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We use synchrotron x-ray tomography of annual growth increments in the dental cementum of mammaliaforms (stem and crown fossil mammals) from three faunas across the Jurassic to map the origin of patterns of mammalian growth patterns, which are intrinsically related to mammalian endothermy. Although all fossils studied exhibited slower growth rates, longer life spans, and delayed sexual maturity relative to comparably sized extant mammals, the earliest crown mammals developed significantly faster growth rates in early life that reduced at sexual maturity, compared to stem mammaliaforms. Estimation of basal metabolic rates (BMRs) suggests that some fossil crown mammals had BMRs approaching the lowest rates of extant mammals. We suggest that mammalian growth patterns first evolved during their mid-Jurassic adaptive radiation, although growth remained slower than in extant mammals. [ABSTRACT FROM AUTHOR]

The Guadix-Baza Basin (southern Spain) displays one of the best continental records from the Late Miocene to the Middle Pleistocene in western Europe, with many localities of fossil small mammals in a quite complete and continuous stratigraphic sequence. The Late Miocene continentalization of the Guadix-Baza Basin was firstly mentioned in the 1980s based on the presumed presence of Hipparion gromovae granatensis at the site of Abla (Almería province). Subsequent discoveries of late Turolian deposits confirmed the Late Miocene continentalization of the basin. The interest in the Abla site led to a second sampling campaign to look for microvertebrate fossils, which proved successful. In this paper, a complete taxonomic study of the novel microvertebrate fauna from Abla is presented, providing updated information on the age of the locality. Representatives of the vertebrate families Cyprinidae, Alytidae, Anguidae, Soricidae, Cricetidae, and Muridae have been identified. The presence of Stephanomys specimens exceeding the size of latest Miocene-earliest Pliocene species allows us to correlate the Abla site with the Early Pliocene (Ruscinian), a younger age than initially stated. A qualitative paleoecological interpretation based on the herpetofauna suggests the dominance of open environments with presence of permanent water bodies during the deposition of the Abla site, under warmer and more humid climate conditions than today in the Guadix-Baza Basin. A revision of the Hipparion remains from this locality showed that the sample is closer to Hipparion fissurae than to the initially assigned species. [ABSTRACT FROM AUTHOR]

The Neogene-Quaternary continental deposits cover large areas of Greece and several fossil mammal sites have been discovered in the country. There are several collections of large fossil mammals for this time span, which provide important data for the fauna biochronology, correlations, palaeoecology and palaeogeography of the area. The last lists with the fauna, age and biochronology of the Greek large mammal localities were given in 2006 for the Neogene and in 2001 for the Quaternary. Extensive research over the last twenty years provided several new localities, and many data and information were published. Therefore, an updating of the lists was more than necessary, and the present article deals with it; it covers the time span untill June 2023. Lists include all faunal information as the systematic classification, chronology, biostratigraphic correlation of the faunas, and main bibliography. It is worth mentioning that some of the Greek localities are key-localities for the Eastern Mediterranean region, e.g., Pikermi, Axios Valley, Villafranchian collection. These faunas are important for the comparison and identification of new collections, correlations, palaeoecology, and palaeogeography of Neogene European mammals. [ABSTRACT FROM AUTHOR]

Bianfudong (pinyin for Bat Cave) is a paleolithic site that was recently discovered in Heqing, Yunnan in southwestern China. Several hominin fossils, stone artifacts and more than 69,000 mammal fossils were unearthed in 2019. The hominin fossils and stone artifacts were excavated from the upper part (layers 1–12) of the section with an age range of 180–70 ka BP. Some large mammal fossils and micromammalian remains were collected from the lower part of the section (layers 22–30), which has an age >180 ka BP. This paper describes the micromammalian fossils collected from layers 25–30 and analyzes the fauna composition and paleohabitats. A total of 638 micromammal specimens represent 12 species, including 11 extant species i.e. Euroscaptor longirostris , Blarinella wardi , Anourosorex squamipes , Crocidura vorax , Eothenomys (Anteliomys) chinensis , E. (A.) proditor , Apodemus chevrieri , Ap. draco , Ap. latronum , Micromys minutus , and Niviventer confucianus , and one extinct species Anourosorex qianensis. The two arvicolid Eothenomys species dominate, both in the number of identified specimens and the minimum number of individuals. The composition of the Bianfudong micromammalian fauna can be compared with the faunas of Sanjiacun in Chenggong of Yunnan Province, Mawokoudong in Bijie and Xinglongdong in Fengjie, Guizhou Province. Using the random forest model with modern meteorological data, we calculated the mean annual precipitation (MAP) and the mean annual temperature (MAT) for all 11 living species in the Bianfudong. The MAP was inferred as 1008.04 mm, close to modern data in the Heqing area, while the MAT was slightly lower at 12.84 °C. The dominance of Eothenomys also supports a slightly cooler climate during the late Middle Pleistocene in the Heqing area. [ABSTRACT FROM AUTHOR]

Tectonic processes drive the evolution of basins through local and regional changes in topographic relief, which have long-term effects on mammalian richness and distribution. Mammals respond to the resulting changes in landscape and climate through evolution, shifts in geographic range, and by altering their community composition. Here, we evaluate the relationship between tectonic episodes and the diversification history of fossil mammals in the Miocene Dove Spring Formation (12.5-8.5 Ma) of southern California, USA. This formation contains a rich fossil record of mammals and other vertebrates as well as structural and sedimentological evidence for tectonic episodes of basin extension, rotation, and translation. We used several methods to compare the fossil record to the tectonic history of the Dove Spring Formation. We updated the formation's geochronology to incorporate current radiometric dating standards and measured additional stratigraphic sections to refine the temporal resolution of large mammal (>1 kg) fossil localities to 200-kyr (or shorter) intervals. Observed species richness over time follows the same trend as the number of localities and specimens, suggesting that richness reflects sampling intensity. Estimates of stratigraphic ranges with 80% confidence intervals were used to conduct per capita diversification analysis and a likelihood approach to changes in faunal composition from one time interval to the next. While edge effects influence time bins at the beginning and end of the study interval, we found changes in diversification rates and faunal composition that are not solely linked to preservation. Several rare species appear at 10.5 Ma and persist through the top of the formation despite variable preservation rates. Changes in faunal composition at 12.1 Ma and 10.5 Ma are not associated with elevated preservation rates, which indicates that some faunal changes are not primarily driven by sampling effort. The lower portion of the formation is characterized by high origination rates and long residence times. The upper portion has high per capita extinction rates that increased in magnitude as basin rotation and translation progressed from 10.5 Ma. The greatest change in faunal composition coincided with basin rotation and translation that interrupted a long-running extensional period. Tectonics played key roles in the diversity of mammals by determining fossil productivity and shaping the landscapes that they inhabited. [ABSTRACT FROM AUTHOR]

Linking the species interactions occurring at the scale of local communities to their potential impact at evolutionary timescales is challenging. Here, we used the high‐resolution fossil record of mammals from the Iberian Peninsula to reconstruct a timeseries of trophic networks spanning more than 20 million years and asked whether predator–prey interactions affected regional extinction patterns. We found that, despite small changes in species richness, trophic networks showed long‐term trends, gradually losing interactions and becoming sparser towards the present. This restructuring of the ecological networks was driven by the loss of medium‐sized herbivores, which reduced prey availability for predators. The decrease in prey availability was associated with predator longevity, such that predators with less available prey had greater extinction risk. These results not only reveal long‐term trends in network structure but suggest that prey species richness in ecological communities may shape large scale patterns of extinction and persistence among predators. [ABSTRACT FROM AUTHOR]

