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Fossils from natural tanks can contribute to the paleoenvironmental interpretation of the Brazilian Intertropical Region (BIR), an important study area for the Quaternary in South America. In this paper we present results of δ13C and δ18O for Eremotherium laurillardi (δ13C = −4.6 ‰, δ18O = 33.0 ‰), Toxodon platensis (δ13C = −3.8 ‰, δ18O = 35.5 ‰), and Notiomastodon platensis (δ13C = −2.9 ‰, δ18O = 31.6 ‰) from Zabelê tank, compared to other localities, suggesting that these taxa had a mixed-feeder diet with a higher consumption of C 4 plants (p i > 60%), living in a transition zone between woodland savannah and open savannah. The Zabelê tank, northeastern Brazil, presents Optically Stimulated Luminescence ages ranging from 41.2 to 30.4 ky (Lujanian Stage/Age; Late Pleistocene). The origin of the fossiliferous layer through debris flow suggests short periods of intense rainfall under drier climatic conditions. Compared to other locations in the BIR, Zabelê documented a drier climate (δ18O = 31.6–33.4 ‰), which preceded the last glacial maximum. These new isotopic data to OSL ages associated with previous data from the BIR contribute to the understanding of the paleoecology and paleoenvironment dynamics of South America. • New δ13C and δ18O for the three most studied taxa from the Quaternary of the BIR. • These taxa had a mixed-feeder diet with higher consumption of C 4 grasses. • These taxa inhabited a transition zone between arboreal to open savanna. [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]

The paleontological collection of the Museo Municipal de Ciencias Naturales "Carlos Ameghino" (MCA, Mercedes, Buenos Aires Province, Argentina) includes hundreds of mammalian fossil specimens collected from the Luján Formation (Lujanian Stage/Age), bounded to the Late Pleistocene/Early Holocene. Among the specimens of the MCA collection, a caudal vertebra (MCA-117) of Glyptodon sp. (Xenarthra, Cingulata) with pathologies was identified, which are here characterized in order to perform a diagnosis. The main alterations in the vertebra consist of bone erosion and remodeling in the left transverse process, bone erosion in the vertebral centrum, and deformation in the neural arch affecting the prezygapophyses. The features identified in the transverse process were diagnosed as bone remodeling, alterations previously described for Pleistocene xenarthrans. The erosions observed in the vertebral centrum are comparable to spondylosis, Schmorl's node, intervertebral discopathies, or, alternatively, calcium pyrophosphate deposition disease. Nonetheless, these could potentially manifest as secondary complications arising from spondylosis. Regarding characteristics such as low bone density, it is concluded that they are indicative of modifications due to osteoporosis. The alterations present in the specimen can be compared with bone pathologies recognized in elderly individuals with large body mass. • Pathology on the sixth caudal vertebra of Glyptodon. • It shows pathological traits likely linked to spondylosis and osteoporosis. • Bone pathologies present in elderly individuals with large body mass. • Caudal pathologies in glyptodonts need to be further studied. [ABSTRACT FROM AUTHOR]

Coprolites provide information about the presence, diet, and feeding behavior of the producer, besides the trophic relationships between extinct taxa and the regional paleoclimatic context where these organisms lived. Here, we present a paleobiological and paleoecological investigation of a Late Pleistocene carnivore coprolite found in southern Brazil (Touro Passo Formation, Rio Grande do Sul). Our analyses include morphological and morphometric approaches employing scanning electron microscopy, energy-dispersive X-ray spectroscopy, and CT-scanning. The analyzed coprolite is cylindrical, measuring 180 mm in length and 40 mm maximum in diameter, and contains a high proportion of phosphorus and calcium. Interestingly, it presents a large quantity of 102 osteoderms attributed to a Pleistocene ground sloth (Mylodontidae indet.). The size and contents of the coprolite suggest that it was produced by a large carnivorous animal comparable to representatives of Smilodon or another large carnivore mammal. The structure of the osteoderms resembles the morphological pattern found in Mylodontidae, but they are smaller than those described for adult individuals, suggesting that the coprolite producer possibly fed on a juvenile ground sloth. Palynological analysis was also performed, and the low pollen content indicates accidental consumption of plants or pollen, through the viscera of the prey or with the ingestion of water. These paleoenvironmental data suggest that the coprolite producer may have inhabited floodplain regions near river courses, where the coprolite was deposited. These results help to understand the ecological dynamics during the Late Pleistocene of South America. • A record of one of the few coprolites in South American Pleistocene. • Multi-proxy analysis indicate a large carnivore producer (e.g. Smilodon). • More than 102 Mylodontidae osteoderms preserved in the matrix. • The palynological analysis indicates dry and cold grassland environment. [ABSTRACT FROM AUTHOR]

