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Isotopic paleoecology (δ13C, δ18O) of Late Quaternary megafauna from Mato Grosso do Sul and Bahia States, Brazil
Abstract
In the present study, the paleoecology (diet and niche width) of Late Quaternary megamammals that inhabited the Brazilian Intertropical Region (BIR) was assessed at two sites in the states of Bahia and Mato Grosso do Sul. The δ13C analyses suggest a generalist diet for Notiomastodon platensis, Palaeolama major, Holmesina paulacoutoi and Glyptotherium sp., while Equus neogeus was a grazer with a diet consisting exclusively of C4 grasses, and Eremotherium laurillard, a predominant browser with a diet consisting predominantly of C3 plants. A distinct diet pattern was inferred for one species: Toxodon platensis with a mixed-diet preferring C4 grasses in Mato Grosso do Sul but predominantly the C3 feeder in Bahia. These results show a high ecological plasticity of this species and may suggest distinct ecological pressures or different vegetation configurations in the two regions. Diet reconstitutions based on δ13C analyses suggest that an open savanna-like landscape predominated in both areas. The δ18O values reveal that Mato Grosso do Sul could have experienced wetter climatic conditions than Bahia during the Late Quaternary, suggesting a humid corridor in midwestern Brazil, or that there were different contents of δ18O of water sources between these areas. Hence, we assume that the same faunistic composition in different geographical areas is not enough to delimit the ecosystems of the BIR, and we recommend that the definitions of BIR should be revised to include more refined paleoclimate data. Other studies around the world should consider the same for delimitations of zoogeographic regions.
... Concerning this, dental evidence (i.e., hypsodontia, which has traditionally been related to grazing habits in open grasslands, and tooth enamel microstructures that demonstrate increased resistance) suggests consumption of abrasive vegetation (Bond et al., 1995;Townsend & Croft, 2008;Cassini et al., 2011;Braunn et al., 2021); although some authors proposed that hypsodonty is not always associated with a grazing habit (e.g., Feranec, 2003;DeMiguel et al., 2008DeMiguel et al., , 2015Townsend & Croft, 2008). In recent decades, isotopic studies focused on the late Cenozoic fauna of South America have become increasingly frequent (e.g., Domingo et al., 2012Domingo et al., , 2020Dantas et al., 2013Dantas et al., , 2020Dantas et al., , 2022Bocherens et al., 2016;Pansani et al., 2019;Sanz-Pérez et al., 2022, 2024Varela et al., 2023), although still, many questions remain. In this context, the number of works that include representatives of Toxodontidae is low, and most of them are limited to the Pleistocene genus Toxodon (e.g., Lopes et al., 2013;da Silva et al., 2019;Pansani et al., 2019;Gomes et al., 2023;Varela et al., 2023). ...
... In recent decades, isotopic studies focused on the late Cenozoic fauna of South America have become increasingly frequent (e.g., Domingo et al., 2012Domingo et al., , 2020Dantas et al., 2013Dantas et al., , 2020Dantas et al., , 2022Bocherens et al., 2016;Pansani et al., 2019;Sanz-Pérez et al., 2022, 2024Varela et al., 2023), although still, many questions remain. In this context, the number of works that include representatives of Toxodontidae is low, and most of them are limited to the Pleistocene genus Toxodon (e.g., Lopes et al., 2013;da Silva et al., 2019;Pansani et al., 2019;Gomes et al., 2023;Varela et al., 2023). It is particularly interesting the study of MacFadden (2005), who analyzed the ecology of Pleistocene Toxodon and Mixotoxodon by comparing values from different regions of South America. ...
... It is particularly interesting the study of MacFadden (2005), who analyzed the ecology of Pleistocene Toxodon and Mixotoxodon by comparing values from different regions of South America. These studies point to a dietary plasticity of these genera, consuming both C 3 and C 4 plants depending on availability, for which they were traditionally considered as generalists (Defler, 2018;Pansani et al., 2019;Dantas et al., 2020). Additionally, Croft et al. (2020) highlighted that sometimes dietary interpretations derived from microwear analysis and morphological analyses do not agree. ...
Toxodontidae was an extinct family of South American notoungulates, widely studied systematically, but not so much from an ecological perspective. This work aims to improve the knowledge about variations in diet and habitats of different representatives of this group in the context of biotic and abiotic events throughout the last 20 My. The tooth enamel carbon isotope composition (δ 13 C) of 7 genera recorded in 11 localities of Central, West and Northeastern Argentina, from the Early Miocene to the Late Pleistocene, was analyzed. The diet of the toxodontids studied in this work range from mainly C 3 resources during the Miocene, mixed C 3 -C 4 in the Pliocene, to a significant consumption of C 4 plants during the Pleistocene. Differences in diet during the Late Pleistocene were also recorded, associated with geographic ( i.e ., Northeastern vs . Central) and temporal ( i.e ., glacial vs . interglacial periods) variations, evidencing the adaptive capacity of the group under ecological and environmental pressures.
... The teeth of xenarthrans are formed mostly of dentine, regarded as more prone to diagenetic modification compared to enamel because of its higher organic content, lower hardness, and smaller crystallites , thus making enamel the preferred material for isotope analysis. Nevertheless, isotopic studies on teeth of extinct sloths have been performed, showing that such analysis is feasible on dentin as well (Kohn et al., 2005;Ruez, 2005;Domingo et al., 2012;França et al., 2014;Silva, 2015;Dantas et al., 2017;Larmon et al., 2019;Pansani et al., 2019;Oliveira et al., 2020;Tomassini et al., 2020). The teeth of megatheriid sloths are prismatic, hypsodont, with subrectangular to subtriangular transverse outline and bilobate occlusal surfaces formed by transversal sharp crests separated by a deep valley (Owen, 1861;Spillmann, 1948;Sicher, 1953;Cartelle & De Iuliis, 1995;Vizcaíno, 2009). ...
... The δ 13 C value of this individual is similar to specimens from the Amazon and central-western Brazil (Pansani et al., 2019;Oliveira et al., 2020;Asevedo et al., 2021), and intermediate between closed canopy forest and forest gaps/ open woodland (Secord et al., 2008), thus it suggests foraging in riparian forests and neighboring open woodlands and grasslands, similar to the habit inferred for Megalonyx sloths from New Mexico (McDonald & Morgan, 2011). According to Oliveira et al. (2002), riparian forests were present along Pessegueiro Creek based on the type of vegetal remains (tree trunks and leaves) associated with the sloth fossils found in the channel deposits. ...
... Despite some anatomical differences in skull and jaw bones, both species share morphological features of browsers (narrow muzzle) and grazers (hypsodont teeth, Figure 6. A, distribution of fossils of Megatherium americanum and Eremotherium laurillardi with associated isotopic data found across South America; records of Eremotherium without isotopic data are also shown (from Paula Couto, 1979;Cartelle & De Iuliis, 1995;Rossetti et al., 2004;Praderio et al., 2005;Martinelli et al., 2012;Bocherens et al., 2017;Lopes & Pereira, 2019;Pansani et al., 2019;Domingo et al., 2020;Oliveira et al., 2020;Tomassini et al., 2020;Asevedo et al., 2021). B, Comparative δ 13 C data of both megatheriids across the continent. ...
The Pampa in subtropical Brazil (State of Rio Grande do Sul) is the only area of South America known so far where fossils of the Pleistocene giant megatheriid sloths Megatherium americanum, characteristic of subtropical-temperate areas, and Eremotherium laurillardi, widespread in the tropical zone, were discovered in the same deposits (Pessegueiro Creek and Chuí Creek), but it is not clear whether this co-occurrence is a product of taphonomic mixture, or co-existence, which would imply niche partitioning. In order to understand their paleoecology and reconstruct the associated paleoenvironments, dentin samples of both megatheriids from the two sites were analyzed for their carbon (δ13C) and oxygen (δ18O) isotope ratios. The δ13C values of Megatherium indicate mixed diet of C3-C4 plants with higher content of the latter in Pessegueiro Creek, whereas the δ13C values of Eremotherium indicate C3-dominated diets, the more negative value in Pessegueiro Creek possibly related to the canopy effect. The δ18O of Eremotherium points to 18O-depleted water sources, possibly also influenced by the diet, whereas Megatherium ingested 18O-enriched water. The results show that co-existence of both megatheriids would have been ecologically possible, and that the Pampa was occupied by open grasslands/woodlands, with closed forests in Pessegueiro Creek. The δ13C of Eremotherium from intertropical Brazil indicate a more generalist habit than Megatherium from subtropical Brazil and Argentina, which probably facilitated its dispersion from the tropics up to subtropical areas along two different routes, one along the coastal plain, and the other along the Paraná River Basin across central South America, following the southward expansion of riparian forests during warmer stages. The reduction of those forests during intervening cold stages possibly led to its disappearance in southern Brazil. Keywords: Quaternary, paleobiogeography, stable isotopes, Pampa, coastal plain, megafauna.
... Marcolino, 2012;Asevedo et al., 2012;. Nevertheless, increasing number of studies are employing isotopic analysis of fossilized mammalian mineralized tissues, proving to be an excellent tool (e.g., S anchez et al., 2004;Macfadden, 2005;Domingo et al., 2012;Lopes et al., 2013;França et al., 2014;Dantas et al., 2013;Pansani et al., 2019). ...
... Diet followed habitat phytophysiognomy, and it consisted predominantly of herbaceous plants, foliar and floral branches, fruits and woody parts Moth e et al., 2017). According to the carbon isotopes data, this proboscidean could have been a specialist C 3 browser in forest habitats of southwestern Amazon (md 13 C¼ e15.39 ± 1.63‰; median¼ 15.61; IQR¼ 2.21; Fig. 4B), but was a browser or mixed feeder in C 3 woodlands/grasslands from Pampean regions of Argentina, Uruguay and Brazil (md 13 C¼ e8.2 ± 2.1‰; median¼ 8.26; IQR¼ 1.4; Fig. 4B ;S anchez et al., 2004;Guti errez et al., 2005;Domingo et al., 2012;Lopes et al., 2013), a dominant grazing diet in C 4 grasslands in the Brazilian Intertropical Region (BIR; md 13 C¼ e1.08 ± 2.66‰; S anchez et al., 2004;Viana et al., 2011;Dantas et al., 2013;França et al., 2014;Dantas et al., 2017;Pansani et al., 2019), and a mixed feeding diet in C 3 -C 4 woodland/ grassland landscapes in Andean regions of Ecuador and Peru (md 13 C¼ e4.7 ± 3.11‰; median¼ 5.72; IQR¼ 6.45; Fig. 4B Fig. 4B; Alberdi et al., 2008;Domingo et al., 2012). With a Pan-American distribution covering the southeastern North America to southern Brazil, the ground sloth E. laurillardi has also been estimated as a generalist species (Dantas et al., 2017). ...