The studies of the small mammal fossil and recent assemblages from the Limay river basin (Northwestern Patagonia) have strongly increased during the last decade. Taxonomic, taphonomic, and paleoecological information about small rodents and marsupials recovered from fossil sites offers the opportunity to discuss the periods of change and stability in the conformation of their communities through the Anthropocene. Here, we used two large data matrix of fossil and recent small mammal samples. As starting point, we considered the small mammal record of Epullán Grande cave (LL thereafter), which covers the Early Holocene/Post-hispanic Period, in order to assess the impact of anthropic activities on the small mammal communities during the Anthropocene. The taphonomic analysis performed on the newest samples from LL confirms the predatory activity of Tyto furcata on sigmodontines and human consumption on caviomorphs (mostly for the last ca. 1000 years). The analysis of manganese oxide staining suggested higher levels of moisture during the earliest formation of the LL sequence. The taxonomic results indicate a major diversity in the small mammal fossil assemblages to the later periods of LL and other fossil sequences of the Limay basin of the Anthropocene. Conversely, opportunistic sigmodontines (Abrothrix olivacea, Calomys musculinus, Eligmodontia spp. and Oligoryzomys longicaudatus) experienced a growth in the recent samples. Some stenoic and specialist species (Euneomys spp., Lestodelphys halli, Loxodontomys micropus and Reithrodon auritus) were abundant in the temporal units associated with the Anthropocene, but now are in retraction. Additionally, the drop in the diversity of recent assemblages supports a restructuration of small mammal communities from Limay river basin occurred in the 20th century. [ABSTRACT FROM AUTHOR]

The remarkable uplift of the Tibetan Plateau in the Neogene had great impacts on the climate and environment of East Asia and even the world. Therefore, establishment of the Neogene stratigraphic framework of the Tibetan Plateau is of great significance to research in various fields of geosciences. Based on marine sediments, the international chronostratigraphic system of the Neogene is divided into six stages in the Miocene and two stages in the Pliocene. Since the beginning of the Cenozoic, the share of terrestrial strata on continents has increased rapidly. By the Neogene, it had far exceeded that of marine strata, and almost all deposits on the Tibetan Plateau and its surrounding areas were terrestrial strata. In China, the Miocene includes five stages and the Pliocene includes two stages. Except for the Tunggurian of the Miocene, which has a lower boundary at 15 Ma, the other stages have the same paleomagnetic definitions and time intervals as the corresponding international marine stages. Mammalian fossils play a very important role in the division and correlation of Cenozoic terrestrial strata, and rodent, carnivore, proboscidean, perissodactyl and artiodactyl fossils are especially important in Neogene terrestrial biostratigraphy. There are many basins with well-exposed strata and abundant mammalian fossils in the Tibetan Plateau. The lower boundary stratotype sections of the Neogene Xiejian and Bahean stages are located respectively in the Xining and Linxia basins, and there are precise paleomagnetic dates in coordination with mammalian fossils. The lower boundary stratotypes of other stages can also be effectively determined in the Tibetan Plateau. Many first appearing mammalian genera in East Asia also appeared in the Tibetan Plateau and its surrounding areas, especially in the Linxia Basin on the northeast margin and in the Siwaliks on the southwest margin. Among them, Prodeinotherium first appeared at the bottom of the Miocene in the Siwaliks, and the earliest Hipparion of the Old World first appeared at the bottom of the Bahean Stage in the Linxia Basin. Carbon and oxygen isotope analysis of enamel and paleosols of Cenozoic sediments and mammal fossils in the Tibetan Plateau and its surrounding areas have been used to reconstruct the climate, environment and vegetation development characteristics, and revealed that these changes were not only related to global change, but also had regional features. Evidence of the Late Miocene C4 plant expansion event based on carbon isotope changes comes from the southern margin of the Tibetan Plateau, but in sharp contrast, δ13C indicates that there was still no clear or significant C4 plant signal on the northern margin of the Tibetan Plateau until the end of the Neogene. The δ18O analysis shows that there were several major climate change events in the Cenozoic, especially in the Late Miocene at about 7 Ma, when positive drift of δ18O indicates that the northern and southern sides of the Tibetan Plateau were changing to drier environments. The strong uplift of the Tibetan Plateau in the Late Miocene strengthened the thermal contrast between sea and land, which strengthened monsoon circulation and led to the expansion of C4 vegetation in South Asia. However, the East Asian summer monsoon, which can bring atmospheric precipitation and a climate suitable for C4 plants to northern China, was not enough to affect the northern Tibetan Plateau. The Tibetan Plateau on the whole rose to an altitude of about 3000 m in the Miocene, becoming a barrier to mammalian migration; it reached its modern altitude of more than 4000 m in the Pliocene, thus forming a cryosphere environment, which led to the emergence of ancestral types of the Ice Age fauna. [ABSTRACT FROM AUTHOR]

Body mass is a pivotal quantity in palaeobiology but must be inferred from an imperfect fossil record. We analyse the performance of regression models derived from various dentoskeletal predictors in mammals to inform fossils from the early, Mesozoic history of this radiation. Our focus is on the critical small end of the size spectrum; critical because the earliest mammals were small, because small size persisted onto the stems of the major extant radiations, and because small mammals compose a large proportion of crown diversity. The sampling strategy is diverse in terms of both phylogeny and skeletal predictors: the former allows a general application, while the latter enables comparison of various models. Linear regressions based on extant small mammals indicate a universal correlation of body mass with observed measurements, but with clear differences in precision. Postcranial predictors outperform jaw and dental metrics, with certain femoral joint dimensions providing surprisingly precise predictions. Our results indicate complex patterns of size evolution within the small-bodied category, including the possibility that multiple Mesozoic species approached the theoretical lower limit of mammalian body size. The ability to study such dynamics only becomes possible when predicting body mass within a strict, highly focused phylogenetic context. The heuristic value of the models we provide here is not limited to the Mesozoic but is applicable to small-bodied mammals of any geologic age. [ABSTRACT FROM AUTHOR]

Geological relics are one of the important components of geoscience culture, so studies on their distribution characteristics and genesis are helpful to the effective investigation and evaluation of the landscape resources in geological relics. Zhaotong City is located on the southeastern margin of the Tibetan Plateau in the northeastern Yunnan Province of Southwest China. It belongs to the Yangtze plate of South China, which is located at the southwest edge of the Yangtze block-a secondary tectonic unit within the plate. The formation and distribution of landscapes of geological relics in Zhaoyang district are closely related to the formation and evolution of the Zhaotong intermountain basin. On the basis of detailed field investigations of geological relics, this study comprehensively classifies and analyzes the genesis of various geological relics in Zhaoyang district of Zhaotong City in northeastern Yunnan Province. The strata in the Zhaoyang area are fully exposed, ranging from the Cambrian Meishucun Formation (Zhongyicun member of Dengying Formation) to the Quaternary system (Neogene). The Cambrian and Ordovician systems are mainly exposed in Yanshan township and Dazhaizi township by the Jinsha river, and are mainly buried deep underground in other areas. The Meishucun Formation at the bottom of the Cambrian is a phosphate-bearing rock series, with the upper Qiongzhusi Formation and Canglangpu Formation being a combination of terrigenous sandstone and mudstone. The Longwangmiao Formation to the Erdaoshui Formation and the Ordovician Formation at the top of the lower Cambrian are mostly composed of carbonate rocks. Meishucun Formation at the bottom of the Cambrian is composed of the phosphorus-bearing rock series. The upper Qiongzhusi Formation and Canglangpu Formation are the combination of terrigenous sand and mudstone. The top of the lower Cambrian Longwangmiao Formation to the Erdaoshui Formation and the Ordovician are mostly composed of carbonate rocks. The combination of terrigenous sand and mudstone, accompanied by muddy limestone, is developed in Hong'anpo Formation of the Silurian system to the upper part of middle Devonian. Thick carbonate deposits are developed in Qujing Formation at the top of middle Devonian to the Maokou Formation of the lower Permian. From the Xuanwei Formation at the top of Permian to the Cretaceous, there are only sporadic outcrops-mainly terrigenous sand and mudstone-in Zhaoyang district. The Paleogene mainly consists of sand, mudstone and thick lignite. The bottom of the Neogene is mainly composed of conglomerate with a small amount of limestone and sandstone; the clay soil is interbedded with gravel in the middle part; the grey clay soil is interbedded with siltstone at the bottom. The Quaternary system is filled with swampy sediments of clays, silts, etc. and abundant biological fossils, such as ostracods, stonewort, ichthyodont and viviparus. The results show that the geological relics of Zhaoyang district can be divided into western region and eastern region. The western region is a basalt platform like Dashanbao, including volcanic landform, plateau lakes and wetland. The eastern region takes carbonate rock karst landform of Zhaotong mountain basin as the center by paleontological fossil landscape. The abundant lithology, like carbonate rock, shale, sandstone, basalt and so on, contributes to karst development and karst geomorphology difference. The tectonic landforms formed by different degrees of fault-fold are the main factors of the differentiation of geological relics. Under background of stratigraphic lithology and tectonic geomorphology, hydrologic conditions provide external dynamic factors for abundant geological landscapes. Our research is of great scientific value of geological relics resources in Zhaotong, and also provides a basis for studies on mammal fossils in Late Neogene. It is concluded as follows, (1) Geological relics of Zhaoyang district in Zhaotong City include canyon landform, volcanic landform, karst landform, plateau lake, wetland and fossil landscape, etc., with great value of tourism. (2) Abundant stratigraphic lithology is the basis for the development of different geological relics. Two sets of outcrops of carbonate rocks widely shaped the modern geological landscape with karst landform and water landform in the study area. Vertically, the strata of Zhaoyang district are characterized by an interphase pattern of three sets of water-resisting rock series and two sets of water-bearing rock series, being the geological foundation of geological relics. From the bottom to the top of strata are distributed the water-resisting rock series mainly composed of mudstone from the Cambrian Qiongzhusi Formation to the Canglangpu Formation, the water-bearing rock series composed of carbonate rock and diamictite from the Cambrian Longwangmiao Formation to the Ordovician Daqing Formation, the water-resisting rock series mainly composed of sand and mudstone with marine-terrestrial transitional facies from the Silurian Longmaxi Formation to the Devonian Hongyapo Formation, the water-bearing rock series composed of carbonate rock from the Devonian Qujing Formation to the Permian Maokou Formation, and the water-resisting rock series composed of the Permian Emei basalt. (3) The tectonic process forms a structural pattern of east-west differences in Zhaoyang district, controlling the distribution pattern of geological relics in this district. The reasons are as follows: the Indosinian Movement caused the overall uplift of the northeastern Yunnan into land; the Yanshan movement formed open and gentle folds in the west and relatively tight folds and large-scale faults in the east, resulting in east-west differences; the Xishan movement formed the Zhaotong intermountain basin, caused strong downward erosion of rivers, and controlled the direction of groundwater runoff, becoming a direct controlling factor for the formation of geological relics in Zhaoyang district. [ABSTRACT FROM AUTHOR]