Notiomastodon platensis was a Pleistocene proboscidean endemic to South America, and until now, the unique proboscidean taxon recognized in Brazil, representing one of the most important herbivorous megamammals present in the Brazilian Intertropical Region (BIR). The aim of this study was to analyze δ 13C and δ 18O isotopic signatures from samples from two dentin incremental layers of an individual tusk from the Sousa municipality (Paraíba State, Brazil), in order to infer diet, niche breadth, and paleoenvironment. Radiocarbon dating suggests that the studied individual lived in the Last Glacial Maximum age (24,190–24,567 Cal yr BP), and probably had a mixed-feeder diet with slightly higher consumption of C 3 plants (δ 13C = −7.5 ± 0.2‰, p i = 68%) during two years of its life. We suggest a generalist habit (B A = 0.83) for this individual, similar to the results found for this species in other BIR locations. In addition, we suggest that the individual from Sousa/PB lived in a wetter environment (δ 18O = 27.2 ± 0.5‰) when compared to other localities in the BIR. • A two years isotopic diet for a mastodont is presented; • This individual lived between 24,190–24,567 Cal yr BP; • The δ 13C indicate a mixed-feeder diet; • The δ 18O signature suggests a wetter moment in the region. [ABSTRACT FROM AUTHOR]

Abstract The study of two caves from the Serra do Ramalho region is here presented, this is one of the most important karstic areas in Brazil. A taxonomic analysis revealed 29 taxa including Xenarthra, Cetartiodactyla and Carnivora, ranging from Late Pleistocene to Early Holocene. Taphonomic studies reveal taphocoenosis consisting mainly of complete elements, without significant transportation, but also of transported elements, composing spatial-mixed, predominantly in situ-preserved assemblages. The predominance of Xenarthrans found within the caves is probably biased by a taphonomic pattern since these animals would have life habits related to cave environments, therefore with higher chances of preservation. There is evidence of accidental death of the scelidotheriines in Lapa dos Peixes cave, where entrapment of the animals during one or more events of river flooding is pointed as a hypothesis. Deposition took place within different periods of dry and humid climate incorporating bones in clastic and chemical deposits. Cycles of sedimentary deposition and reworking (erosion) may have acted in generating complex and overlapping depositional patterns with time averaging. During depositional phase, while the cave environment was occupied rather by Xenarthrans, parts of other animals were transported in the scope of fluvial systems and gravity loads, as well as by accidental falling or scavengers. The sedimentary deposits are currently being eroded by rain runoff in both caves, causing the reallocation of finer sediments to deeper conduits but the fossils keep close to their original location. This process is exposing a large amount of fossils, allowing extensive sampling which would be impossible with active excavations, since it would require an excessively longer time and damages to the caves. Highlights • Fossils naturally exposed by erosion were studied in two caves from Brazil. • 29 taxa, mostly Xenarthrans, were found with life habits related to caves. • Taphocoenosis mainly of complete elements, but also transported elements. • Dry and humid climates formed clastic and chemical deposits with time averaging. • Low energy erosive phase has transported fine sediments while keeping the fossils in place. [ABSTRACT FROM AUTHOR]

Bahia state is widely known for the presence of fossiliferous deposits of Late Pleistocene – early Holocene. Although most studies in the state have been carried out on cave environments, studies concerning natural tank deposits have been expanded in the last few years, particularly in other states of Northeast Brazil. Therefore, the present work aims to study two new natural tanks: “Lagoa das Abelhas” and “Lagoa do Rancho”, in Guanambi municipality, south-central Bahia, Brazil. The identified taxa include representatives of Xenarthra ( Eremotherium laurillardi , cf. Glossotherium sp., Pachyarmatherium brasiliense , Glyptodontinae, Propraopus sulcatus , Pampatherium humboldti , and Holmesina paulacoutoi ), Notoungulata (Toxodontidae), Proboscidea, Perissodactyla ( Tapirus terrestris and Equus ( Amerhippus ) neogaeus ), and Cetartiodactyla (Camelidae). The taphonomic analysis allowed the fossiliferous deposit from Lagoa das Abelhas to be classified as an ex situ assemblage, while the Lagoa do Rancho deposit was interpreted as a peripheral assemblage. Based on its paleofaunal composition, the landscape of the Guanambi region would have comprised open areas with pastures and patches with arboreal elements. The 14 C radiocarbon dating results point to ages of 22,230 ± 55 years for the Lagoa das Abelhas and 16,020 ± 40 years for the Lagoa do Rancho tanks, indicating that the Guanambi paleofauna lived during the Last Glacial Maximum, in a drier phase of the Late Pleistocene. [ABSTRACT FROM AUTHOR]