... With a Pan-American distribution covering the southeastern North America to southern Brazil, the ground sloth E. laurillardi has also been estimated as a generalist species (Dantas et al., 2017). The carbon isotope analysis in specimens of the BIR demonstrated a large range that covers pure C 3 (browser), mixed feeders and pure C 4 (grazer) consumers (md 13 C¼ e5.4 ± 3.92‰; median¼ 5.11; IQR¼ 4.54; Fig. 4A; Viana et al., 2011;Dantas et al., 2013Dantas et al., , 2014França et al., 2014;Dantas et al., 2017;Pansani et al., 2019), differing from our results for an exclusive C 3 browser pattern in the Brazilian Amazon (md 13 C¼ e15.92 ± 1.38‰; median¼ 16.14; IQR¼ 2.60; Fig. 4A). ...
We report the first radiocarbon datings and carbon (d 13 C) and oxygen (d 18 O) stable isotopes data to reconstruct the paleoecology of medium to large herbivorous mammals from late Quaternary of southwestern Amazon (Acre and Rondônia states, Brazil). AMS 14 C dates for Neochoerus sp. (29,072-27,713 Cal yr BP), Notiomastodon platensis (25,454-24,884 Cal yr BP) and Eremotherium laurillardi (11,320-11,131 Cal yr BP) support the Lujanian ages. All fossils have low d 13 C and d 18 O isotopic values that suggest C 3-dominated environments from closed canopy forests to wooded savannas, agreeing with paleovegetation reconstitution. Most species were browsers (piC 3 ¼100%; Niche breadth, B A ¼0), where the key species with the largest body mass, N. platensis (~6,300 kg) and E. laurillardi (~3,500 kg), possibly had a more generalized browser diet in closed-canopies to woodlands. Their diet distinguished from the C 3 /C 4 generalist Trigodonops lopesi (~1,900 kg), which foraged in wooded savannas (p i C 3 ¼70%; B A ¼0.72), similarly with its relative Toxodon platensis (~1,800 kg) that had a browse-dominated mixed feeder diet (p i C 3 ! 84%, B A 0.38) in Peruvian and Bolivian Amazon localities. Palaeolama major (~280 kg) was possibly a strictly folivorous within forest canopies, whereas Tapirus sp. (~250 kg) and Mazama sp. (~40 kg) were browsers in closed-canopies to woodlands. Holmesina rondoniensis (~120 kg) was a browser but not restricted, where could also feed on herbaceous from understories in woodlands, and Neochoerus sp. (~200 kg) feeding predominantly herbaceous plants in wooded savannas (piC 3 ¼~69%; B A ¼0.75). We estimate that the interspecific competition could have been avoid by different feeding strategies, although more investigations are still needed to better understand their ecological interactions in the habitats of the southwestern Amazon during the late Quaternary. (J.P. Souza-Filho), acherkin@uga.edu (A. Cherkinsky), matdantas@yahoo.com.br (M.A. Trindade Dantas).
... Considerando essa necessidade, da democratização da ciência, especialmente relacionado à Paleontologia, e às descobertas realizadas no estado de Mato Grosso do Sul, foram colhidas em sites e revistas especializadas informações sobre o tema da paleontologia (Boroni et al., 2020;Carvalho, 2010;Cordeiro, 2017;Oliveira et al., 2017;Pansani;Pacheco, 2016;Salles, 2005;Sheffler et al., 2010). Elaborou-se uma cartilha contendo as principais informações sobre o assunto, assim como os caminhos para se tornar um Paleontólogo no Brasil, buscando despertar o interesse pela temática abordada e suas especificidades As ferramentas utilizadas para a construção da cartilha didática envolveram todo o material já levantado e citado, além do uso da plataforma Canva e do aplicativo livre Sketchbook para organização e edição das imagens. ...
... O estado de Mato Grosso do Sul é uma região importante para o estudo da evolução, paleoecologia, paleoambientes e extinção de mamíferos, mas sua megafauna quaternária permanece pouco estudada. Em seu trabalho foram analisadas amostras de quatro táxons, sendo eles Eremotherium laulillardi, Glyptotherium sp, Holmesina paulacoutoi e Toxodon platensis.Ainda segundo os autores uma espécie de preguiça gigante foi datada, com aproximadamente 10 mil anos antes do presente(Pansani et al., 2019).Também identificaram restos de aligatorideos de grande porte provenientes do rio Formoso, no município de Bonito. Os fósseis foram identificados como provável Melanosuchus, ou jacaré Açu(Geroto;Janolla, 2019). ...
Compreendendo a importância da disseminação e conhecimento relacionados à Paleontologia do Quaternário, é constatada a relevância do estado de Mato Grosso do Sul nesse cenário, assim como seu potencial para novas descobertas. A pesquisa teve por objetivo reunir informações de artigos científicos que apresentassem achados de fósseis do período Quaternário. Essas informações foram agrupadas no presente artigo e serviram de base para criação de uma cartilha informativa contendo conhecimentos básicos sobre a área em si e os caminhos para se tornar um profissional. Foram gerados mapas geológico e de localização de sítios paleontológicos no estado, visando a contribuição para o fortalecimento do interesse e da informação ao público geral. Espera-se contribuir com a divulgação dos estudos realizados na região e que a cartilha seja utilizada como um material didático auxiliando professores da rede pública e privada de ensino, em conteúdos que envolvam a geografia física de Mato Grosso do Sul.
... em sua maioria são datados do Pleistoceno final ao Holoceno inicial, diversas informações têm sido resgatadas, como o paleoambiente e a paleodieta. O uso de ferramentas como os isótopos estáveis têm permitido inferências sobre dieta, clima, vegetação, dentre outros dados paleoecológicos (Neves & Piló, 2003;Auler et al., 2006;Pansani et al., 2019;Dantas et al., 2020;Eltink et al., 2020;Dantas et al., 2021;Omena et al., 2021). ...
... Além disso, é a mistura temporal mais baixa dentre os resultados encontrados em outras cavernas dos estados da Bahia, como a Toca dos Ossos em Ourolândia (~16 mil anos; Pansani et al., 2019), Toca Fria, Iuiu (~17 mil anos; Dantas et al., 2020), Gruta do Ioiô, Iraquara (~22 mil anos; Eltink et al., 2020), e de Minas Gerais, como a Gruta Cuvieri, Lagoa Santa (~18 mil anos; Neves & Piló, 2003;Auler et al., 2006). A mistura temporal é muito inferior às taxas estimadas na Gruta do Baú, em Lagoa Santa, Minas Gerais (~63 mil anos; Auler et al., 2006) e Toca da Barriguda, Campo em Formoso, Bahia (~208 mil anos; Auler et al., 2006). ...
Isotopic paleoecology (δ13c, δ18o) of mammals from the late Pleistocene–Holocene of Ituaçu, Bahia, Brazil. In this paper, the isotopic paleoecology (δ13C, δ18O) of fossils of the mammals Alouatta sp., Cebus sp., Myocastor coypus, Dicotyles tajacu, Tamandua tetradactyla, and Tapirus terrestris collected in Lapa do Bode cave, Ituaçu Municipality, State of Bahia, is described. Radiocarbon ages of 6,480–6,653 Cal yr. BP (14C collagen = 5,790±25 years) were obtained for T. tetradactyla and 27,798–28,221 Cal yr. BP (14C collagen = 23,950±50 years) for M. coypus. The herbivore taxa (T. terrestris, δ13C = -14.9 ‰; Alouatta sp., δ13C = -13.0 ‰; M. coypus, δ13C = -12.7 ‰) had a diet composed mainly of C3 plants (piC3< 80%), indicating forested environment, a similar interpretation also suggested from other taxa that ingested >60% C3 plants such as Cebus sp. (δ13C = -13.1 ‰); D. tajacu (δ13C = -9.7 ‰; T. tetradactyla, δ13C = -11.0 ‰), allowing to suggest that these taxa lived in low-density forests and arboreal savanna habitats. Keywords: caves, paleodiet, carbon isotopes, oxygen isotopes.
... Incomplete zygomatic arches, narrow skulls, long tongues, and simple teeth with no enamel are features of unusual morphology when compared to other herbivore taxa, being most likely morphological influences from an ancestor with insectivore habits (Naples and McAfee 2014). Several studies using different methods have addressed sloth feeding habits, such as dental microwear (e.g., Green 2007Green , 2009; Green and Resar 2012) and mesowear (Saarinen and Karme, 2017), isotopic analysis (e.g., Dantas et al. 2017;Pansani et al. 2019;Omena et al. 2021), coprolite analysis (e.g., Poinar et al. 1998), morphogeometry (e.g., Bargo and Vizcaíno 2008), and muscle reconstruction (e.g., Naples 1985Naples , 1987Naples , 1989, sometimes with diverging conclusions, especially regarding extinct species. ...
... The close affinity between Eremotherium and Nothrotheriops is also an interesting result, as their proposed diet points to a more generalist diet. Eremotherium has been considered a mixed feeder with remarkable ecological elasticity, preferring certain foods depending on local competition and food availability (Dantas et al. 2017;Pansani et al. 2019) but being capable of engaging in what is called "high browsing" or plucking the leaves and other food items from branches far off the ground (McDonald 2005). Its size not only assisted food acquisition but also allowed for a greater amount of thermal inertia that permitted Eremotherium to inhabit many different environments (McDonald 2005). ...
We applied finite element analysis (FEA) in mandibles of nine sloths, including the two extant genera (Bradypus and Choloepus) and seven extinct genera (Eremotherium, Hapalops, Megatherium, Neocnus, Nothrotheriops, Nothrotherium, and Paramylodon). These groups do not present a clear association with feeding habits, but they do seem to indicate an association with ecological specialization: specialized (Group 1: Bradypus, Paramylodon, Hapalops, and Megatherium) or generalized (Group 2: Choloepus, Nothrotherium, Neocnus, Nothrotheriops, and Eremotherium). Thus, we suggest that FEA on 2-D models of sloth jaws could be a useful tool in ecomorphological comparative studies.