Large species that are isolated for thousands of years on islands often evolve extreme degrees of dwarfism. Very little is known about physiological processes that accompany such extreme transitions in extinct dwarf species. We tested whether physiological cycles of bone maintenance (remodelling) in dwarf adult hippopotamuses correlate with insularity-driven body mass shifts that may occur due to variables such as ecological release from predation pressure and change in access to resources. We hypothesised that hippopotamuses with the smallest body size should show higher values of osteocyte lacunae, proxies for osteoblast proliferation during cycles of remodelling, when compared to relatively larger dwarf forms, as well as much larger mainland common hippopotamuses. We examined 20 ribs from three extinct Pleistocene Hippopotamus species spanning a gradient in body size: H. minor (~132 kg, Cyprus), H. creutzburgi (~398 kg, Crete), and H. antiquus (~3200 kg, mainland Greece). Ribs were selected because they reflect bone metabolic rates that are not completely clouded by factors such as biomechanics. Densities of osteocyte lacunae (Ot.Dn) were examined in 864 individual secondary osteons observed in histology sections. We found the highest average Ot.Dn in the H. minor ribs, intermediate Ot.Dn in the H. creutzburgi ribs, and the lowest Ot.Dn in the H. antiquus ribs. It appears that Ot.Dn distinctly separated these three species, possibly signifying a gradient in bone remodelling such that bone tissue optimises maintenance in the face of insularity-driven reduction of body size. We discuss hippopotamus rib bone microstructure and the utility of Ot.Dn in palaeontological analyses for elucidating intricate biological processes occurring in bone of insular fossil mammals. [ABSTRACT FROM AUTHOR]

Lumbar vertebrae are an important functional unit of the spine in mammals. Although the correlation between lumbar morphology and function in extant mammals is well known, the evolution of disparate lumbar morphology through the fossil record has remained unexplored. I sampled lumbar vertebrae from 100 fossil and extant mammals across a wide taxonomic range and categorized the morphology of these vertebrae with discrete morphological characters. I used marginal ancestral state reconstruction to model the evolutionary history of each character and calculated a retention index to assess homoplasy. I then compared these results to correlations between each character and body size, as a functional metric. Presence of anapophyses, a postzygapophyseal lamina, and xenarthrous articulations all showed high retention, indicating strong phylogenetic signal. Centrum length and transverse process angle showed low retention and strong correlation with body size. These results demonstrate that, although lumbar morphology is strongly controlled by function, phylogeny does have a notable influence. Furthermore, these data support the evolution of lumbar vertebrae along the stem to Theria, with ancestral therian vertebrae having had transverse processes rooted to the neural arch, posteriorly angled neural spines, and flat, horizontal zygapophyses. [ABSTRACT FROM AUTHOR]

The Palaeontology-Stratigraphy Museum is hosted by the Directorate for Heritage of the “Babeș-Bolyaiˮ University from Cluj-Napoca. Its collections were founded in the 19th century, then gradually enriched through donations of the professors and students, or by exchanges with other museums. They were initially used for teaching and research purposes and are nowadays available for the public as well. The sirenian fossils in the museum’s collection, even though are not many, represent an important heritage, a valuable tool in illustrating the Paleogene marine fauna of Romania and the worldwide fossils of these marine mammals. Today, the museum hosts 39 pieces of sirenian fossils. The aim of this article is an inventory of these fossils and the revision of the data referring to each piece. This paper includes the following data: the material, inventory numbers, the name of the locality where the fossil originated from, the stratigraphic unit, the geological age, the name of donor when available and, in few cases, measurements and short descriptions of the pieces, when necessary. [ABSTRACT FROM AUTHOR]

'Arambourg collection' is a collection of mainly mammal fossils from Axios Valley (Macedonia, Greece) made by the French geologist C. Arambourg during 1915–16. It is housed in the Muséum national d'Histoire naturelle of Paris. New excavations in Axios Valley during the last 50 years allowed the collection of many fossils and a new taxonomy of hipparions has been proposed. The revision of the hipparionine horses of this old collection based on the new taxonomy and an effort to correlate the old localities of Arambourg with the well dated new ones, found in the area, are given in this article. The available material from the different localities is fragmentary, mixed and in most cases poor without locality indications, preventing definite determinations.The following taxa have been recognised: H. phillipus, H. aff. mediterraneum; H. aff. proboscideum, and H. aff. macedonicum or H. aff. sithonis. Based on the fauna, lithology and the map of Arambourg, the old localities are correlated with the new lithostratigraphy and localities. The age of the old localities is late Vallesian-late Turolian (MN10-13) and agrees with the results taken from the new studies in the area. [ABSTRACT FROM AUTHOR]

Body mass (BM) is a fundamental variable for many paleobiological investigations that is challenging to accurately infer for species that lack living representatives and/or close morphological analogs. This study explores this issue using notoungulates, a diverse group of extinct South American herbivorous mammals with an extensive fossil record. We use a new dataset of 1,900+ extant mammal species (from ~80,000 specimens) to estimate notoungulate BM based on head-body length and a published dataset of 400+ species (~2,100 specimens) to estimate BM based on occipital condyle width. Condylobasal length, stylopod diameter and circumference, and neck length data are used to explore factors that can confound BM predictions. We estimate the following BM ranges for 10 osteologically well-characterized species and calculate similar ranges for 30 others known from less complete remains: Toxodontia: Thomashuxleya externa (80–120 kg), Homalodotherium cunninghami (250–350 kg), Scarrittia canquelensis (450–550 kg), Adinotherium ovinum (75–90 kg), Nesodon imbricatus (350–400 kg), and Toxodon platensis 1,000–1,200 kg); Typotheria: Interatherium robustum (1.9–2.0 kg), Miocochilius anomopodus (9–14 kg), Protypotherium australe (3.5–4.0 kg), and Pachyrukhos moyani (1.2–1.6 kg). We suggest that species such as these can be used as "calibration points" when inferring BM of species known from more limited remains. Discrepancies between our estimates and previously-published studies are primarily due to the distinctive craniodental morphology of notoungulates and the robust limb bones of toxodontians. There is significant, non-random error correlated with body habitus (i.e., being relatively robust or gracile) in many variables traditionally used to estimate BM, including femur circumference, and new methods are needed to compensate for this. [ABSTRACT FROM AUTHOR]