Tank deposits are an exceptional type of fossiliferous deposit and bear a remarkably fossil record of the Pleistocene megafauna of South America, particularly of Brazil. The taphonomy of vertebrate remains preserved in this type of environmental context was clearly driven by climate, similarly to most of the Quaternary continental fossil record. The formation of the vertebrates fossil record in tank deposits was influenced by the climate seasonality typical of arid climate. The taphonomic history of most tank deposits is a consequence of this seasonality and, as a result, the paleoecological data preserved in their fossil assemblages is reliable with respect to paleobiological and paleoenvironmental settings of the Quaternary ecosystems of the Brazilian Intertropical Region (BIR). Other tank deposits experienced an unusual taphonomic history that, besides climate, was affected by recurrent events of reworking produced by the depositional agents dominant in the surrounding alluvial plains. The conclusions obtained here concerning the main taphonomic settings and formative processes that characterize fossil vertebrate assemblages of tank deposits will help further studies aimed to recover information on the paleoecology of Quaternary fauna collected in such deposits by allowing a better understanding of their time and spatial resolutions and other potential biases. [ABSTRACT FROM AUTHOR]

The Picos II Paleontological Site (PIIPS), located in the city of Piranhas, in Alagoas State, is a fossil deposit with a pond-like geomorphological feature, a kind of peculiar deposit for the Quaternary of Northeast Brazil. A detailed taphonomic study is presented about the PIIPS assemblage, from material collection to the laboratory analysis. The conservation state of the collected fossils in PIIPS is different from that found in other tank deposits, showing a high degree of specimen preservation. Two taxa of pleistocenic mammals have been identified: Eremotherium laurillardi and Notiomastodon platensis , and fragments of an avian bone, whose taxonomic identification was not possible. The taphonomic analysis indicates that the deposited material experienced a short transportation in high-energy event, with a short period of subaerial exposure before the final burial, where at least the final disarticulation occurred in situ , which explains the high conservation level of the material. The sedimentological analysis made in each layer of the deposit corroborates the information related to the transport of the material, which were obtained in taphonomic analysis. Regarding these aspects, PIIPS reflects nearly non-biased biocenotic patterns. The well-preserved material found in PIIPS demonstrates the great potential of deposits with pond-like geomorphological features, with sidelines that are less steep than traditional tanks, providing smoother transport and accommodation for skeletal elements, which is a distinguishing factor in preserving fossils of vertebrates. [ABSTRACT FROM AUTHOR]

Tanks are natural, mostly elliptic depressions formed in the igneous or metamorphic basements of northeastern Brazil. The taphonomy of the fossil vertebrate assemblages preserved in tank deposits has been intensely studied. However, so far the focus was mainly on biostratinomic aspects. This paper presents a diagenetic analysis of megafauna bone thin sections from four tank deposits in northeastern Brazil, the interpretation of their diagenetic histories and a comparison between the sites. The geographic proximity of the sites and their similar paleoclimatic settings were the likely factors responsible for the similarities observed among the thin sections of different tank deposits. In contrast, some striking differences resulted from the particular characteristics of the areas in which the tank deposits are located, most notably the local geological settings and their distances from nearby drainages. Comparisons with other studies showed that the availability of water and conditions that favored permineralization were common in northeastern Brazil during the Quaternary. Finally, diagenetic contrasts among bones thin sections from the same tank evidence temporal mixing in the vertebrate accumulations within these natural-trap deposits. • Tank deposits in Northeastern Brazil experienced similar diagenetic histories. • The chemistry of surface waters strongly influenced the fossildiagenesis. • A possible paleocurrent was proposed for the Riacho Verde Tank. • Comparisons indicate permineralization as a favored process during the Quaternary. [ABSTRACT FROM AUTHOR]