... Furthermore, their great height (~6 m), along with the long anterior limbs and large-clawed manus, could have been efficient for branch reaching while displaying a bipedal stance (Farinã et al., 2013). However, E. laurillardi seemed to be ecologically more flexible and able to exploit both browse and grass as supported by recent paleoecological studies from late Pleistocene specimens of the Brazilian Intertropical Region (BIR) (Dantas et al., 2017(Dantas et al., , 2020França et al., 2014;Pansani et al., 2019;Oliveira et al., 2020). ...
... Regarding the South American native ungulate, T. platensis, a grazer diet composed by more abrasive plants is suggested due to its complete hypsodont and hypselodont dentition (Bond et al., 1997). Nevertheless, a wide food plasticity was also reported for this species during the late Pleistocene (Macfadden, 2005;Pansani et al., 2019). This large ungulate could reach around three tons as adults and its ecological niche was supposedly analogous to the extant rhinos (Dantas et al., 2017). ...
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.
... Over the last decade, there has been an effort to better understand the isotopic paleoecology (d 13 C, d 18 O) and chronology ( 14 C AMS, ESR) of mesoherbivores (body mass between 100 kg and 750 kg) and megaherbivores (body mass > 750 kg) that lived in the Brazilian Intertropical Region (BIR) during the Late Quaternary (Dantas et al. 2017 and references therein). Until now, isotopic data and radiocarbon datings have been published for extinct species, such as giant ground sloths (Eremotherium laurillardi, Valgipes bucklandi, Catonyx cuvieri, and Nothrotherium maquinense), giant armadillos (Holmesina paulacoutoi, Glypotherium sp. and Panochthus sp.), camelids (Palaeolama major), horses (Equus (Amerhippus) neogeus), proboscideans (Notiomastodon platensis), and toxodons (Toxodon platensis); as well as for fossils of extant species, like the tapir Tapirus terrestris (Dantas et al. 2017 andreferences therein, Dantas et al. 2019;Pansani et al. 2019;Silva et al. 2019). ...
... Including the data from Iuiu, nowadays only five localities in the BIR have carbon and oxygen isotopic values associated to radiocarbon datings for more than two species with more than 100 kg: Barcelona/Rio Grande do Norte, Poço Redondo/Sergipe, Coronel João S a/Bahia, Andarai/Bahia and Ourolândia/Bahia (Table 1), which could enable us to propose paleoenvironmental reconstructions for all these localities and to compare them. We excluded data from Miranda river, Mato Grosso do Sul (Pansani et al., 2019), since this locality had a major influence from a humid corridor from Amazon, causing these specimens to have lower oxygen isotopic values in comparison with other localities in the BIR. ...
Stable isotopes of carbon and oxygen of fossil specimens are widely used for paleoecological and paleoenvironmental inferences, and there has been an effort to better understand the isotopic paleoecology and chronology of herbivores that inhabited the Brazilian Intertropical Region during the late Quaternary. In the present work, new radiocarbon datings and carbon and oxygen isotopes data for Eremotherium laurillardi, Notiomastodon platensis, Tapirus terrestris, Tayassu pecari, and Mazama gouazoubira are presented, from specimens that lived on Iuiu county (Toca Fria and Jatobá caves), state of Bahia, in the Brazilian Intertropical Region. E. laurillardi was dated as of ∼32 ka BP, representing the oldest direct dating for this species in the Brazilian Intertropical Region, while N. platensis was dated as of ∼25 ka BP. Fossils of the extant species T. pecari, M. gouazoubira, and T. terrestris presented radiocarbon ages of ∼23 ka BP, ∼21 ka BP, and ∼15 ka BP, respectively, showing that some of these species lived in Iuiu during the Last Glacial Maximum. According to our analyses, T. terrestris was the only specialist (δ¹³C = −11.0‰; piC3 = 0.76; BA = 0.49), whereas the remaining taxa were generalists mixed-feeders (δ¹³C = −1.3 to −10.0‰; piC3 = 0.24 to 0.69; BA > 0.58). The paleoenvironment reconstruction in Iuiu and other localities in BIR, during ∼32 ka BP to ∼15 ka BP, allow us to suggest that the dry arboreal to open Savanna habitats (rich in grass and shrubs) were the most common environment.
... However, the former definition of the BIR was contested recently by Oliveira et al. (2017), who suggested its expansion by including the states of Mato Grosso do Sul and São Paulo in the midwest and southeast regions of Brazil, respectively. Pansani et al. (2019) performed a paleoecological study that revealed different isotopic oxygen values for the same Pleistocene megamammals from different regions (midwest and northeast of Brazil). The authors highlighted the problem of delimiting past biogeographical areas, such as the BIR, using only faunistic composition and suggested that further studies on this topic should consider other ecological variables, such as climate and vegetation conditions. ...
South America is a pivotal paleontological setting for Late Quaternary megafaunal research. Nonetheless, its paleobiogeography and paleoecology, and the causes for the recent extinction of megafauna in the Late Pleistocene/Early Holocene are not yet fully understood. This study aimed to investigate the potential geographical distribution and historically intertropical stable areas (HISAs) of South American megafauna. We generated maps using Paleo‐Species Distribution Models for 12 megafaunal taxa (11 herbivores and one carnivore) during interglacial and glacial periods in the Late Quaternary: 120 and 21 ka. Our models, together with isotopic data, show that the HSIAs occurred mainly in low‐altitude plains (<1000 m) and were superimposed on seasonal dry forest biomes. We propose the occurrence of two HSIAs: the West Intertropical Region and the Brazilian Intertropical Region, the latter being redefined. We suggest that the Brazilian Intertropical Region is much smaller than previously proposed, but was still a key zoogeographical region for megafauna in South America during the Late Pleistocene.
... Wenker et al., 1999;Kapoor et al., 2016;Ozga and Ottoni, 2023). N. platensis has been considered a generalist mixed-feeder, with high proportions of different types of vegetation in their diet (França et al., 2015;Dantas et al., 2017;Dantas et al., 2022;Pansani et al., 2019;Asevedo et al., 2020Asevedo et al., , 2021. Their diet typically included abrasive elements, such as grasses, twigs, barks, stems, herbs, foliage and branches (Asevedo et al., 2020), which could have acted to remove dental calculus. ...
Dental calculus, or tartar, is a mineralized biofilm that develops on the teeth, and is often observed on the teeth of the South American proboscidean Notiomastodon platensis . This structure can provide details on paleoecological, paleoenvironmental and paleopathological aspects of a species. However, characterization of tartar in N. platensis is lacking. The aim of this study was to provide a macromorphological characterization of tartar on N. platensis molars, and evaluate its prevalence, distribution patterns and severity. A total of 117 molariforms from Brazilian Quaternary fossiliferous assemblages were analyzed. Thirty‐five (29.9%) molars presented tartar. The majority displayed moderate severity. Calculus was present at least on one inteloph(id) of each molar, and prevailed on the posterior region. It predominated on lower and third molars. Adult individuals showed a predominance compared to juveniles. These patterns in N. platensis are probably due to the susceptible oral environment, molar morphology, mature age and tooth replacement. These results suggest that N. platensis and probably other proboscideans were relatively susceptible to tartar development.
... The megafauna of the Brazilian Intertropical Region (sensu Cartelle, 1999) was rich in large mammals, including species likely indigenous (e. g., Xenorhinotherium bahiensis, Panochthus jaguaribensis) and others with a wide geographic distribution across South America (e.g., Arctotherium brasiliense, Palaeolama major, and Toxodon platensis) (Barbosa et al., 2019b). Although there are many studies on Quaternary megafauna, including paleoecological and paleoenvironmental aspects (e.g., Silva, 2008;Dantas et al., 2017;Pansani et al., 2019;Silva et al., 2019), paleopathological studies are still incipient for some groups of wide occurrence in the fossil record of the Quaternary of South America (e.g., toxodonts and macraucheniids). ...
... In addition, there is a general inability of these studies to link the disappearance of megafauna to a specific climatic mechanism, or to explain why previous and equally extreme changes in the Cenozoic did not have such a selective impact on large-bodied mammals . Quaternary megafauna, including extinct species, generally had very broad and adaptable diets and habitat requirements as evidenced by isotopic studies (Pansani et al., 2019;Pardi and DeSantis, 2021). As such, a purely climate-driven explanation is not possible. ...
The Earth has lost approximately half of its large mammal species (≥45 kg, one-third of species ≥9 kg) over the past 120,000 years, resulting in depauperate megafauna communities worldwide. Despite substantial interest and debate for over a century, the reasons for these exceptionally high extinction rates and major transformation of the biosphere remain contested. The predominant explanations are climate change, hunting by modern humans (Homo sapiens), or a combination of both. To evaluate the evidence for each hypothesis, statistical models were constructed to test the predictive power of prehistoric human and hominin presence and migration on megafauna extinction severity and on extinction bias toward larger species. Models with anthropic predictors were compared to models that considered late-Quaternary (120–0 kya) climate change and it was found that models including human factors outperformed all purely climatic models. These results thus support an overriding impact of Homo sapiens on megafauna extinctions. Given the disproportionate impact of large-bodied animals on vegetation structure, plant dispersal, nutrient cycling and co-dependent biota, this simplification and downsizing of mammal faunas worldwide represents the first planetary-scale, human-driven transformation of the environment.
... Therefore, a common alternative for dating and palaeoecological investigation of Quaternary fossils without collagen preservation relies on the extraction and measurements of hydroxyapatite (e.g. Garrison et al., 2019;Pansani et al., 2019;Asevedo et al., 2021), which has been demonstrated to be a successful tool due to the resistance of the mineral phase of bone and teeth to diagenetic processes (Cherkinsky, 2009). ...