Advances in technology have equipped paleobiologists with new analytical tools to assess the fossil record. The functional traits of vertebrates have been used to infer paleoenvironmental conditions. In Quaternary deposits, birds are the second-most-studied group after mammals. They are considered a poor paleoambiental proxy because their high vagility and phenotypic plasticity allow them to respond more effectively to climate change. Investigating multiple groups is important, but it is not often attempted. Biogeographical and climatic niche information concerning small mammals, reptiles, and birds have been used to infer the paleoclimatic conditions present during the Late Pleistocene at San Josecito Cave (~28,000 14C years BP), Mexico. Warmer and dryer conditions are inferred with respect to the present. The use of all of the groups of small vertebrates is recommended because they represent an assemblage of species that have gone through a series of environmental filters in the past. Individually, different vertebrate groups provide different paleoclimatic information. Birds are a good proxy for inferring paleoprecipitation but not paleotemperature. Together, reptiles and small mammals are a good proxy for inferring paleoprecipitation and paleotemperature, but reptiles alone are a bad proxy, and mammals alone are a good proxy for inferring paleotemperature and precipitation. The current paleoclimatic results coupled with those of a previous vegetation structure analysis indicate the presence of non-analog paleoenvironmental conditions during the Late Pleistocene in the San Josecito Cave area. This situation would explain the presence of a disharmonious fauna and the extinction of several taxa when these conditions later disappeared and do not reappear again. [ABSTRACT FROM AUTHOR]

We describe three new Toxodontidae (Notoungulata) remains from Mendoza Province, west-central Argentina. One is a new mandible (IANIGLA-PV 993) collected at Huayquerías del Este, from the Huayquerías Formation (Late Miocene-earliest Pliocene). This finding adds to two other unpublished specimens from the area stored in old collections. MCNAM-PV 113 is a skull fragment from Huayquerías de San Carlos, lacking exact origin data, and MACN PV 14854 corresponds to associated upper and lower teeth from the so-called Bajada Grande locality, in Huayquerías del Este, from levels now assigned to the Bajada Grande Formation (Late Pliocene-Pleistocene). IANIGLA-PV 993 and MCNAM-PV 113 belong to Xotodon major. This species was described in 1914 based on cranial remains likely from levels now assigned to the Tunuyán Formation. Slight differences between IANIGLA-PV 993 and the holotype of X. major are attributable to intraspecific variation and their ontogenetic stage: smoother anteroventral mandibular angle; ascending ramus with blunt crest between the fossae for the zygomaticomandibularis and masseteric muscles; and tooth features (e.g., p4 with deeper grooves and slightly shorter teeth) that relate to a lesser wear degree. MCNAM-PV 113 shows nasals and upper teeth comparable with the holotype, although teeth are slightly less compressed. The temporal gap between levels yielding the holotype and IANIGLA-PV 993 is not reflected by our taxonomical interpretation. Finally, the specimen MACN PV 14854 is identified as Toxodon chapalmalensis, based upon its similarities with specimens from the Chapadmalal area, Buenos Aires Province, showing a correspondence with the Chapadmalalan Stage/Age of the Pampean Region. [ABSTRACT FROM AUTHOR]

A prominent hypothesis in the diversification of placental mammals after the Cretaceous–Palaeogene (K/Pg) boundary suggests that the extinction of non‐avian dinosaurs resulted in the ecological release of mammals, which were previously constrained to small body sizes and limited species richness. This 'dinosaur incumbency hypothesis' may therefore explain increases in mammalian diversity via expansion into larger body size niches, that were previously occupied by dinosaurs, but does not directly predict increases in other body size classes. To evaluate this, we estimate sampling‐standardized diversity patterns of terrestrial North American fossil mammals within body size classes, during the Cretaceous and Palaeogene. We find strong evidence for post‐extinction diversity increases in all size classes. Increases in the diversity of small‐bodied species (less than 100 g, the common body size class of Cretaceous mammals, and much smaller than the smallest non‐avialan dinosaurs (c. 400 g)) were similar to those of larger species. We propose that small‐bodied mammals had access to greater energetic resources or were able to partition resources more finely after the K/Pg mass extinction. This is likely to be the result of a combination of widespread niche clearing due to the K/Pg mass extinctions, alongside a suite of biotic and abiotic changes that occurred during the Late Cretaceous and across the K/Pg boundary, such as shifting floral composition, and novel key innovations among eutherian mammals. [ABSTRACT FROM AUTHOR]

Nitrogen isotopes are widely used to study the trophic position of animals in modern food webs; however, their application in the fossil record is severely limited by degradation of organic material during fossilization. In this study, we show that the nitrogen isotope composition of organic matter preserved in mammalian tooth enamel (δ15Nenamel) records diet and trophic position. The δ15Nenamel of modern African mammals shows a 3.7‰ increase between herbivores and carnivores as expected from trophic enrichment, and there is a strong positive correlation between δ15Nenamel and δ15Nbone-collagen values from the same individuals. Additionally, δ15Nenamel values of Late Pleistocene fossil teeth preserve diet and trophic level information, despite complete diagenetic loss of collagen in the same specimens. We demonstrate that δ15Nenamel represents a powerful geochemical proxy for diet that is applicable to fossils and can help delineate major dietary transitions in ancient vertebrate lineages. Enamel-bound nitrogen isotopes in modern and fossil mammal teeth preserve dietary and trophic level information. This novel geochemical archive can be used to reconstruct trophic niche in ancient ecosystems. [ABSTRACT FROM AUTHOR]

Postes Cave in SW Spain (Extremadura) displays a Holocene archaeostratigraphic sequence radiocarbon-dated to between c. 8.5–4 cal kyr BP (Mesolithic-Chalcolithic). The sediments collected at two areas within the cave yielded small mammal remains belonging to eleven species of rodents, 'insectivores', lagomorphs and chiropterans. This small mammal fossil assemblage is one of the few known to date in the southwest of the Iberian Peninsula. Preliminary taphonomic analysis and previously published data suggest that the remains were accumulated by the predatory activity of Eurasian eagle owls and small to medium-sized carnivores such as red foxes. The palaeoenvironmental and palaeoclimatic reconstructions performed show stable conditions with slight variations during its time span, suggesting an initial scenario of open forested habitats during the Mesolithic and Neolithic which progressively decreased in favour of more open habitats during the Chalcolithic coinciding with human-induced changes of the landscape and with the aridification trend of this period. The presence of Microtus cabrerae and Crocidura suaveolens in the assemblage is noteworthy since they are now extinct in this region. The plausible causes and the processes of these extirpations are discussed. [ABSTRACT FROM AUTHOR]

The upper diluvial boundary is difficult to determine in some areas, such as the Arctic coast of North America and the fossil locations of Australian marsupials. An even more difficult area is the top layers of sedimentary rocks of the southern and central High Plains where numerous mammal and other fossils are buried. Despite evidence of a post-Flood paleoenvironment of Agate Fossil Beds National Monument and Ashfall Fossil Beds State Historic Park, they likely are within the Ogallala Group (two or more formations). The Ogallala Group is widespread and thin and was spread hundreds of kilometers east. About half of its top was subsequently eroded. Quartzite rocks from the Rocky Mountains are marked with percussion marks indicating torrential flow. Some quartzite cobbles and boulders have spread 800 km from their source in the southern Rocky Mountains and are found on valley interfluves in central Texas. Most of the fossils in the Group are of animals not living today or during the Ice Age. It is difficult to explain how many millions of animals were buried in the southern and central High Plains with a post-Flood scenario. It is easier to explain that the animals were buried during the Genesis Flood. The apparent post-Flood features can be explained by the BEDS Model. Grass seed fossils associated with a rhino could be because grass fossils are very abundant in the Ogallala Formation. [ABSTRACT FROM AUTHOR]

Taxonomic decisions made by palaeontologists are often based on a few morphological features preserved in the fossil material. This practice may sometimes lead to the description of new species based on single specimens, which are, in fact, extreme or aberrant morphological variants of known taxa. Ancient DNA (aDNA) analysis of the Late Pleistocene specimens from the archaeological site Petits Guinards (Creuzier-la-Vieux, Allier, France), described as a new vole Microtus (Sumeriomys) bifrons, did not confirm the species distinctness of the studied population. The genetically examined specimens belonged to Stenocranius anglicus and/or Microtus arvalis, the dominant species at the site. Our findings show that it is risky to describe new fossil taxa on the basis of phenotypic outliers or morphologically aberrant, rare specimens that do not fall within the previously known population variability. We also highlight the importance of ancient DNA in resolving taxonomic and nomenclature problems and classifying fossil mammals of the Late Pleistocene age. [ABSTRACT FROM AUTHOR]