This paper provides diet interpretations for nine giant ground sloth species that lived in the Brazilian Intertropical Region, through the relative muzzle width technique and occlusal surface area (except Mylodonopsis ibseni). We propose that Eremotherium laurillardi , Ocnotherium giganteum , Mylodonopsis ibseni , Glossotherium phoenesis , Catonyx cuvieri , Valgipes bucklandi , Ahytherium aureum , and Australonyx aquae were adapted to had a mixed-feeder diet, having a great oral food processing, which could indicate an adaptation to need less from the fermentation on digestive tract, and similar, or even higher, metabolic requirements in comparison with ungulates of similar body mass. While, N. maquinense was adapted to a browser diet, and probably presented high fermetantion capability and low metabolic requirement, in comparison with all other giant ground sloth taxa. • The diet of nine extinct giant ground sloths from BIR is presented. • Eight taxa were mixed-feeder, with great oral food capacity. • Eight taxa had high metabolic requirements. • Nothrotherium was browser, with low oral food capacity. • Nothrotherium had low metabolic requirements. [ABSTRACT FROM AUTHOR]

Abstract: Quebrada (stream) Ñuagapua, which is located in the Bolivian Chaco in the Andean foothill generates an alluvial fan many kilometres in length. Three major lithostratigraphic units characterise the sedimentary sequence in this region. The lower and upper parts are formed from predominantly sandy sediments that demonstrate rapid growth of the alluvial fan, associated with an intense erosion of barren slopes. The intermediate unit consists of forest soil that seals deep channels containing bones together with a forest association. The remains of a wooden plank, dated 140 yr BP, were found at the top of this soil, which laterally contains charcoals, ash layers and large charred trunks, sometimes in growth positions. Roots localised in this layer also sustain a number of very large still living trees. These findings are evidence of a recent phase of alluvial fan sedimentation resulting from slope erosion activated by forest clearing. The Chaco has been intensively settled for agricultural and pastoral purposes since the 18th century. The lower unit contains a hearth, scattered burnt bones, flint flakes and ceramic artefacts. Radiometric dating indicates a middle Holocene human occupation, between ca. 7.79 and 6.65 ka cal yr BP. We suggest that the sedimentary unit is associated with intense soil erosion processes triggered by early Neolithic deforestation. A sandy layer of the lower unit, slightly above the archaeological remains, contains transported bones of megafaunal elements that apparently represent the South American latest occurrence of some extinct taxa. The mammal association is highly heterogeneous, containing species living in aquatic, forest, prairie and savannah environments from a very specific layer that represents the almost simultaneous burial of animals killed slightly up-valley. This anomalous association is probably the result of human impact as opening the forest favoured the introduction of open environment fauna that had previously survived on the southernmost part of the continent. Therefore, humans may have played a role in mammalian extinctions in this region, either directly, due to hunting, or due to changing the paleoenvironmental conditions on a wider scale. [Copyright &y& Elsevier]

Abstract: Fossils of terrestrial mammals preserved in submarine environment have been recorded in several places around the world. In Brazil such fossils are rather abundant in the southernmost portion of the coast, associated to fossiliferous concentrations at depths up to 10 m. Here is presented a review of such occurrences and the first record of fossils in deeper areas of the continental shelf. The fossils encompass several groups of both extinct and extant mammals, and exhibit several distinct taphonomic features, related to the marine environment. Those from the inner continental shelf are removed and transported from the submarine deposits to the coast during storm events, thus forming large konzentrat-lagerstätte on the beach, called “Concheiros”. The only fossils from deeper zones of the shelf known so far are a portion of a skull, a left humerus and of a femur of Toxodon sp. and a lower right molar of a Stegomastodon waringi, all collected by fishermen at depths around 20 m. The presence of fossils at great depths and distances from the present coastline, without signs of abrasion and far from areas of fluvial discharges does indicate that these remains have not been transported from the continent to the shelf, but have been preserved directly on the area that today correspond to the continental shelf. These remains indicate the existence of large fossiliferous deposits that have developed during periods of sea-level lowstand (glacial maxima) and have been submerged and reworked by the sea-level rise at the end of the last glaciation. [ABSTRACT FROM AUTHOR]