The Santa Elina rock shelter (Central Brazil) stands out with two human occupation layers with ground sloth fossil remains from the Late Pleistocene. Here, we explore the palaeontological aspect of this site. We update the taxonomic assignment of the ground sloth found in the shelter to Glossotherium phoenesis. Radiocarbon dating performed on bioapatite (14 C bioapatite) from two tooth specimens reveal the minimum ages of 14 944-15 239 cal a BP (unit II2) and 22 339-22 534 cal a BP (unit III4), which were converted to collagen using a novel approach and presented the calibrated ages of 17 450-17 906 cal a BP (14 C collagen = 14 547 ± 40) and 25 994-26 396 cal a BP (14 C collagen = 22 042 ± 40). We reinforce the chronology of the oldest unit of Santa Elina with material culture in association with megafauna bones to the Last Glacial Maximum. Carbon isotopic signatures suggest a mixed feeding diet for both specimens. The most recent ground sloth presents a higher isotopic value (δ 13 C = −1.8‰) and narrower niche breadth (B A = 0.50) than the oldest one (δ 13 C = −3.3‰; B A = 0.74). We conclude that G. phoenesis lived in an arboreal savanna habitat during the phases studied. Slightly different oxygen isotopic values (δ 18 O = 26.2‰ and 27.9‰) might suggest a decrease in humidity over time. Our results provide insights into the palaeoecology of the tropical Pleistocene G. phoenesis and the palaeoenvironmental setting of Santa Elina when occupied by early humans and megafauna during the Late Pleistocene.
... Paleoecology studies of Catonyx cuvieri suggest an open C3/C4 and open C3 vegetation and a diet based mainly on C4 grass with some fruits (Dantas et al., 2020). In the Brazilian intertropical region, Equus neogeus was a grazer with a diet consisting predominantly of C4 grasses (Dantas et al., 2017;Pansani et al., 2019). Based on coprolites, Marcolino et al. (2012) proposed a diet of Palaeolama major based on shrubs (C3 plants). ...
The present-day semiarid region of NE Brazil experienced multiple periods of increased precipitation during the Quaternary. They were likely linked to global-scale events (e.g., Heinrich Events) and drove changes in vegetation dynamics, leading to the expansion of rainforest vegetation. Here, we hypothesize that soil features preserved in cave sediments records paleoenvironmental changes induced by global-scale events that affected NE Brazil during the Late Pleistocene-Early Holocene. To test this hypothesis, we analyzed the elemental and isotopic geochemistry composition, bulk sediment mineralogy, soil micromorphological features, and fauna fossil type and content of a well-preserved 6 m cave sediment profile spanning 103 kyr-8 kyr in Toca de Cima do Pilão at the Serra da Capivara National Park. Our approach provides new information on the history of soil formation, vegetation, and climate of NE Brazil during the Late Pleistocene-Early Holocene. The results demonstrated that severe weathering and dense vegetation was the dominant paleoenvironmental conditions during wet periods, when latosolization was the main soil forming process. The evidence for wet and intense weathering periods was the coexistence of speleothems layers with Ferralsol features, such as runiquartz, granular microstructure, Fe nodules and gibbsite formation. Some of these features were found in layers deposited in synchrony with Heinrich Stadial and Younger Dryas periods, suggesting that past soil processes in NE Brazil were affected by those global-scale events. We propose five phases of latosolization in our study area during the last 100 kyr. The first was identified around 80 kyr, the second occurred around 29 kyr. The third coincided with Heinrich Stadial 1 (16 kyr) and the fourth likely occur during the Younger Dryas, and the fifth phase occurred during the middle Holocene.
... Braunn and Ribeiro, 2017). Studies point to dietary plasticity in the species of this suborder, which foraged on plants using both the C 3 and C 4 photosynthetic pathways, and are therefore considered as generalists (Dantas et al., 2017;Braunn and Ribeiro, 2017;Defler, 2018;Pansani et al., 2019;Domingo et al., 2020). ...
... Por intermédio dos fósseis, paleontólogos buscam entender como foram os organismos pretéritos e como estes interagiam entre si e com o meio ambiente. Em seus primórdios, a Paleontologia consistia em, principalmente, descrever, identificar e classificar os fósseis encontrados, mas, nos últimos anos, novas técnicas de análise, como a microtomografia, a análise de isótopos estáveis ou a Paleohistologia (e.g., Maldanis et al., 2016, Pansani et al., 2019, Aureliano et al., 2021, têm surgido e sido utilizadas para revelar cada vez mais detalhes sobre a Biologia e Ecologia dos seres extintos (Sayão & Bantim, 2015). ...
A Paleontologia tem obtido destaque no cenário nacional e internacional nas últimas décadas. O Brasil tornou-se polo importante de pesquisas na área e tem contribuído significativamente para o conhecimento acerca de nosso passado. Entretanto, conteúdos sobre Paleontologia geralmente não são incluídos e trabalhados nas salas de aula brasileira da Educação Básica, por não constarem nos documentos oficiais regulatórios. Este trabalho buscou analisar trabalhos publicados nos últimos dezesseis anos sobre a inclusão da Paleontologia no Ensino Básico do Brasil, além de verificar de que forma os pesquisadores sugerem a inclusão do tema no currículo escolar. Foram analisados vinte trabalhos cujo objetivo era investigar ou sugerir atividades sobre Paleontologia em salas de aulas de diferentes níveis do Ensino Básico. Encontrou-se que existem poucos trabalhos com sugestões de atividades de ensino sobre Paleontologia e que essas foram pensadas, principalmente, para as aulas de Ciências e Biologia, deixando de lado a potencialidade de aplicação em outras disciplinas.
... Argentina, Domingo et al., 2012;Bocherens et al., 2016) while others infer a preference for C 4 plants (e.g. Southern and Midwest Brazil, Lopes et al., 2013;Pansani et al., 2019). From a palaeoecological point of view, these results indicate that Toxodon was possibly a generalist taxon, and its dietary preference would be related to the ecological pressures of each environment and/or temporal period. ...
During the Pleistocene intense climatic changes occurred corresponding with the alternation of inter-glacial and glacial periods. By means of stable isotope analysis on fossil mammals, this research allows the assessment of the palaeoecological and palaeoclimatic conditions, including the possible scenarios for the atmospheric circulation pattern during three key phases of the late Pleistocene in the Pampean region of Argentina: Last Interglacial (LIG, MIS 5e; unpublished data), Last Glacial Maximum (LGM; 28,170e19,849 cal BP yrs), and post-Last Glacial Maximum (post-LGM, 17,281e11,500 cal BP yrs). Tooth enamel d 13 C values of mammals from the Last Glacial Maximum showed an increase in C 4 plants consumption compared to the other two phases studied, which may be related to a reduction in forest cover due to a combination of environmental factors such as decreased pCO 2 atm and increased aridity. We evaluated mean annual precipitation (MAP) and mean annual temperature (MAT) variability from tooth enamel d 13 C and d 18 O values, which showed a greater variation in precipitation between phases than in temperature. This result enabled us to propose two climate regimes for the studied temporal sequence, an arid-temperate regime, and a humid-temperate regime, which were mostly regulated by variations in atmospheric circulation.
... In the last years, several papers deal with the paleoecology of mesomegammamals herbivores from this region, helping to understand better the ecosystems and the dynamic between these herbivores species in the late Pleistocene of BIR (Asevedo et al., 2012;Dantas et al., 2017Pansani et al., 2019;Oliveira et al., 2020;Omena et al., 2021). ...
This study presents isotopic analyses of Panthera onca from the late Pleistocene of the Brazilian Intertropical Region. This paper focuses on the paleoecology of this large cat and is of major importance to understand ecological niches in evolutionary time. Carbon and oxygen stable isotope compositions were determined from the structural carbonate of enamel for two fossils of Panthera onca found in caves in Bahia, Brazil. Isotopic data available of large faunivores and other extinct and extant herbivorous taxa from the late Pleistocene of the Brazilian Intertropical Region were used for paleoecological interpretations. Carbon and oxygen isotopic values from P. onca allow us to suggest that these individuals lived in arboreal savanna habitat between 26 and 33 kyr BP and could feed mainly on Nothrotherium maquinense, Tapirus terrestris and Alouatta sp., being a specialist. The isotopic niche overlap with Smilodon populator and Arctotherium wingei was high, while with Protocyon troglodytes was low.
... Measurements of carbon isotope (d 13 C) ratios are essential for (paleo)environmental studies, such as those regarding the carbon cycle, past food consumption by pre-historic societies, paleovegetation reconstructions, soil dynamics, aspects regarding animal migration and food consumption, etc. (Rayner et al., 1999;Calo and Cort es, 2009;Pansani et al., 2019;Novello et al., 2019). (Reuter et al., 2009;Novello et al., 2012Novello et al., , 2016Novello et al., , 2018Apa estegui et al., 2014Apa estegui et al., , 2018Vuille et al., 2012;Kanner et al., 2013;Wang et al., 2017). ...
Due to the many factors controlling δ¹³C values in stalagmites, complicating their paleoclimatic and paleoenvironmental interpretation, most studies do not present δ¹³C values, but instead focus mainly on δ18O values. This is also the case for most cave studies from tropical South America, where many new δ18O stalagmite records covering the last millennia were recently published. Here, we review the δ¹³C values in stalagmites, investigating the influence on this proxy of local hydroclimate, altitude, temperature and vegetation types, by employing a new dataset composed of published and unpublished carbon isotope records from various sites in tropical South America. The main factors influencing δ¹³C values are associated with the local hydroclimate, followed by minor effects from temperature. Most of the isotopic records show a significant correlation between the δ¹³C and δ18O values, indicating a close relationship between local hydroclimate and atmospheric convective processes related to the South American Monsoon System.
... Measurements of carbon isotope (δ 13 C) ratios are essential for (paleo)environmental studies, such as those regarding the carbon cycle, past food consumption by pre-historic societies, paleo-vegetation reconstructions, soil dynamics, aspects regarding animal migration and food consumption, etc. (Rayner et 40 al., 1999;Calo and Cortés, 2009;Pansani et al., 2019;Novello et al., 2019). However, δ 13 C values of speleothems are generally considered difficult to interpret and, in most cases, are not reported in isotopic studies based on speleothems. ...
Due to the many factors controlling δ13C values in stalagmites, complicating their paleoclimatic and paleoenvironmental interpretation, most studies do not present δ13C values, but instead focus mainly on δ18O values. This is also the case for most cave studies from tropical South America, where many new δ18O stalagmite records covering the last millennia were recently published. Here, we test the influence of local hydroclimate, altitude, temperature and changing vegetation types on δ13C values in stalagmites, by employing a new dataset (named δ13C_2k_SA, https://doi.pangaea.de/10.1594/PANGAEA.919050) composed of published and unpublished carbon isotope records from various sites in tropical South America. Most locations were dominated by C3 plants over the last two millennia and are characterized by speleothem δ13C values more depleted than −6 ‰. The main factors influencing δ13C values are associated with the local hydroclimate, followed by minor effects from temperature. Most of the isotopic records show a significant correlation between the δ13C and δ18O values, indicating a close relationship between local hydroclimate and atmospheric convective processes related to the South American Monsoon System.
