huab region of Namibia, thus supporting previous assumptions of a seaway connecting both basins during the Guadalupian Epoch. [ABSTRACT FROM AUTHOR]

Around 88 large vertebrate taxa disappeared from Sahul sometime during the Pleistocene, with the majority of losses (54 taxa) clearly taking place within the last 400,000 years. The largest was the 2.8-ton browsing Diprotodon optatum, whereas the ~100- to 130-kg marsupial lion, Thylacoleo carnifex, the world's most specialized mammalian carnivore, and Varanus priscus, the largest lizard known, were formidable predators. Explanations for these extinctions have centered on climatic change or human activities. Here, we review the evidence and arguments for both. Human involvement in the disappearance of some species remains possible but unproven. Mounting evidence points to the loss of most species before the peopling of Sahul (circa 50–45 ka) and a significant role for climate change in the disappearance of the continent's megafauna. [ABSTRACT FROM AUTHOR]

Abstract: Continuous Eocene through Oligocene sedimentary sedimentary sections were obtained at Holes 1218A, 1219A, and 1220A drilled during Leg 199 of the Ocean Drilling Program in the central equatorial Pacific. Quantitative analysis of radiolarian assemblages between the upper Eocene through lower Oligocene sedimentary successions revealed that major faunal changes of radiolarians occurred in the late Eocene (35.5–35.7 Ma; Subchron C16n1), around the Eocene/Oligocene boundary (33.7–33.8 Ma; upper Subchron C13r) and in the early Oligocene (30.9–31.3 Ma; uppermost Subchron C12r). The faunal change in the late Eocene is characterized by a stepwise decrease of tropical Eocene species and an increase in cosmopolitan, probably cool-water-tolerant, radiolarians; however, without a significant change in species diversity and radiolarian accumulation rates. The stratigraphic level of this late Eocene turnover came after the late Eocene impact event, and may have been more related to global cooling and associated oceanographic changes than to asteroid impact. The turnover around the Eocene/Oligocene boundary, corresponding to the Oi-1 event, is the most critical during the Eocene–Oligocene transition. Many biotic events such as a sudden drop of species diversity, an increase in the cosmopolitan radiolarian group, a large number of species turnovers, and a drop in radiolarian accumulation rates occurred at or just above this level. Together these indicators suggest a major restructuring of radiolarian assemblages from the high diversity Eocene fauna to a low diversity Oligocene one. The third turnover event within early Oligocene is represented by a replacement of dominant species with a sudden decrease in radiolarian accumulation rates. However, this Oligocene turnover is not consistent with other major δ 18O isotope events, such as Oi-1b and Oi-2. [Copyright &y& Elsevier]