Although the extinct Quaternary megafauna is widely recorded in northeastern Brazil, geochronological studies carried out on its fossiliferous deposits are still scarce. In this study, Electron Spin Resonance (ESR) was applied to date 12 tooth fragments of Toxodon platensis (Mammalia, Notoungulata) collected in the tank deposit of Lago do Rumo, Baixa Grande, state of Bahia, Brazil. The results obtained in the geochronological analysis performed here reveal ages from around 60 ka to 34 ka for T. platensis in Lagoa do Rumo; and, considering the integration data in the paleontological literature, our results evidence the largest time-averaging ever recorded for tank deposits: around 51 thousand years. • Twelve teeth of Toxodon platensis from Brazilian Northeast were dated using Electron Spin Resonance. • Absolute dating revealed fossils of Toxodon platensis ranging from around 60 ky to 34 ky. • Considering the literature, time-averaging in Lagoa do Rumo is around 51 thousand years. [ABSTRACT FROM AUTHOR]

In the late Pleistocene of two localities of Brazilian Intertropical Region (one in Bahia state, and another in Piauí state) lived meso-megamammals herbivores belonging, at least, to three guilds: mixed-feeders (Eremotherium laurillardi , indetermined Equidae, Glyptotherium sp., and Holmesina paulacoutoi), grazers (Notiomastodon platensis , Glyptotherium sp., indetermined Cervidae, and Toxodon platensis) and omnivores (Pachyarmatherium brasiliense). The paleoecologial informations (datings, isotopic diet and niche breadth) were acquired through radiocarbon datings and ratio isotopic analysis of carbon (δ 13C). The Notiomastodon platensis from Caetanos, Bahia presents a radiocarbon dating of 23,040 ± 55 14C years BP (25,604–25,203 Cal years BP) showing that it lived in the region in the late Pleistocene. We propose that Notiomastodon platensis (p i > 74%) and Glyptotherium sp. (p i > 76%) had preference for C 4 plants, Equidae preferred to eat C 3 plants (p i = 62%), while Cervidae and Toxodon platensis were specialists in C 4 plants (p i = 100%). Eremotherium laurillardi had a genaralist diet, with preference for C 3 plants in Piauí (p i = 66%), and in C 4 plants in Bahia (p i = 68%). Holmesina paulacoutoi had a generalist diet, as well, prefering C 4 plants (p i = 59%). Pachyarmatherium brasiliense was the unique omnivore in this study, and could explore savanna habitats, searching for food. The δ 13O values in Caetanos, Bahia ranged from 27.2% to 29.5% and for São Raimundo Nonato, Piauí, from 29.5% to 32.7%. We suggest that the paleoenvironments in both localities was constitude by dry and open environments. • New carbon and oxygen isotopic data for the Brazilian megafauna is presented. • A new radiocarbon dating is presented for Notiomastodon platensis from Bahia, Brazil. • A paleoenvironment proposal were made for two localities in northeastern Brazil. [ABSTRACT FROM AUTHOR]

The Amazon region is a key area to understand the South America history, displaying a significant importance in the study of Pleistocene mammal fossils. Here, we present the taxonomic account of the first megafaunal records of the Quaternary deposits from bed and alluvial terraces from the Teles Pires River and its tributaries, in northern Mato Grosso state, southern Brazilian Amazon. Teeth, partial dentaries and postcranial fossil specimens have been described and identified as immature to senile individuals of Notiomastodon platensis , cf. Eremotherium and Toxodon platensis. These species were well-dispersed along the Pleistocene in South America, including the Amazon region. This paper brings up the paleontological potential of the upper Teles Pires basin, midwest Brazil, for South American Pleistocene megafauna. Further studies are necessary in order to obtain more information regarding the location and genesis of the fossiliferous assemblages, and the paleoecological and taphonomic aspects of the megamammal paleocommunities in the southern Amazon. • Pleistocene megamammal fossils from a new locality in Brazilian Amazon were identified and described. • Teeth, dentaries and postcranial specimens were attributed to Notiomastodon platensis , cf. Eremotherium and Toxodon platensis. • The individual specimens belonged from immature to senile adult age classes. • The upper Teles Pires basin in Mato Grosso state, Brazil, has a great paleontological potential for megafaunal fossils. [ABSTRACT FROM AUTHOR]