... The proportion of resources consumed (p i C 3 = 57%; p i C 4 = 43%) suggest an habitat with heterogeneous landscapes with plants of both C 3 /C 4 photosynthetic pathways during the Late Pleistocene in Goiás. Similar δ 13 C results were observed in the specimen of E. laurillardi from Miranda River, Mato Grosso do Sul state (UGAMS 34133: δ 13 C = − 12.77‰; Table 2), but the more negative value indicate a diet with predominance of C 3 plants (p i C 3 = 98%; Pansani et al., 2019). A generalist diet are also interpreted for E. laurillardi from northeastern Brazil, although these specimens have more positive values that indicates a higher proportion of C 4 plants on diet (δ 13 C = − 9.2‰ to 0,91‰; Table 2) and differ from those in the midwestern region (ANOVA, F obs. = 5.69, p = 0.03). ...
... Studies using the isotopic geochemical approach for paleoecology in South America are still scarce. Inferences on dietary information of herbivorous mammals can depict different vegetation in different latitudes, offering an additional approach to the understanding of Quaternary (MacFadden et al., 1999;Sánchez et al., 2004;Dantas et al., 2013Dantas et al., , 2017Lopes et al., 2013;Franca et al., 2015;Pansani et al., 2019). The interpretation of vertebrate fossils deposition in caves, which would occurred synchronous during the transition of the Pleistocene to the Holocene in Brazilian (Cartelle, 1992(Cartelle, , 1995, were demonstrated to be more complex (Auler et al., 2006). ...
Gruta do Ioiô is a cave part of Iraquara carstic system (Salitre Formation, Una Group). Located in the region of
the Chapada Diamantina, northeastern Brazil, this partially submerged cave has yielded abundant fossil remains
that until now included Siluriformes, an alligatorid crocodilian and a set of mammals, such as representatives of
Mustelidae, Rodentia and Chiroptera. Besides the record of Palaeolama major (Camelidae), Pecari
tajacu (Tayassuidae), both yielded from subaquatic site, Puma concolor, Leopardus pardalis (Felidae), Chrysocyon
brachyurus (Canidae), and a Didelphidae indet. were yielded from newly described subaerial site. Taphonomic
features, such as weathering, transport, breakage, bones and taxonomic representation, demonstrate that
bioestrationomic and fossildiagenetic conditions varies between fossiliferous accumulations in the cave, and
differences are still observed in the same fossil-bearing site (subaerial). The radiocarbon ages indicate the occurrence of Leopardus pardalis at 30,351–30,862 yr cal BP, Palaeolama major at 24,854–25,379 yr cal BP and
Pecari tajacu at 8170–8336 yr cal BP. It extends the time range of Gruta do Ioiô fossils from the Late Pleistocene
to the Early-Middle Holocene, encompassing the Last Glacial Maximum. Paleoecological inferences provided by
stable isotopes (δ13C) suggest great proportion of diets based on C3 plants along the trophic levels, suggesting a
denser forest environment and more humid conditions in the region of Gruta do Ioiô cave during the Quaternary.
The record of taxa, such as Myocastor coypus (a semiaquatic rodent currently distributed in subtropical and
temperate South America) and Chrysocyon brachyurus (a typical dweller of open grasslands) shows that past
landscape, composed by forests and/or savannic vegetations, contrasts with xeric arboreal scrubland that currently covers the area.
We inferred the annual isotopic diet (δ 13 C) of an individual of the giant ground sloth Eremotherium laurillardi found in Toca dos Ossos (Ourolândia, Bahia, Brazil) through the extension of its third inferior molar. This individual lived in the region at 40,779-39,617cal yr BP. One year of its life was recorded in a length of 67 mm in the tooth. Two years were recorded in this molariform, during which the diet and climate did not change much, and substantial precipitation occurred during the middle of the year, which is in opposition to the modern pattern. The mean carbon (μδ 13 C = −13.9 ± 1.8‰) and oxygen (μδ 18 O = 22.5 ± 2.9‰) isotopic values were similar to values for other individuals of the species found in the same cave but different from the values found in other localities of the Brazilian Intertropical Region, which allows us to suggest that this region had more precipitation and lower temperatures in comparison to today. The oxygen isotopic values found in dated fossils of E. laurillardi and from two other taxa found in the same cave (Toxodon platensis, and Notiomastodon platensis) could help in the understanding of the climatic variation that occurred in the region.
Vertebrate paleoecology is a field that has been drawing the interest of Brazilian researchers. Aiming to characterize the
current overview of the field, we searched for articles published in the last decade and gathered them into groups according
to year of publishment, main theme, and taxonomic group studied. We noticed that the amount of papers increased notably
in the last two years, specially those focusing on the feeding habits of the Quaternary megafauna; works regarding other
groups were comparatively scarse. We also noticed inconsistences in the usage of terms and ecological concepts, as well as papers that briefly commented on the life of extinct animals. We suggest that there is a niche for growth in works in this field, which would allow broader discussions concerning the Brazilian vertebrate paleofauna.
Camelids have been known in South America since the late Pliocene, where they arrived from North America as part of the Great American Biotic Interchange (GABI). They became extinct in North America by the late Pleistocene, while surviving in the Southern Cone of South America and in high altitudes of the Andean region. Extinct South American camelids are generally included in the genera Palaeolama and Hemiauchenia, members of which are larger than modern species. We describe here a new, small species of the genus Hemiauchenia based on late Pleistocene specimens previously assigned to Lama guanicoe. This specimen lived in northeastern Brazil at 22 345–21 907 cal a bp, and had a diet composed mainly of C3 plants.
RESUMO A porção Sudoeste do Estado de Mato Grosso do Sul tem revelado um potencial paleontológico da megafauna do Quaternário, destacando-se a Serra da Bodoquena e a Bacia Sedimentar do Pantanal. O objetivo deste trabalho foi realizar um levantamento sobre a ocorrência de fósseis da megafauna do Quaternário de Mato do Grosso do Sul e discutir como estas novas descobertas auxiliam na compreensão dos paleoambientes e paleoecologia locais. Apesar de pouco estudadas, a maioria das unidades litoestratigráficas localizadas no Sudoeste do estado têm apresentado registros fossilíferos, principalmente ao longo de canais fluviais e cavernas. Dentre os registros osteológicos fósseis recuperados destacam-se as seguintes Ordens: Xenarthra, Perissodactyla, Cetartiodactyla, Litopterna, Notoungulata, Proboscidea, Carnivora e Crocodilia. Essas ordens conviveram mutuamente em um ambiente submetido às variações paleoclimáticas, especialmente no Pleistoceno de modo a influenciar seu hábito alimentar, comportamental, dispersão e distribuição geográfica. Palavras-Chave: Megafauna do Quaternário, Fósseis, Estado de Mato Grosso do Sul.
McDonald HG 2021. Yukon to the Yucatan: Habitat partitioning in North American Late Pleistocene ground sloths (Xenarthra, Pilosa). Journal of Palaeosciences 70(2021): 237-251. The late Pleistocene mammalian fauna of North America included seven genera of ground sloth, representing four families. This cohort of megaherbivores had an extensive geographic range in North America from the Yukon in Canada to the Yucatan Peninsula in Mexico and inhabited a variety of biomes. Within this latitudinal range there are taxa with a distribution limited to temperate latitudes while others have a distribution restricted to tropical latitudes. Some taxa are better documented than others and more is known about their palaeoecology and habitat preferences, while our knowledge of the palaeoecology of taxa more recently discovered remains limited. In order to better understand what aspects of their palaeoecology allowed their dispersal from South America, long-term success in North America and ultimately the underlying causes for their extinction at the end of the Pleistocene more information is needed. A summary overview of the differences in the palaeoecology of the late Pleistocene sloths in North America and their preferred habitats is presented based on different data sources.
The palaeoecology of megamammals has been commonly accessed by stable isotope. Particularly in the Americas, this approach has been focusing efforts on the study of intertropical species, especially from a key paleozoogeographical region in the Late Quaternary of South America: the Brazilian Intertropical Region (BIR). Here we present an isotopic study (δ13C) conducted on bioapatite samples of Smilodon populator, Protocyon troglodytes and Arctotherium wingei from the BIR. We discuss their potential prey preferences, niche width and overlap, and paleoenvironmental reconstitutions. Our results suggest a generalist carnivorous diet for P. troglodytes (δ13C = – 5.0 ‰; BA = 0.83), a specialist C3 herbivorous diet and opportunistic scavenger behaviour for A. wingei (δ13C = – 11.0 ± 2.1 ‰; BA = 0.00), and a specialist carnivorous diet for S. populator (δ13C = – 8.5 ± 1.6 ‰; BA = 0.06). Within the Late Pleistocene of the BIR, P. troglodytes possibly inhabited open savanna-like environments, while S. populator and A. wingei occupied arboreal savanna forests. An atypical preference for small and medium-size prey for the predator S. populator, and a mainly herbivorous diet with a slight amount of meat for the bear A. wingei is also discussed.
Prehistoric and recent extinctions of large-bodied terrestrial herbivores had significant and lasting impacts on Earth’s ecosystems due to the loss of their distinct trait combinations. The world’s surviving large-bodied avian and mammalian herbivores remain among the most threatened taxa. As such, a greater understanding of the ecological impacts of large herbivore losses is increasingly important. However, comprehensive and ecologically-relevant trait datasets for extinct and extant herbivores are lacking. Here, we present HerbiTraits , a comprehensive functional trait dataset for all late Quaternary terrestrial avian and mammalian herbivores ≥10 kg (545 species). HerbiTraits includes key traits that influence how herbivores interact with ecosystems, namely body mass, diet, fermentation type, habitat use, and limb morphology. Trait data were compiled from 557 sources and comprise the best available knowledge on late Quaternary large-bodied herbivores. HerbiTraits provides a tool for the analysis of herbivore functional diversity both past and present and its effects on Earth’s ecosystems.