This study examines the suitability of the authigenic 10Be/9Be dating method to the dating of the deposits of an incising river, taking as an example the Nová Vieska river terrace, which accumulated during the neotectonic inversion of the Danube Basin (western Slovakia). The succession was formed by a wandering river with minor preservation of proximal floodplain muds. The frequent occurrence of mud intraclasts reflects significant input of eroded material from underlying, older successions. The ages of 13 authigenic 10Be/9Be dating samples formed three groups: (1) samples from below the base of the river terrace yielded dates of ~4.13–3.70 Ma (including uncertainties); (2) muddy intraclasts from the river terrace gave an age range of ~2.79–1.96 Ma; and (3) in situ muddy layers had ages in the range of ~1.91–1.39 Ma. The large mammal fossil assemblage from channel thalweg deposits yielded a biostratigraphic age of ~3.6–2.2 Ma, matching the age of intraclasts, and thus emphasising the redeposited origin of those fossils. The relatively wide range of authigenic 10Be/9Be dating ages is interpreted as a result of the redeposition of mud from older strata on three scales: decimetre‐scale intraclasts, millimetre‐scale rip‐up clasts mixed into the newly formed beds, and formation of two authigenic rims with different age and 10Be/9Be records around individual particles. Considering these observations, an age range of in situ layers of ~1.91–1.39 Ma is proposed as the depositional age of the river terrace, with the most probable age falling within the most recent part of this interval. The effect of redeposition is thus shown to be potentially limiting to the application of authigenic 10Be/9Be dating to incising rivers, and stands in marked contrast to aggrading river settings, where redeposition of older sediments is limited and the degree of 10Be/9Be variability is low. [ABSTRACT FROM AUTHOR]

Stable isotope palaeoecology of fossil mammals is a key research tool for understanding the environmental context of hominin evolution in the Plio-Pleistocene of Africa. Well studied mammal groups include bovids, suids, equids, proboscideans and primates, but to date there has been no in-depth study of modern and fossil carnivores. Here we produce an Africa-wide oxygen and carbon enamel isotope dataset for modern carnivores and compare it with fossil carnivore data sampled from the Plio-Pleistocene Omo Group of the Turkana Basin, Kenya. Comparison of modern carnivore carbon isotopes with satellite images of land cover indicates that carnivore δ13C is related to the proportion of woody cover in the local environment. Modern carnivore oxygen isotopes are strongly influenced by the δ18O of meteoric water, through drinking from standing water and through prey body fluids. Carbon isotope data from fossil carnivores shows close agreement with palaeovegetation reconstructions from δ13C of palaeosol carbonates from the same geological Members, and a similar long-term trend in δ13C values through time (4 Ma to 1 Ma), reflecting a gradual increase in the proportion of C 4 grasses in the Turkana Basin. This increase in the δ13C of large carnivores is consistent with the evidence from other mammalian groups for an increase in the proportion of grazers compared to browsers and mixed feeders during this time interval. Two distinct trends within oxygen versus carbon isotope space indicates that the fossil carnivores lived during two distinct climatic regimes – one in which palaeo-lake Turkana was freshwater, and one in which the lake resembled its modern-day hyperalkaline state. These two climatic states most likely represent the end-members of precessionally-driven rainfall extremes over the Ethiopian Highlands. This indicates that each studied faunal assemblage from the Omo Group is a time- and climate-averaged palimpsest; this has significant implications for the interpretation of environmental signals and community palaeoecology derived from Turkana Basin fossil mammals, including early hominins. [ABSTRACT FROM AUTHOR]

Renewed surveys focused on Quaternary mammal remains were conducted during the 2019 Batu Caves Scientific Expedition by engaging members from the general public. Survey results added one previously unreported fossil site (Gatal Bawah Cave) and enriched the faunal composition of a Late Pleistocene site (Cistern Cave). An updated faunal list reveals a greater palaeo-diversity of mammals in Batu Caves area than is at present. [ABSTRACT FROM AUTHOR]

We propose a quantitative approach for categorising mammalian diets based on the taxonomy of food items and parts consumed (the form of food). Our analysis covers 82% of the mammalian species alive today. The diet information comes from different data sources—textbooks, datasets and peer-reviewed literature and includes a transformation of narrative quantitative data into qualitative data. We link a database on nutrient composition of diet items of the quantitative diet data and analyse the distribution of macronutrients of diets across taxonomic groups and map them to the dental morphology of the eaters. The results show associations between dental complexity and the concentrations of some nutrients. Our analysis highlights omnivory as a multi-faceted concept—there are many kinds of omnivores within the dietary space we report. The developed dataset and the proposed approach relating the chemical composition of diets offers a basis for future comparative studies of living and fossil mammals. With this study, we make the accompanying large-scale dietary data publicly available online (https://www.mammalbase.net). [ABSTRACT FROM AUTHOR]

Paleontological remains retrieved from permafrost represent the most informative records of Pleistocene ecosystems. Different levels of past microbial activity affecting fossil material preservation are presented for two selected bone samples--an almost intact Bison sp. metacarpus (45.0 ± 5.0 14C ka BP) and a weathered Equus sp. metacarpus (37.8 ± 1.7 14C ka BP) from the recently exposed cryogenic geo-contexts in the Yana River basin, NE Yakutia. Diagenetic changes in bone porosity and chemical composition as a result of the past microbial activity were investigated by multiple analytical methods. In the bison bone, which was permafrost-sealed shortly after death of the animal and conserved for ca. 45 ka in a frozen state in a cryolithic formation, only superficial microbial degradation processes were detected. Progressive microbial attacks characterize the horse bone, which was exposed to MIS 3 sub-aerial biogenic decay and modern surficial weathering. This is evidenced by extensive bacterial micro-boring with the typical focal destructions, an increase in microbial porosity, and de-mineralized osseous zones due to waterlogged and poorly oxygenated past depositional conditions. New information contributes to better understanding of the diagenesis particularities and the associated chemical and biological agents of the fossil osteological assemblages with respect to their taphonomic and paleoenvironmental implications. [ABSTRACT FROM AUTHOR]

Micromammalian fauna and palynological spectra have been studied in two cave-type localities of the Iordanskogo Ravine in the Northern Urals (Pechora-Ilych Nature Reserve): the Studyony canopy and the Filin niche. The cave sedimentation conditions have been reconstructed on the basis of the paleofauna and palynological data. The fossil small mammal assemblages and the spore–pollen spectra are indicative of the spread of shrubby swampy tundra with forest islands in the Upper Pechora region at the end of the Middle Valdai (Byzovaya Interstadial, MIS 3) and tundra-steppe landscapes under the progressive climate drying during the Last Glacial Maximum. During the Late Glacial, tundra-like shrubs prevailed, and the climate was much colder than the recent one. The rodent fauna was dominated by tundra and tundra-steppe species. In the Early Holocene, the climate warming lowered the role of xerophytic shrubs, replaced by birch–spruce–pine forests. In the rodent fauna, the proportion of tundra and tundra-steppe species decreased by more than a factor of three. During the Late Holocene, dark coniferous forests with fir and Siberian pine became widespread. Rodent associations acquired a typical taiga appearance: the forest inhabitants accounted for more than half of all remains (60–80%), while the tundra species were absent. [ABSTRACT FROM AUTHOR]

The taphonomic histories of five cave deposits in Brazil were interpreted, focusing on the accumulation and taphonomic modes. These caves, Complexo Suíço, F3, Toca das Onças, Lapa dos Peixes and Gruna das Três Cobras, show evidence of remains being accumulated through entrapping, sheltering, and water transportation. Cluster Analysis revealed a predominance of irregular breaks and low stages of weathering as the primary taphonomic mode, along with lack of corrosion and abrasion. Factor Analysis also indicated that incrustation played a major role in distinguishing between the deposits. The remains in F3, Toca das Onças, Lapa dos Peixes, and Gruna das Três Cobras caves experienced similar preservation conditions, including fragmentation from reworking, block collapses, exposure to acidified rainwater, incrustation and abrasion from water-borne sediments, and corrosion due to bat guano and acidified water. • The causes of deaths for most animals were starvation and dehydration. • The absence of taphonomic features leads the main taphonomic mode for all caves. • Incrustation is the primary feature allowing the differentiation between the five cave fossil assemblages. • Time of exposure and climate variation control directly control the formation of taphonomic features. [ABSTRACT FROM AUTHOR]