During the Pleistocene, a diverse fauna composed of large and mega mammals lived in the Northeastern of Brazil, and is generally associated with open environments. We present in this study carbon and oxygen isotopic data of Notiomastodon platensis and Toxodontinae from the fossiliferous deposit of Lajedão do Patrício, João Dourado, Bahia, Brazil. The analyzes of δ 13C and δ 18O were carried out to better understand the paleoecology of these taxa and, consequently, make it possible to obtain paleoclimatic and paleoenvironmental inferences about the region of Lajedão do Patrício fossiliferous deposit. The δ 13C values identified for Notiomastodon platensis (−5.67‰ and −6.95‰) and Toxodontinae (−5.62‰ and −7.03‰) indicate a mixed diet for these taxa due to the consumption of C 3 and C 4 plants, indicating an environmental scenario of vegetation mosaic of dry forest (caatinga) and cerrado during the Pleistocene/Holocene. The comparison between the δ 13C data from the megafauna in Northeast Brazil allowed the identification of opportunistic behaviors for Notiomastodon platensis and Toxodontinae, varying between the browser, mixed and grazing habits, according to the characteristics of the habitat in which they lived. The δ 18O data and its variations suggest changes in the precipitation regime during the Pleistocene/Holocene transition in the region of the analyzed fossiliferous deposit. • Analysis of stable isotopes (carbon and oxygen) in fossil teeth of the Quaternary megafauna in northeastern Brazil. • Paleoenvironmental scenario of vegetation mosaic with dry forest and grass vegetation. • Comparison of date isotopic and paleoclimatic curves indicates different climatic and environmental conditions. [ABSTRACT FROM AUTHOR]

We conducted a paleopathological study in 230 fossil specimens that were collected and prepared by Ney Vidal (renowned Brazilian paleontologist) during the 1940s and 50s. These fossils were housed at the Collection of Vertebrate Paleontology of Museu Nacional of the Universidade Federal do Rio de Janeiro (MN/UFRJ), which were tragically lost in the fire that destroyed the Museu Nacional on September 2nd, 2018. Four isolated specimens assigned to Eremotherium laurillardi exhibited pathological alterations (1.9%), diagnosed as spondyloarthropathy (inflammatory arthritis) and linear defect (a type of vertebral endplate defect). Spondyloarthropathy has been often diagnosed in Late Pleistocene glyptodonts and giant ground sloths, but this is the first report of linear defect for any species of Xenarthra. • New case of spondyloarthropathy in a representative of Pleistocene Megafauna of Brazil. • First record of a linear defect in Xenarthra. • Eremotherium laurillardi was the species with the greater number of bone diseases in tank deposits. [ABSTRACT FROM AUTHOR]

This paper presents the results of multidisciplinary research in the Ecuadorian coastal regions, with particular emphasis on the Santa Elena Peninsula. The new evidence, together with previous data gathered on the Ecuadorian cordillera during the last 12 years, allows us to formulate a model that accounts for most of the mammal megafauna extinction at the Pleistocene/Holocene transition. After the illustration of geomorphological and paleontological evidences of the area of the Santa Elena Peninsula (and other sites), and of a summary of the paleoclimatic data, the main results and conclusions of this work are: (1) Late Pleistocene mammal assemblages survived in the Ecuadorian coast until the Early Holocene sea level rise; (2) Prior to the extinction of most of the megafauna elements (mastodons, ground sloths, equids, sabre-tooth felids), the mammal communities at Santa Elena Peninsula comprise elements with differing habitat requirements, attesting conditions of high biological pressure; (3) At the El Cautivo site (Santa Elena Peninsula), we have discovered Holocene sediments containing the first known occurrences in Ecuador of lithic artifacts that are associated with mammal megafauna remains; (4) During the last 10,000 years, the coastal region of Ecuador underwent significant changes in vegetation cover. At the Pleistocene/Holocene transition the climate changed from very arid conditions to humid conditions.Our data indicates that the megafauna definitively abandoned the Cordillera areas around 12,000 yr bp due to t he increasing aridity, and subsequently migrated to coastal areas where ecological conditions still were suitable, Santa Elena Peninsula and mainly Amazonian areas being typical. We conclude that the unusual high faunal concentrations and the change to dense vegetation cover (due to a rapid increase in precipitation in the lower Holocene) at 8000–6000 yr bp, caused the final collapse and extinction of most elements of the mammal megafauna. Vegetation cover in the area of Santa Elena should have been extensive, and even more so in the Guayas and Guayabamba valleys. The newly densely vegetated areas, and fluvial barriers, transformed the refugia into lethal traps for large animals already under biological stress, such as were mastodons, ground sloths and equids. Within the megafauna, only tapirs and artiodactyla (Cervidae and Camelidae) survived.In our opinion, the most suitable model to justify the great crisis of the mammal megafauna at the Pleistocene/Holocene transition, also in areas out of Ecuador, must be mainly based on the three parameters: high aridity, high humidity and geographic factors. [Copyright &y& Elsevier]