Stable isotopes in enamel, dentin, and bone hydroxyapatite are an important tool in the investigation of the palaeoecology of extinct organisms and are applied as proxies for different environmental parameters (e.g. diet, temperature, guild) that assist in reconstitutions of past environments. Tooth and bone samples of late Pleistocene Toxodon platensis, Eremotherium laurillardi, Notiomastodon platensis, Glyptotherium sp., Hippidion principale, Xenorhinotherium bahiense and Nothrotherium maquinense from several localities in Brazilian Intertropical Region, had δ ¹³C and δ ¹⁸O analysed to infer their paleodiet, guild and niche breadth that allow a reconstruction of past environment in which they lived. Including isotopic data for the horse Equus (Amerhippus) neogeus, the giant lama Palaeolama major, the Cingulatas Panochthus sp. and Holmesina paulacoutoi, and the giant ground sloth Valgipes bucklandi, we can suggest that the Brazilian Intertropical Region presented three guilds: browsers (N. maquinense, V. bucklandi, X. bahiense), mixed-feeders (H. principale, E. laurillardi, T. platensis, N. platensis, P. major, Panochthus sp., H. paulacoutoi) and grazer (E. (A.) neogeus, Glyptotherium sp.). These results indicate a dry environment with mixed vegetation with a predominance of open savanna, suggesting that the area at the time was similar to the current in more arid and open areas of the shrub savanna.
Climate warming and human landscape transformation during the Holocene resulted in environmental changes for wild animals. The last remnants of the European Pleistocene megafauna that survived into the Holocene were particularly vulnerable to changes in habitat. To track the response of habitat use and foraging of large her-bivores to natural and anthropogenic changes in environmental conditions during the Holocene, we investigated carbon (δ 13 C) and nitrogen (δ 15 N) stable isotope composition in bone collagen of moose (Alces alces), European bison (Bison bonasus) and aurochs (Bos primigenius) in Central and Eastern Europe. We found strong variations in isotope compositions in the studied species throughout the Holocene and diverse responses to changing environmental conditions. All three species showed significant changes in their δ 13 C values reflecting a shift of foraging habitats from more open in the Early and pre-Neolithic Holocene to more forest during the Neolithic and Late Holocene. This shift was strongest in European bison, suggesting higher plasticity, more limited in moose, and the least in aurochs. Significant increases of δ 15 N values in European bison and moose are evidence of a diet change towards more grazing, but may also reflect increased nitrogen in soils following deglaciation and global temperature increases. Among the factors explaining the observed isotope variations were time (age of samples), longitude and elevation in European bison, and time, longitude and forest cover in aurochs. None of the analysed factors explained isotope variations in moose. Our results demonstrate the strong influence of natural (forest expansion) and anthropogenic (deforestation and human pressure) changes on the foraging ecology of large herbivores, with forests playing a major role as a refugial habitat since the Neolithic, particularly for European bison and aurochs. We propose that high flexibility in foraging strategy was the key for survival of large herbivores in the changing environmental conditions of the Holocene.
Carbon isotopic signatures recorded in vertebrate tissues derive from ingested food and thus reflect ecologies and ecosystems. For almost two decades, most carbon isotope-based ecological interpretations of extant and extinct herbivorous mammals have used a single diet–bioapatite enrichment value (14‰). Assuming this single value applies to all herbivorous mammals, from tiny monkeys to giant elephants, it overlooks potential effects of distinct physiological and metabolic processes on carbon fractionation. By analysing a never before assessed herbivorous group spanning a broad range of body masses—sloths—we discovered considerable variation in diet–bioapatite δ¹³C enrichment among mammals. Statistical tests (ordinary least squares, quantile, robust regressions, Akaike information criterion model tests) document independence from phylogeny, and a previously unrecognized strong and significant correlation of δ¹³C enrichment with body mass for all mammalian herbivores. A single-factor body mass model outperforms all other single-factor or more complex combinatorial models evaluated, including for physiological variables (metabolic rate and body temperature proxies), and indicates that body mass alone predicts δ¹³C enrichment. These analyses, spanning more than 5 orders of magnitude of body sizes, yield a size-dependent prediction of isotopic enrichment across Mammalia and for distinct digestive physiologies, permitting reconstruction of foregut versus hindgut fermentation for fossils and refined mean annual palaeoprecipitation estimates based on δ¹³C of mammalian bioapatite.
The state of Mato Grosso do Sul, Brazil, has revealed an important paleontological
potential of Quaternary deposits, especially because of the fossil richness in caves and
rivers of the Serra da Bodoquena region. This study presents new taxonomic data of
specimens collected from a new fossiliferous locality of the Pleistocene megafauna in this
region, the Miranda River (Miranda, MS). Among the material that has been identified
are fossil remains of Megatheriidae, Mylodontidae, Glyptodontinae, Pampatheriidae and
Toxodontidae. It is important to mention the novel occurrence of the Pampatheriidae
Holmesina, which fills a paleobiogeographic gap in South America.
Studies regarding Quaternary mammals from the Serra da Bodoquena (South-western Brazil, state of Mato Grosso do Sul) are scarce. In the region, the Fadas Cave has been an important paleontological site. Remnants of Pleistocene fauna were collected along a river channel inside the cave. It is the first record of Arctotherium, Scelidotheriinae and Nothrotheriinae in the Serra da Bodoquena. Smilodon populator, Eremotherium laurillardi, Gomphotheriidae and Glyptodontinae, already known for the region, were also identified. These new occurrences allow us to redefine the paleozoogeographical distribution of some of the aforementioned taxa. Herein we propose the expansion of the range of the Brazilian Intertropical Region, which should include Mato Grosso do Sul and São Paulo. The state of Rio Grande do Sul keeps a greater paleozoogeographical affinity to others temperate zones from Argentina and Uruguay. Taxa associated to open environments indicate the existence of large areas of savannas during the late Pleistocene in the Serra da Bodoquena.
The exact extent, by which the hydrologic cycle in the Neotropics was affected by external forcing during the last deglaciation, remains poorly understood. Here we present a new paleo-rainfall reconstruction based on high-resolution speleothem δ18O records from the core region of the South American Monsoon System (SAMS), documenting the changing hydrological conditions over tropical South America (SA), in particular during abrupt millennial-scale events. This new record provides the best-resolved and most accurately constrained geochronology of any proxy from South America for this time period, spanning from the Last Glacial Maximum (LGM) to the mid-Holocene.
This chapter reviews information about the extinct fauna that lived in the Brazilian Intertropical Region (BIR) between 64 and 10 ka B.P. Data from the available literature regarding dating (14C, ESR, U-series) and paleodiet reconstruction (δ13C) for some of taxa of the BIR are herein presented. Furthermore, paleoenvironmental reconstructions of two climatic moments are presented, one at 64 ka, and another between 27 and 10 ka B.P.
Recent geological studies demonstrate that the Isthmus of Panama emerged some 10 m.y. earlier than previously assumed. Although absent today in Panama, Central American savanna environments likely developed in connection with the onset of Northern Hemisphere glaciations. As is widely recognized, most of the mammals crossing the isthmus since 2.5 Ma lived in savannas. Could climate-induced vegetational changes across Panama explain the delayed migration of mammals, rather than terrestrial connectivity? We investigate the congruence between cross-continental mammal migration and climate change through analysis of fossil data and molecular phylogenies. Evidence from fossil findings shows that the vast majority of mammals crossed between South and North America after ca. 3 Ma. By contrast, dated mammal phylogenies suggest that migration events started somewhat earlier, ca. 4-3 Ma, but allowing for biases toward greater ages of molecular than geologic dating and uncertainties in the former, we consider this age range not to be significantly earlier than 3 Ma. We conclude that savanna-like environments developed in response to the vast Laurentide ice sheet at the first Quaternary glaciation triggered the initiation of the Great American Biotic Interchange in mammals.
The fossil xenarthrans include giant forms, the ground sloths (Tardigrada), characteristic of the mammal fauna of the Pleistocene of South America. Although most authors agree in considering them as herbivorous, these forms have not been studied in terms of detailed morpho-functional analyses of their masticatory apparatuses. The aim of this work is the study the masticatory apparatus of the large Pleistocene ground sloths Glossotherium robustum, Lestodon armatus, Mylodon darwini and Scelidotherium leptocephalum (Mylodontidae) applying biomecanichal and morphogeometrical methods, and to compare with the information obtained for Megatherium americanum (Megatheriidae). The results are integrated with recent ecomorphological analyses that include three variables (hypsodonty index, dental occlusal surface area and relative width and shape of the muzzle) providing useful information for the inference of dietary habits and to propose a niche partitioning among these species. Glossotherium robustum and Lestodon armatus, the wide-muzzled sloths, were mostly bulk-feeders (i.e. ingest great amounts of food with each bite; probably grass and herbaceous plants). Mylodon darwini and Scelidotherium leptocephalum, the narrow-muzzled sloths, were mixed or selective-feeders (i.e. select plants or plant parts; grass and/or tree and shrubs foliage). The tooth design of mylodontids indicates that teeth were used mainly for crushing and grinding turgid and fibrous items respectively. Megatherium americanum was probably the most selective feeder among these sloths, and selectively fed on particular plants (shrubs) or plant parts (leaves, twigs, fruits). Its dentition was designed mostly for cutting soft but tough items which might include flesh, leaving open the possibility of an omnivorous diet.
THE PALEONTOLOGY IN THE MATO GROSSO
DO SUL STATE: KNOWN FOSSILS AND OUTCROPS. The
knowledge about the fossiliferous record in the Mato
Grosso do Sul state, Brazil, is still insufficient,despite
the first citation´s fossil occurred in the second half of
the nineteenth century. The biggest concentration of
palaeontological work is on the Urucum Ridge,
Corumbá Municipality, resulted from commercial
interest in the deposits of iron, manganese and calcium
in Jacadigo and Corumbá groups. Some geological
units abundantly fossiliferous in other states almost
haven’t fossils in Mato Grosso do Sul. This absence of
fossils, however, doesn´t reflect the reality of the
record. It’s the result of the small number of
researchers who have been working in the state and the
limited number of Geology and Paleontology courses in
universities. In order to facilitate and encourage
researches about fossil material in the state, it was
conducted this paleontologic survey that shows fossils
and fossiliferous localities known in Mato Grosso do
Sul, with a stratigraphic record from the Late
Proterozoic to the Holocene.