In the last decades, the impact of Darwin's legacy has been emphasized in many scientific fields. Nevertheless, there are still lesser-explored aspects of his life as researcher that deserve attention, such as his role as taphonomist. In this context, we highlight here this relevant facet of Darwin's investigations. During his voyage on the H.M.S. Beagle, Darwin collected numerous vertebrate fossils from South America. Particularly, in the Argentine Pampas he recorded information on the paleontology, stratigraphy, and sedimentology of different late Cenozoic fossiliferous sites. He also made observations on the preservation features of bone remains and the mechanisms that favored their fossilization, aspects currently included in the taphonomy field. In this frame, the information published in Geological Observations on South America regarding the fossils from Monte Hermoso and Punta Alta sites and his comments about the "imperfection of the geological record" on the Origin of the Species , are particularly noteworthy as an indicator of his interest in the relationship between the environmental context of preservation and the taphonomic features of bone remains. After 150 years, his scientific work continues to fascinate us. Darwin's keen eye for detail and his curiosity about the history of each fossil, about a century before taphonomy was born as a discipline, can indeed be likened to that of a Crime Scene Investigator (CSI) in some regards, reconstructing the taphonomic histories of both single remains and whole assemblages. • We highlight Darwin's profile as taphonomist, prior the discipline definition. • Darwin made taphonomic observations on mammal fossils from Argentine Pampas. • Darwin used modern analogues to interpret the fossil record. • Darwin had a particular interest in knowing the whole history of recovered fossil. [ABSTRACT FROM AUTHOR]

Biotic homogenization—increasing similarity of species composition among ecological communities—has been linked to anthropogenic processes operating over the last century. Fossil evidence, however, suggests that humans have had impacts on ecosystems for millennia. We quantify biotic homogenization of North American mammalian assemblages during the late Pleistocene through Holocene (~30,000 ybp to recent), a timespan encompassing increased evidence of humans on the landscape (~20,000–14,000 ybp). From ~10,000 ybp to recent, assemblages became significantly more homogenous (>100% increase in Jaccard similarity), a pattern that cannot be explained by changes in fossil record sampling. Homogenization was most pronounced among mammals larger than 1 kg and occurred in two phases. The first followed the megafaunal extinction at ~10,000 ybp. The second, more rapid phase began during human population growth and early agricultural intensification (~2,000–1,000 ybp). We show that North American ecosystems were homogenizing for millennia, extending human impacts back ~10,000 years. Biotic homogenization, which is increased similarity in the composition of species among communities, is rising due to human activities. Using North American mammal fossil records from the past 30,000 years, this study shows that this phenomenon is ancient, beginning between 12,000 and 10,000 years ago with the extinction of the mammal megafauna. [ABSTRACT FROM AUTHOR]

The fossil record of marine mammals from the upper Pliocene of the western coast of South America is poorly known, hindering our knowledge about how and when marine mammal faunas attained their modern distribution in the area. Here, we describe a new marine mammal assemblage from the Horcón Formation (upper Pliocene), located in the Valparaíso Region of central Chile. The material reported comprises postcranial remains of an indeterminate seal (Phocidae), Delphinoidea vertebrae, and mysticete elements (still in the field). The Phocidae remains constitute the youngest pre-Pleistocene record of this family in South America, providing new information regarding the timing for the establishment of the modern diversity and distribution of pinnipeds in the Southern Hemisphere. Furthermore, the pinniped and cetacean remains reported indicate that the marine mammal assemblage from the upper Pliocene along central Chile was composed of a mixture of modern and extinct taxa. [ABSTRACT FROM AUTHOR]

Background: The leporid lagomorphs (rabbits and hares) are adapted to running and leaping (some more than others) and consequently have unique anatomical features that distinguish them from ochotonid lagomorphs (pikas) and from their rodent relatives. Two traits that have received some attention are fenestration of the lateral wall of the maxilla and facial tilting. These features are known to correlate with specialised locomotory form in that the faster running species will generally have fenestration that occupies the dorsal and the anteroventral surface of the maxillary corpus and a more acute facial tilt angle. Another feature is an intracranial joint that circumscribes the back of the skull, thought to facilitate skull mobility. This joint separates the anterior portion of the cranium (including the dentition, rostrum and orbit) from the posterior portion of the cranium (which encompasses the occipital and the auditory complex). Aside from the observation that the intracranial joint is absent in pikas (generalist locomotors) and appears more elaborate in genera with cursorial and saltatorial locomotory habits, the evolutionary history, biomechanical function and comparative anatomy of this feature in leporids lacks a comprehensive evaluation. Methodology: The present work analysed the intracranial joint, facial tilting and lateral fenestration of the wall of the maxilla in the context of leporid evolutionary history using a Bayesian inference of phylogeny (18 genera, 23 species) and ancestral state reconstruction. These methods were used to gather information about the likelihood of the presence of these three traits in ancestral groups. Results: Our phylogenetic analyses found it likely that the last common ancestor of living leporids had some facial tilting, but that the last common ancestor of all lagomorphs included in the dataset did not. We found that it was likely that the last common ancestor of living leporids had fenestration that occupies the dorsal, but not the anteroventral, surface of the maxillary corpus. We also found it likely that the last common ancestor of living leporids had an intracranial joint, but that the last common ancestor of all living lagomorphs did not. These findings provide a broader context to further studies of evolutionary history and will help inform the formulation and testing of functional hypotheses. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study of rare earth element (REE) fractionation trends in Quaternary mammal remains with the aim to test stratigraphic provenance. The primary aim was to find a solution to the problem of the formation of small mammal disharmonious associations, which is closely connected to the problem of diagnostics of redeposited paleontological material. REE were analyzed from the tooth enamel of small mammal fossils and sediments collected from five stratigraphic units (Ust‐Oda section of Upper Pleistocene terrestrial sediments, Fore‐Baikal area, Siberia). The Ust‐Oda is currently the only known section in the region where a fixed stratigraphic sequence of the Late Pleistocene to Holocene marine isotopic stages (MIS 5–1) occurs. The results for REE signatures of tooth enamel enable us to draw conclusions regarding changes in physical and chemical environmental conditions during diagenesis and afford the possibility of applying geochemical factors signifying REE fractionation to sample classification. This, in turn, allowed us to establish that some small mammal remains found in sediments belonging to the Ust‐Oda section have been redeposited. [ABSTRACT FROM AUTHOR]

Simple Summary: Two independent research groups led by Olivares (Spain) and Lowenstein (USA) investigated the immunological reactions of proteins extracted from the controversial Orce skull (VM-0), a 1.3-million-year-old fossil found at the Venta Micena site in Orce, Granada (Spain) and initially believed to come from an unidentified hominin. Work by both groups with polyclonal and monoclonal antibodies showed that proteins from this fossil reacted most strongly to antibodies against modern human proteins. Other hominin and mammal fossils from Venta Micena were also studied. Proteomics methods can identify amino acid sequences in fossil proteins, thus making it possible to determine the ascription or proximity of a fossil to other species. Before mass spectrometry was used to study fossil proteins, earlier studies used antibodies to recognize their sequences. Lowenstein and colleagues, at the University of San Francisco, pioneered the identification of fossil proteins with immunological methods. His group, together with Olivares's group at the University of Granada, studied the immunological reactions of proteins from the controversial Orce skull fragment (VM-0), a 1.3-million-year-old fossil found at the Venta Micena site in Orce (Granada province, southern Spain) and initially assigned to a hominin. However, discrepancies regarding the morphological features of the internal face of the fossil raised doubts about this ascription. In this article, we review the immunological analysis of the proteins extracted from VM-0 and other Venta Micena fossils assigned to hominins and to other mammals, and explain how these methods helped to determine the species specificity of these fossils and resolve paleontological controversies. [ABSTRACT FROM AUTHOR]