The tragic fire at the National Museum (Brazil) in September 2018 caused invaluable losses to South American natural and cultural heritage. However, previous visits to the paleontological collection generated photographic and descriptive records of mammalian fossil specimens from the Pleistocene of Brazil. Thus, it was possible to redescribe and revise the taxonomy of Cervidae fossils from two important paleontological sites in the Brazilian Intertropical Region (João Cativo and Lage Grande). These fossils include antlers and lower teeth, and they were described and taxonomically identified by morphological comparisons with all extant and extinct South American deers. A new diversity of Cervidae was recognized, differently from that proposed in the literature, which recognized the presence of Hippocamelus sulcatus , Mazama americana , and Ozotoceros bezoarticus. Instead, the Cervidae fossils from João Cativo and Lage Grande sites belong to the extinct deer Morenelaphus. Although some specimens could not be identified at a specific level (Cervidae indet.), a comparative analysis of the estimated body mass pointed out the most massive deer in South America (including extinct and extant) and recognized Morenelaphus as the second heaviest. The record of these large deers with huge antlers suggests the presence of natural grasslands areas and milder climatic conditions for late Pleistocene in the Brazilian Intertropical Region. Climatic and environmental changes may have driven these large deers to extinction in the Pleistocene/Holocene transition. This study reveals an unprecedented Cervidae diversity for the Brazilian Intertropical Region, emphasizes the relevance of dental features, together with antlers morphology, in taxonomic studies of Cervidae, and also highlights the importance of South American natural heritage in the retrieving of knowledge and new scientific discoveries through collection specimens. • Dental features are as significant as antlers morphology in Cervidae taxonomy. • South American low latitudes are here included in the geographic distribution of Morenelaphus during the Pleistocene. • We noticed the greatest and heaviest Cervidae ever recorded in South America. • The presence of giant deers suggests grasslands and milder climate to Brazilian Intertropical Region during the Pleistocene. • Pleistocene changes in climatic/environmental possibly influenced the extinction of giant deers. [ABSTRACT FROM AUTHOR]

The knowledge on the Pleistocene biota that inhabited the Brazilian midwestern region is scarce and no data on the paleoecology of Eremotherium laurillardi from this region have been published so far. The main objective of this study is to provide information about the age and feeding ecology of that taxon from Goiás state and to compare the results with other localities from the Brazilian Intertropical Region (BIR). Carbon isotope and stereomicrowear analyses were performed in a molariform from the left maxilla found in Piranhas municipality. The results include a14C AMS dating of 32,390 ± 100 (34,705-33,947 cal yr BP), and a δ13C value of −8.99‰, which indicates a generalist diet (B A = 0.96) with similar proportions of C 3 (p i = 57%) and C 4 (p i = 43%) plants consumed. The stereomicrowear results also suggests a mixed diet, although the high values of scratches could be associated to the significant consumption of grasses. Coarse features on the orthodentine surface indicate possible ingestion of exogenous grit due to the behavior of foraging close to or at the ground. The generalist behavior corroborates previous studies from other localities of the BIR. E. laurillardi from midwestern Brazil possibly consumed higher proportions of shrub/tree foliage, whilst in northeastern Brazil it probably had a dominant diet of C 4 herbaceous plants. The distinct feeding behavior is a consequence of different climatic and environmental conditions between these regions during late Pleistocene. Our integrative study was efficient to improve the understanding about the paleoecology of this emblematic ground sloth that inhabited midwest region of the BIR during the late Pleistocene, but additional work is needed for more detailed interpretations. • The age assigned to the material was 32,390 ± 100 (34,705-33,947 cal yr BP). • The sample is the oldest 14C AMS dating reported for this taxon in the BIR. • The individual was a generalist (B A = 0.96) mixed feeder (p i C 3 = 57%; p i C 4 = 43%). • Comparative stereoscopic microwear also indicates a mixed diet for the individual. [ABSTRACT FROM AUTHOR]