The highly peculiar masticatory apparatus of glyptodonts is studied. The general morphology of the skull is analysed using a morphometric procedure, e.g. the Resistant Fit Theta Rho Analysis, which allows comparison among different biological forms. In this case, a large terminal form, the late Pleistocene genus Glyptodon, is compared with the smaller primitive Miocene genus Propalaehoplophorus, and with the generalised Recent armadillo Chaetophractus. The masticatory musculature of glyptodonts is reconstructed. Their tooth form and wear facets, as well as their mandibular symphysis and jaw joint, are analysed. A model of jaw movement is constructed based on these analyses. It is demonstrated that the masticatory apparatus of glyptodonts had undergone a telescoping process, which was already underway in the most ancient forms whose skull is known. This process created problems in regard to the way stresses produced by mastication were absorbed by the mandible, and therefore it might be regarded as non-adaptive. Some functional explanatory hypotheses are discussed, such as a requirement of keeping the moment of the weight of the cranium small enough to be counterbalanced by the neck muscles, or fitting the head into the armour.
The contemporary South American mammalian communities were determined by the emergence of the Isthmus of Panama and consequence on by profound climatic oscillations during the Pleistocene. Horses and gomphotheres were two very conspicuous groups of immigrant mammals from North America that arrived in South America during the Pleistocene. This study compiles updated data on the phylogeny, systematic and ecology of both groups in South America. The horses in South America are represented by two genera: Hippidion and Equus; and gomphotheres by other two genera, Curvieronius and Stegomastodon. Both genera of horses include small (Hippidion devilei, Hippidion saldiasi, Equus andium and Equus insulatus) and large forms (Equus neogeus and Hippidion principale), which dispersed into South America using two different routes. The possible model for this dispersion indicates that the small forms used the Andes corridor, while larger horses dispersed through the Eastern route and through some coastal areas. In the case of gomphotheres, Cuvieronius and Stegomastodon reached South America in two independent dispersal events, and Cuvieronius dispersed across the Andean corridor, while large Stegomastodon spread along the eastern route. Horses and gomphotheres present values of δ13C from woodlands to C4 grasslands. Hippidion presents lower values of δ13C than Equus in the late Pleistocene, whereas the gomphotheres diverge the value of δ18O reflecting that Cuvieronius inhabited the Andean corridor and Stegomastodon dispersing through eastern plains. The gomphothere and horse species recorded in South America became extinct at the time that humans arrived. This article is protected by copyright. All rights reserved
Values for δ13C and δ18O obtained from molar samples from three individuals pertaining to Glyptotherium sp. from Cedral (San Luis Potosí, México) are provided and are utilized to infer general aspects of glyptodont diet and habitat. On average this animal showed a C3/C4 mixed diet, with a high consumption of C4 plants. Comparisons of the δ13CVPDB and δ18OVPDB values for glyptodonts with horses, mastodons, mammoths and tapirs from the same locality show that glyptodonts from Cedral lived in an open habitat.
A report on fossil remains of carnivores from the Quaternary of Serra da Bodoquena (Mato Grosso do Sul, Brazil), recovered from two limestone flooded caves, is presented. A total of six species could be identified belonging to three carnivore families, namely Felidae (Smilodon populator, Panthera onca, Leopardus braccatus), Canidae (Protocyon troglodytes, Chrysocyon brachyurus) and Mustelidae (Pteronura brasiliensis), a mosaic of extinct and extant species presumably related to the Holo-Pleistocene fauna of the region. These findings support in part previous suggestions of a paleoecological scenario of open savannas rich in wetlands for the Quaternary environment of Serra da Bodoquena.
Remains of Eremotherium, representing a large-sized megatheriid ground sloth, are known from localities in North, Central, and South America. Usually these remains are currently assigned to the following three species, based largely on geographic provenance: E. laurillardi (Lund), E. mirabile (Leidy), and E. rusconii (Schaub). However, two large, recently recovered collections of Eremotherium remains from Jacobina, Bahia, Brazil, and Daytona Beach, Florida, USA, do not support the separation of these species. Instead, these collections demonstrate the existence of a single Panamerican species. The range of variation is larger than was suspected and the morphological characteristics used in species distinction are not diagnostically valid.The valid name for this species is E. laurillardi (Lund, 1842). The type is a juvenile molariform (ZMUC 1130) from the Pleistocene of Lagoa Santa, Minas Gerais, Brazil. E. mirabile (Leidy, 1855) and E. rusconii (Schaub, 1935) fall as junior synonyms.
The objectives of the present study were to (1) provide new dates of Notiomastodon platensis (Ameghino,
1888) fossils from the Brazilian Intertropical Region, derived from Electron Spin Resonance (ESR); (2)
propose a timeline for the occurrence of N. platensis in South America based on published data (ESR, 14C,
230Th/234U) and, finally, (3) propose a geographic distribution for the species over the period between
21 ka (Last Glacial Maximum) and 120 ka (Interglacial period). The new dates presented here, together
with the available estimates, indicate that the species occurred in South America between at least 530 ka
and 6 ka (middle Pleistoceneeearly Holocene). The Paleo-Species Distribution Models created for the
21 ka and 120 ka periods overlapped with the distribution of dry forest habitats during the Last Glacial
Maximum, which clearly indicates that the species was associated with this type of vegetation.
The gomphothere assemblage from the Pleistocene of Águas de Araxá (Minas Gerais State, Brazil) is composed of several isolated teeth, cranial and postcranial fragments assigned to a single population of Notiomastodon platensis. The age profile suggests decline of the population, due to the large amount of senile and mature adult individuals. The mortality event probably occurred during a long period of low humidity, which could cause a mass death of the proboscideans around water refuges. The ancient feeding ecology of these gomphotheres was reconstructed through stereomicrowear and plant microfossils from teeth calculi, using molars from four age classes. The enamel microwear patterns were recognized according to published studies, whereas the average scratch and pit values were compared to an extant ungulates database. The plant microfossils were chemically recovered and microscopically analyzed. Isotopic analyses of the South American gomphotheres suggest a wide dietary range for N. platensis, except for two localities: Santiago del Estero (Argentina) and La Carolina (Ecuador). For these, isotope analyses suggested an exclusive C4 diet, whereas all other South American localities studied so far indicate an exclusive C3 diet or a mixed C3 and C4 diet. The results also support the apparent latitudinal gradient of C3/C4 grasses. The stereomicrowear analyses for N. platensis exhibited average scratch and pit values, which places it within the extant mixed-feeder morphospace. The higher frequency of fine scratches indicated the ingestion of C3 grasses. Alternatively, the presence of coarse and hypercoarse scratches along with gouges and large pits suggested the ingestion of foliage and lignified portions. The plant microfossil analysis recovered fragments of a conifer tracheid and vessel elements with a ray of parenchyma cells, which corroborates the consumption of wood plants. Also, pollen grains (Polygonaceae), spores (Polypodiaceae) and fibers were found in the samples. According to the results, the Águas de Araxá gomphotheres were feeding generalists and consumed wood elements, leaves and C3 grasses.
South American climates during the Pleistocene and Holocene are poorly known, especially in the lowlands east of the Andean ranges. However, there is relatively good biostratigraphic and climatic information for the late Lujanian and Platan local ages (latest Pleistocene to Holocene) of the Pampas region. Most of the climatic data from the Pampean area are based on land mammal assemblages, pollen records, and geology. Contrasting with North American faunal associations, there are many non-analogue assemblages in the Holocene of the Pampean area. The climate was arid and relatively cold during most of the early Lujanian. However, several relatively wet and warm events are suggested by the presence of subtropical mammals and evidence of tchernozoid paleosoils. The late Lujanian is well represented by the fossiliferous sediments of the La Chumbiada and Guerrero members of the Luján Formation (ca. 30,000 and 21,000–13,000 yr B.P., respectively), cropping out in stream valleys in the Buenos Aires Province. Mammal assemblages suggest a change from a temperate to a cool climate from the La Chumbiada Member to the Guerrero Member, the latter representing the last glacial maximum. The lower portion of the eolian La Postrera Formation has been dated at 11,000–8000 yr B.P. This section was deposited on basin divides under dry and cool conditions. The mammal association was similar to that of the Gueffero Member and includes the last megaherbivore mammals in South America (e.g. Megatherium americanum). Mammals occurring in Platan beds usually indicate dry but not cool conditions. Warm and probably wetter conditions were detected in continental beds deposited synchronously with a mid-Holocene marginal marine ingression (ca. 7000–6000 yr B.P.). A Holocene non-analogue assemblage of subtropical mammals and dry/cold indicators occurred at latitude 38°30′S at ca. 2000 yr B.P. Subtropical mammals that require wetter conditions have been migrating southwards in the Pampean region since 1500–1000 yr B.P. Eolian sediments in the La Postrera Formation dated ca. 440 yr B.P. yielded an arid to semiarid mammal assemblage which could relate to the Little Ice Age period. Remarkably, most of the present-day manual biocenoses and climatic conditions in the Pampas seem to have been recently established. Paleogeographic maps for the last glacial maximum and the mid-Holocene are also provided.
To reconstruct the paleodiet and habitat preference of gomphotheres, we measured the carbon and oxygen isotope composition of 68 bone and tooth samples for three species of Gomphotheriidae from 24 different localities (Argentina, Bolivia, Ecuador, Chile, and Brazil). Additionally, we measured the isotopic oxygen in the phosphate of 30 samples to control diagenetic alteration. We calculated the correlation between pairs of δ18Op–δ18Oc values for enamel, dentine, and bone, taken from the same individual in order to verify whether the oxygen of structural apatite carbonate was in equilibrium with body water. Because of the good correlation obtained among pairs of the three skeletal components, we considered the δ13C results of all components to be equally representative of both gomphothere groups, and we used them collectively in the analysis of the data. To compare the different groups of specimens, we divided the samples into six groups, taking into account their taxonomy as well as their geographic and stratigraphic distribution. Cuvieronius specimens from Chile were exclusively C3 plants eaters, whereas specimens from Bolivia and Ecuador had a mixed C3-C4 diet. Stegomastodon showed a wider range of dietary adaptations. Specimens from Quequén Salado in Buenos Aires Province were entirely C3 feeders, whereas the diet of specimens from La Carolina Peninsula (Ecuador) was exclusively C4. The remaining South American groups analyzed were C3-C4 mixed-feeders. Carbon isotope composition of bone and teeth decreased as latitude increased. We found evidence of an exclusively C3-dominated diet at approximately 35–41°S. This result confirms that ancient feeding ecology cannot always be inferred from dental morphology or extant relatives. Data from middle and late Pleistocene indicated that, over time, there was an adaptive change in paleodiet from predominantly mixed-feeders to more specialized feeders. We propose that this dietary evolution was one of the causes that forced gomphotheres to extinction in South America. In addition, the data presented in this paper suggest that because of the different feeding preferences among mastodons, mammoths, and gomphotheres, only the bunodont gomphotheres reached South America.