The Venta del Moro site (Valencia, Spain) is especially known for its rich content in Late Miocene fossil mammals but it also holds other fossil vertebrates, invertebrates and plants. A micropalaeontological study of a 70-cm long sedimentary section carried out in the lacustrine beds of the site has yielded 2 foraminifer, 7 thecamoebian and 19 ostracod taxa (two of these last probably new species). A constrained cluster analysis allowed the recognition of three consecutive zones based on their micropalaeontological content. The variation of the microfossil assemblages closely matches lithology and reflects environmental changes in a palaeolake that was subject to a gradual drying process. Anoxic bottom conditions at the base of the sequence (Zone 1) prevented the occurrence of aerobic benthic microorganisms. Later, the appearance of ostracods and thecamoebians (Zone 2) documents the increasing oxygenation of the lake and suggests a permanent freshwater to slightly brackish lake with low temperature and stream influence. The dominance of foraminifers and the changes in the thecamoebian and ostracod assemblages in the upper part of the sequence (Zone 3) reflect more stable and oxygenised conditions and probably increasing temperature and evaporation in oligohaline temporary waters, during the final drying phase of the lake. [ABSTRACT FROM AUTHOR]

A fossil‐bearing locality near Padhri village, Dhok Pathan, 55 km away from the tehsil Dina, Jhelum District, in the Potwar Plateau, Middle Siwaliks, Punjab, northern Pakistan, is significantly rich in mammalian fossils. This site has provided an abundant mammalian fossil fauna of Late Miocene age from the Dhok Pathan Formation (Fm.). The recovered material belongs to four families: Equidae (horses), Rhinocerotidae (rhinos), Bovidae (cows), and Suidae (pigs). We discovered a new skull of hipparionine Hipparion theobaldi from this locality along with 22 specimens from the associated assemblage of fossil mammals. The recovered material includes seven other species: the aceratheriine Chilotherium intermedium, boselaphines Tragoportax punjabicus, Selenoportax vexillarius, Pachyportax latidens, the antelope Gazella lydekkeri and suinine Propotamochoerus hysudricus. The specimens are isolated teeth, fragments of maxilla, mandibles and horn cores. The Dhok Pathan Fm. is generally composed of claystone, siltstone and sandstone beds and, based on the mammalian fauna, the Padhri fossil locality is dated as Late Miocene. Thi99s formation was deposited in a subtropical paleoenvironment and the predominance of fossil bovids indicates extremely moist conditions with small but frequent standing water bodies. [ABSTRACT FROM AUTHOR]

Ferns are important components of the biodiversity of wet forests across Canada, and the fossil record offers insights into the origins of fern diversity and biogeography. In 1967, Driftwood Canyon Provincial Park in north-central British Columbia was declared an Eocene Epoch plant, insect, fish, bird, and mammal fossil site of national scientific significance to preserve the Driftwood Creek fossil beds. The fossil plants from this important fossil site remain largely unknown. Here, a first record of a beech fern from the Eocene of British Columbia--morphologically comparable to the Phegopteris connectilis group--is illustrated, further revealing the past biodiversity of ancient British Columbia. The absence of sori and other key anatomical characters prevents definitive identification. Today, the circumpolar to temperate species Northern Beech Fern (Phegopteris connectilis) is widespread across British Columbia, occurring in wet coniferous forests; other members of the P. connectilis group also occur in temperate climates. [ABSTRACT FROM AUTHOR]

The Cretaceous–Paleogene (KPg) boundary, one of Earth's five major extinction events, occurred just before the appearance of Placentalia in the fossil record. The Gobi Desert, Mongolia and the Western Interior of North America have important fossil mammals occurring just before and after the KPg boundary (e.g. Prodiacodon, Deltatheridium) that have yet to be phylogenetically tested in a character‐rich context with molecular data. We present here phylogenetic analyses of >6000 newly scored anatomical observations drawn from six untested fossils and added to the largest existing morphological matrix for mammals. These data are combined with sequence data from 27 nuclear genes. Results show the existence of a new eutherian sister clade to Placentalia, which we name and characterize. The extinct clade Leptictidae is part of this placental sister clade, indicating that the sister clade survived the KPg event to co‐exist in ancient ecosystems during the Paleogene radiation of placentals. Analysing the Cretaceous metatherian Deltatheridium in this character‐rich context reveals it is a member of Marsupialia, a finding that extends the minimum age of Marsupialia before the KPg boundary. Numerous shared‐derived features from multiple anatomical systems support the assignment of Deltatheridium to Marsupialia. Computed tomography scans of exquisite new specimens better document the marsupial‐like dental replacement pattern of Deltatheridium. The new placental sister clade has both Asian and North American species, and is ancestrally characterized by shared derived features such as a hind limb modified for saltatorial locomotion. [ABSTRACT FROM AUTHOR]

Cranial endocasts are one of the most direct tools available to obtain information about the endocranial cavity of fossil mammals, but few anatomical comparisons have analyzed endocranial data within a phylogenetic framework. Our study combines analyses of new digital endocasts from high-resolution X-ray micro-computed tomography (µCT) for two notoungulates, Cochilius sp. and Notostylops murinus, with data from published anatomical descriptions and endocasts (prior µCT digital endocasts and natural and extracted plaster endocasts), resulting in 22 endocranial characters (11 new) scored on 20 notoungulates and five outgroups. These data permitted a comparative study of cranial endocasts of notoungulates, an enigmatic group of extinct South American mammals, shedding light on several important issues concerning their phylogenetic relationships. The new endocranial data were integrated into a craniodental and postcranial matrix, resulting in 259 characters across 65 taxa, the most comprehensive character and taxon sampling to date and the only one including a substantial suite of endocranial characters. We further performed ancestral state reconstructions for endocranial characters using parsimony optimization on the resulting phylogenetic trees. Body mass estimates and endocranial volumes were used to calculate Encephalization Quotients (EQs) and Phylogenetic Encephalization Quotients (PEQs), which then were optimized onto the phylogenies. Endocast data from ancestral character state reconstructions bear on relationships among meridiungulates, revealing that many endocast characters may be synapomorphies for Notoungulata and other clades within the group. Notoungulates, in general, display relatively low EQs when compared with Holarctic herbivorous mammals, potentially due to their long history of evolution in isolation in South America during the Cenozoic. [ABSTRACT FROM AUTHOR]

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• New land vertebrate fossils discovered at the El Abra outcrop in Matanzas, Western Cuba, provide valuable insights into the Late Pliocene-Early Pleistocene Greater Antillean land mammal fossil record. • Previously undocumented capromyine rodent dental remains significantly enrich the insular Caribbean's terrestrial vertebrate fossil record. • Partially closed roots observed in the reported El Abra capromyine specimen, a feature not previously reported in Cuban taxa, suggest possible affinities with Hexolobodon from Hispaniola. • Strontium isotope analysis (87Sr/86Sr) and foraminiferal biostratigraphy indicate a depositional age between the Late Pliocene and Early Pleistocene, but the reworking of fossils suggests that the vertebrate remains could be older. • The findings suggest complex biogeographic patterns of vertebrate dispersal and diversification in the Caribbean, emphasizing the importance of addressing gaps in the fossil record and the impacts of recent extinctions on the region's biodiversity. [ABSTRACT FROM AUTHOR]

The Qaidam Basin in the northern Tibetan Plateau is currently arid, but may have had a semi-humid to semi-arid climate in Miocene times, as suggested by pollen and isotopic data; however, the lack of macroscopic fossils hinders more precise paleoclimatic calibration. In this paper, we report fossil leaves with insect damage from a late Miocene layer (HT-5) in the Huaitoutala section dated ∼11.4 Ma, and compare them with records from a middle Miocene layer (HT-1) dated ∼12.7 Ma. Results show that damage diversity dropped from 36 types in HT-1 to 24 types in HT-5, suggesting a fall in mean annual temperature. Damage frequency decreased from 70 % in HT-1 to 32 % in HT-5, pointing to a drop in the coldest month temperature. Moreover, a slight fall in the diversity of mining damage, from 5 types in HT-1 to 4 types in HT-5, suggests a shift towards a slightly more arid climate from the middle to late Miocene. The flora from HT-5 is composed mainly of Betulaceae, Populus , Ulmus , and shrubs. Based on the distribution of these taxa in modern vegetation, the climate was probably semi-humid, not entirely arid during the late Miocene. These results are corroborated by fossil mammal data from the same section. Therefore, despite a cooling and drying trend from the middle to late Miocene, the climate of the Qaidam Basin was not as extremely arid as today. • New discovery of the Miocene plant-insect interactions in the Tibetan Plateau; • The comparison of the insect damage data from the same site but different layers; • The Miocene cooling and drying climate trend based on the plant-insect indicators. [ABSTRACT FROM AUTHOR]