We applied the ESR (Electron Spin Resonance) dating method to fossils of Notiomastodon platensis (two teeth) and Toxodontinae (two teeth) found in the fossiliferous deposit of Lajedão do Patrício, João Dourado, State of Bahia, Brazil, to identify the period of formation of this fossil accumulation. Neutron Activation Analysis was applied to determine the concentrations of the main radioisotopes in enamel, dentine and sediment. The ages found for N. platensis are 16.8 ± 2.6 ka and 12.5 ± 2.3 ka, while the ages for Toxodontinae are 9.6 ± 1 ka and 9.1 ± 1 ka. The results for Notiomastodon. platensis and Toxodontinae are similar to other fossiliferous of Brazil. The estimated maximum time-averaging for Lajedão do Patrício is 11.3 ka, indicating a long period of accumulation of skeletal remains, attributed to resedimentation and reworking. The crossing between the period of formation of fossil assemblage Lajedão do Patrício and ages of climatic variations diponible in paleoclimatic curves produced for the Quaternary of northeastern Brazil indicates different climatic and environmental conditions during the formation of the deposit. • Dating Electron Spin Resonance (ESR) Notiomastodon platensis and Toxodontiane from the Quaternary of Northeast Brazil. • Notiomastodon platensis are 16.8 ± 2.6 ka and 12.5 ± 2.3 ka, and Toxodontinae 9.6 ± 1 ka and 9.1 ± 1 ka. • Maximum time-averaging for Lajedão do Patrício is 11.3 ka, indicating a long period of accumulation. • Comparison of Lajedão do Patrício and paleoclimatic curves different climatic and environmental conditions. [ABSTRACT FROM AUTHOR]

The fossil mammals that lived in the Brazilian Intertropical Region during the Quaternary are found in different types of deposits (e.g. natural tanks, ponds, caves, rockshelter, and riverbeds) throughout the Brazilian territory. The state of Bahia, located on northeastern Brazil, stands out for the presence of large and important caves, which are characterized by the natural deposition of sediments and fossils. The study aims to identify the fauna found in the Borboletas Cave, and to provide the first paleoecological inferences for the environment during the Late Pleistocene-Holocene. Here we present the first record of Palaeolama major, Hippidion principale and Smilodon populator in Paripiranga, Bahia. Coendou sp., Mazama gouazoubira , and Toxodon platensis , already known to the region, were also collected and identified. Based on the chronological and geographical distribution of the taxa, it is suggested that the faunal content found lived during the Late Pleistocene – Holocene. The presence of the taxa found indicate an open paleoenvironment, similar to savanna, with areas covered with grasses associated with areas with forest cover. This study demonstrates that the Borboletas Cave is the richest paleontological site carrying the mammals in this region. • First paleoenvironmental reconstitution for northeastern Bahia, Brazil. • Solid description of fossils in Borboletas Cave. • Rich and most diversified natural assemblage of paleomastofauna. • Amplification of the paleobiogeography of extincted taxons. [ABSTRACT FROM AUTHOR]

The fossils of Pleistocene megafauna are commonly found in tanks and cave deposits in the State of Bahia, northeastern Brazil. In general, studies on these materials have focused mainly on taxonomic aspects, but more recently, there has been an increase in paleoecological studies based on stable isotopes. The present paper describes fossils recovered from a tank deposit in Lagoa de Pedra (Anagé municipality, Bahia State). The material was identified as: Eremotherium laurillardi , Panochthus sp., Holmesina paulacoutoi , Palaeolama major , Notiomastodon platensis , and Toxodontinae indet. Stable isotope analyses were performed in order to estimate their diet and the paleoenvironment in which these taxa lived. The results indicate the occurrence of two guilds: grazers (Panochthus sp.) and mixed-feeders (H. paulacoutoi , N. platensis and E. laurillardi). These animals lived in a more open environment where N. platensis possibly had a major role in the community organization. • New fossil locality with Late Pleistocene megamammals remains in Bahia, Brazil. • Unpublished isotopic data for Pleistocenic herbivores mammals from Bahia, Brazil. • Paleoenvironmental reconstruction for Anagé region. [ABSTRACT FROM AUTHOR]