Located in the Northeast of Brazil, the city of Paripiranga, State of Bahia, is situated in a karst region called Supergrupo Canudos. The locality boasts a high number of natural cavities, some of which contain Pleistocene mammal fossils and remains of contemporary vertebrates. The cave locally known as Furna do Cazuza is a deep natural cavity in Proterozoic limestone, with a vertical entrance of 16 m in depth, resembling an abyss, serving as natural traps for many animals, especially mammals. The cave has a large area at its entrance, with a significant influx of sediment and a considerable quantity of bones, some of which have already been collected. The collected bone material (appendicular and part of a skull) belongs to three individuals: an armadillo and two giant ground sloths. The osteoderms were attributed to the Pampatheriidae Holmesina sp., and the most abundant bone material to the Megatheriidae Eremotherium laurillardi and the Scelidotheriidae Catonyx cuvieri. This study presents the largest number of bones of C. cuvieri attributed to a single individual in a cave. As paleontological research advances, the understanding of the diversity of the past fauna during the Pleistocene in the municipality of Paripiranga and the surrounding region continues to expand. The caves are still under study, and their fossiliferous richness has not been fully measured and identified. • Solid description of fossils in Furna do Cazuza Cave. • The addition of three new taxa - E. laurillardi , Holmesina sp. and the confirmation of C. cuvieri - to the paleobiodiversity. • The most complete Catonyx cuvieri skeleton found in the municipality of Paripiranga to date. • Amplification of the paleobiogeography of extincted taxons. [ABSTRACT FROM AUTHOR]

Understanding the climatic drivers of environmental variability (EV) during the Plio-Pleistocene and EV's influence on mammalian macroevolution are two outstanding foci of research in African paleoclimatology and evolutionary biology. The potential effects of EV are especially relevant for testing the variability selection hypothesis, which predicts a positive relationship between EV and speciation and extinction rates in fossil mammals. Addressing these questions is stymied, however, by 1) a lack of multiple comparable EV records of sufficient temporal resolution and duration, and 2) the incompleteness of the mammalian fossil record. Here, we first compile a composite history of Pan-African EV spanning the Plio-Pleistocene, which allows us to explore which climatic variables influenced EV. We find that EV exhibits 1) a long-term trend of increasing variability since ~3.7 Ma, coincident with rising variability in global ice volume and sea surface temperatures around Africa, and 2) a 400-ky frequency correlated with seasonal insolation variability. We then estimate speciation and extinction rates for fossil mammals from eastern Africa using a method that accounts for sampling variation. We find no statistically significant relationship between EV and estimated speciation or extinction rates across multiple spatial scales. These findings are inconsistent with the variability selection hypothesis as applied to macroevolutionary processes. [ABSTRACT FROM AUTHOR]

We suggest that mammalian endothermy was established amongst Middle Jurassic crown mammals, through reviewing state‐of‐the‐art fossil and living mammal studies. This is considerably later than the prevailing paradigm, and has important ramifications for the causes, pattern, and pace of physiological evolution amongst synapsids. Most hypotheses argue that selection for either enhanced aerobic activity, or thermoregulation was the primary driver for synapsid physiological evolution, based on a range of fossil characters that have been linked to endothermy. We argue that, rather than either alternative being the primary selective force for the entirety of endothermic evolution, these characters evolved quite independently through time, and across the mammal family tree, principally as a response to shifting environmental pressures and ecological opportunities. Our interpretations can be tested using closely linked proxies for both factors, derived from study of fossils of a range of Jurassic and Cretaceous mammaliaforms and early mammals. [ABSTRACT FROM AUTHOR]

Paleogene hyperthermals, including the Paleocene–Eocene Thermal Maximum (PETM) and several other smaller events, represent global perturbations to Earth's climate system and are characterized by warmer temperatures, changes in floral and faunal communities, and hydrologic changes. These events are identified in the geologic record globally by negative carbon isotope excursions (CIEs), resulting from the input of isotopically light carbon into Earth's atmosphere. Much about the causes and effects of hyperthermals remains uncertain, including whether all hyperthermals were caused by the same underlying processes, how biotic effects scale with the magnitude of hyperthermals, and why CIEs are larger in paleosol carbonates relative to marine records. Resolving these questions is crucial for a full understanding of the causes of hyperthermals and their application to future climate scenarios. The primary purpose of this study was to identify early Eocene hyperthermals in the Fifteenmile Creek area of the south-central Bighorn Basin, Wyoming, USA. This area preserves a sequence of fluvial floodplain sedimentary rocks containing paleosol carbonates and an extensive record of fossil mammals. Previous analysis of faunal assemblages in this area revealed two pulses of mammal turnover and changes in diversity interpreted to correlate with the ETM2 and H2 hyperthermals that follow the PETM. This was, however, based on long-distance correlation of the fossil record in this area with chemostratigraphic records from elsewhere in the basin. We present new carbon isotope stratigraphies using micrite δ13C values from paleosol carbonate nodules preserved in and between richly fossiliferous mammal localities at Fifteenmile Creek to identify the stratigraphic positions of ETM2 and H2. Carbon isotope results show that the ETM2 and H2 hyperthermals, and possibly the subsequent I1 hyperthermal, are recorded at Fifteenmile Creek. ETM2 and H2 overlap with the two previously recognized pulses of mammal turnover. The CIEs for these hyperthermals are also somewhat smaller in magnitude than in more northerly Bighorn Basin records. We suggest that basin-wide differences in soil moisture and/or vegetation could contribute to variable CIE amplitudes in this and other terrestrial records. [ABSTRACT FROM AUTHOR]

Wonderwerk Cave, in South Africa, is an exceptional site that has yielded a large collection of small mammal fossils in a stratigraphic sequence reaching back ca. 2 million years. Taphonomic studies undertaken to date, show that Tytonidae (likely Tyto alba) was the dominant predator during the Earlier Stone Age. They produced masses of pellets that formed a dense carpet-like surface that covered the cave floor at intervals throughout the sequence. This paper compares the taphonomic signatures of five different Earlier Stone Age small mammal assemblages from Wonderwerk Cave, including assemblages not studied before, as well as a modern pellet assemblage collected from inside the cave. These samples were examined using taphonomic signatures, bone density and spatial distribution which confirm that the main predator in all periods of cave occupation were members of the Family Tytonidae, most likely Barn owls. The Wonderwerk small mammals have enabled us to clarify site formation processes and confirm that there was no transport or mixing of fossils, neither spatially (re-sedimentation) nor chronologically (reworking). This has confirmed the integrity of the stratigraphic sequence in the cave, reinforcing interpretations of palaeoecology, and elucidating intensity of occupation by hominins versus predators, and the behaviour of the predators vis a vis their prey. [ABSTRACT FROM AUTHOR]

The Ponte Galeria area within the city of Rome has yielded numerous fossiliferous localities that represent a reference point for the study of the European Middle Pleistocene ecosystems. Within Ponte Galeria a rich collection of fossil mammals has been unearthed from Cava di Breccia – Casal Selce 2 (MIS 15) thus the site represents an optimal laboratory to investigate the palaeoenvironments of a defined territory during the Middle Pleistocene. We investigate the feeding behaviours of the ungulate community of Cava di Breccia – Casal Selce 2 to reconstruct the MIS 15 habitats and also compare the data with those of the nearby site of Fontana Ranuccio (MIS 11) which shares similar faunal composition with Cava di Breccia – Casal Selce 2 to test if ungulates occupied the same niches during two different interglacials. Open habitats with scattered woodlands characterised the Ponte Galeria area during MIS 15, whereas woodlands were more widespread during MIS 11 at Fontana Ranuccio. Ungulates display similar diets in both localities, suggesting that cervids, large bovids and equids adopted the same niche partitioning strategies during both interglacials. [ABSTRACT FROM AUTHOR]