This study is the first report on the mammalian fauna of the Quaternary of Serra da Bodoquena section, Mato Grosso do Sul, Brazil. We investigated three limestone caves for the occurrence of fossils: Nossa Senhora Aparecida, Japonês, and Nascente do Formoso, the two latter being underwater caves. For underwater caving, we developed an airlift system in order to collect small fossil fragments. We also attempted to retrieve specimens of the recent mammalian fauna. We recovered about 1650 fragments from the caves, and identified 74 species for the region (of which 34 are fossils). The paleontological results suggest that the Bodoquena region was probably characterized by an open savannah vegetation habitat rich in water patches.
The dispersal of Equus into South America during the Great American Biotic Interchange (GABI) represented a major event for Pleistocene land-mammal age chronology on that continent. It has been argued that this dispersal occurred during the late Pleistocene, ∼0.125 Ma, and it defines the base of the Lujanian South American Land Mammal Age (SALMA). In this scenario, Equus dispersed during the fourth and latest recognized phase of the interchange, i.e., GABI 4. Although Equus was widely distributed in South America during the Pleistocene, only a few localities are calibrated by independent chronostratigraphic data. In this paper, new biostratigraphic evidence documents that Equus occurs from 15 superposed faunal horizons or zones throughout the Tolomosa Formation at Tarija, Bolivia. This biostratigraphic sequence is independently calibrated to occur between ∼0.99 to <0.76 Ma during the middle Pleistocene Ensenadan SALMA and coincident with GABI 3, not GABI 4. Tarija remains the only well calibrated Ensenadan locality at which Equus is found. The new biostratigraphic data presented here are unambiguous and document the earlier (pre-Lujanian) occurrence of this genus in South America. The hypothesized dispersal of the genus Equus into South America at ∼0.125 Ma is no longer supportable in light of the new biostratigraphic evidence presented here. The new data from Tarija thus have continent-wide implications for the origins and biogeography of Equus in South America as well as the calibration of GABI 3.
Isotopic tracking of diet and habitat of European bison, Moose, and Aurochs since 12,000 years in Europe.
The analysis of stable isotope ratios represents one of the most exciting new technical advances in environmental sciences. In this book, leading experts offer the first survey of applications of stable isotope analysis to ecological research. Central topics are - plant physiology studies - food webs and animal metabolism - biogeochemical fluxes. Extensive coverage is given to natural isotopes of carbon, hydrogen, oxygen, nitrogen, sulfur, and strontium in both terrestrial and marine ecosystems. Ecologists of diverse research interests, as well as agronomists, anthropologists, and geochemists will value this overview for its wealth of information on theoretical background, experimental approaches, and technical design of studies utilizing stable isotope ratios.
The extinct megamammals Eremotherium laurillardi (weight 6550 kg), Notiomastodon platensis (w ¼ 6000 kg), Toxodon platensis (w ¼ 3090 kg), Valgipes bucklandi (w ¼ 980 kg) and Equus (Amerhippus) neogaeus (w ¼ 370 kg) are recorded for the late Pleistocene of the Brazilian Intertropical Region. In order to evaluate the isotopic paleoecology (feeding diet, niche breadth and overlap) of these species, 14 C dates, d 13 C and d 18 O analyzes were performed. Our results suggest that E. laurillardi (md 13 C ¼ À4.35 ± 2.87‰; mB A ¼ 0.77 ± 0.25), T. platensis (md 13 C ¼ À5.74 ± 4.80‰; mB A ¼ 0.57 ± 0.40) and N. platensis (md 13 C ¼ À1.17 ± 2.76‰; mB A ¼ 0.56 ± 0.20) were mixed feeders with a wide niche breadth, while E. (A.) neogaeus (md 13 C ¼ 0.73 ± 1.19‰; mB A ¼ 0.38 ± 0.22) was a grazer, and V. bucklandi (d 13 C ¼ À10.17‰; B A ¼ 0.13) was a specialist browser. A narrow niche overlap occurred between V. bucklandi and the species that fed principally on C 4 plants (>70%; O ¼ 0.24e0.43). In contrast, there was a high niche overlap between E. neogaeus and N. platensis (O ¼ 0.75) and between E. laurillardi and T. platensis (O ¼ 0.86). Therefore, E. laurillardi was probably a key species in this Pleistocene community due to its high body weight and wide niche breadth, suggesting that E. laurillardi was a great competitor for resources in the BIR.
The study of the radiocarbon age of bone bioapatite was initiated by necessity to date archaeological artifacts, which often contain little or no collagen as a result of poor preservation. Contamination of the organic fraction in the process of the burial or during museum preservation treatment generally prohibits the use of the collagen fraction for dating. Our investigation has shown that the pretreatment of bone with diluted acetic acid following a proscribed technique allows the separation of the bioapatite fraction from diagenetic carbonates. We have successfully used this technique to prepare and date samples of bone and of tooth enamel and dentin, with varying degrees of preservation condition, and from time intervals ranging from a few hundred 14 C yr to greater than 40,000 14 C yr.
Previously unreported fossil remains of mammalian carnivores from limestone caves of the State of Bahia were analyzed. Twelve species were identified: five felids, two canids, three mustelids, one ursid and a procyonid. Three of them are Pleistocenic and extinct, while the remaining probably dwelled in Late Pleistocene - Holocene.
Arctotherium angustidens Gervais and Ameghino, 1880 (the South American giant short-faced bear) is known for being the earliest (Ensenadan Age, early to middle Pleistocene) and largest (body mass over 1 ton) of five described Arctotherium species endemic to South America. Here we assess the diet of this bear from multiple proxies: morphology, biomechanics, dental pathology, stable isotopes and a previous study using geometric morphometric methodology. Results favor the idea of animal matter consumption, probably from large vertebrates in addition to vegetable matter consumption. Most probably, active hunting was not the unique strategy of this bear for feeding, since its large size and great power may have allowed him to fight for the prey hunted by other Pleistocene carnivores. However, scavenging over mega mammal carcasses was probably another frequent way of feeding. South American short-faced bears adjusted their size and modified their diet through Pleistocene times, probably as a response to the diversification of the carnivore guild (from the few precursory taxa that crossed the Panamanian Isthmus during the Great American Biotic Interchange).
A common use of stable isotope analysis in mammalogy is to make inferences about diet from isotope values (typically 13C and 15N) measured in tissues and food sources of a consumer. Mathematical mixing models are used to estimate the proportional contributions of food sources to the isotopic composition of the tissues of a consumer, which reflect the assimilated diet. This paper reviews basic mixing models and how they work; additional refinements also are described that include addressing uncertainty, larger numbers of sources, combining sources, concentration effects, and Bayesian statistical frameworks. Information is provided on where to access software for the various models. Numerous examples are cited to show application of these models in the mammal research literature.
Palynological studies in the Northern Andes have shown a gradual upheaval of the Cordillera during the Late Pliocene and the creation of the high montane environment. A long sequence of glacial and interglacial periods has been recorded from the Pleistocene. The successive appearance of new taxa, by evolutionary adaptation from the local neotropical flora and from elements immigrated from the holarctic and austral-antartic floral regions, can be followed step by step. For the Last Glacial to Holocene sequence the contemporaneity of the changes of temperature with those recorded from the northern temperate latitudes could be proved by 14 C dating During the coldest part of the Last Glacial the tree line descended to c. 2000 m altitude, i.e. 1200-1500 m lower than where it lies today. During the period from c. 21,000 to c. 13,000 B.P. the climate was, moreover much drier. Even taking the greater aridity into account, the lowering of the temperature during the coldest part of the Last Glacial may have been 6-7⚬ C or more. The lowering of the temperature in the tropical lowlands during glacial times may have been c. 3⚬ C. The temperature gradient must, therefore, have been steeper than it is today. In the coastal lowlands of Guyana and Surinam glacial-interglacial eustatic movements of sea level have been recorded. Pollen diagrams show in this area a considerable extension of savannas during glacial periods with low sea levels. In the inland savannas of the Llanos Orientales of Colombia and the Rupununi savanna of Guyana, several periods of grass-savanna and of savanna-woodland alternate during the Late Pleistocene and the Holocene; lower and higher lake levels corroborate the conclusions that these are caused by changes in the effective precipitation. One of the driest periods in the Rupununi seems to correspond to the time immediately before c. 13,000 B.P. Pollen data a series of samples from Rondonia, in the southern part of the Amazon basin, have shown that in that area grass-savannas replaced the tropical forest during a certain interval of Pleistocene age. From the above it appears that in considerable parts of the South American tropics a much drier climate prevailed during certain parts of the Pleistocene. A major dry period seems to have occurred during the later part of the Last Glacial, when the glaciers in the northern latitudes and in the Andes were reaching their maximum extension. These changes of climate and vegetation are of considerable importance for the explanation of speciation patterns and the recent distribution of plant and animal taxa.
Experiments that recorded the dispersal of 142 bones within a meandering, 2030 m-long reach of the East Fork River, Wyoming over a 13-year period provide a basis for interpreting distribution patterns and time averaging in fossiliferous channel deposits. Results show that light and porous bones, were transported farther than heavy bones. Bones became sorted by size and shape within 1 to 2 years and sorting patterns varied according to initial channel position. The combined distribution of bones from all the experimental sets, however, was unsorted and generally random.
Stable isotopes (δ13C, δ18O) in teeth of extinct mammals have been used as indicators of diets and climate conditions, which in turn are used for paleoenvironmental reconstructions. The first analysis of stable isotopes in Pleistocene mammals from Southern Brazil is reported here. The analyzed taxa were the notoungulate Toxodon and the proboscidean Stegomastodon from Late Middle to Late Pleistocene fossiliferous beds exposed along Chuí Creek, in the coastal plain of Rio Grande do Sul State. The δ13C isotopes indicate that Toxodon was a mixed-feeder that fed mostly on C4 plants, while Stegomastodon was a browser to mixed-feeder with preference for C3 plants, with less C4 plants in the diet compared to modern African elephants. Comparison with carbon isotopic values in fossils of these taxa from other Late Quaternary localities in South America shows an increased proportion of C3 plants in the diets of both Toxodon and Stegomastodon in higher latitudes. The values of δ18O in both taxa seem to reflect the isotopic composition of the ingested water rather than the isotopic content in the plants of which they fed on, and the observed variations are likely to mirror variations of the patterns of precipitation. Paleoclimatic inferences and possible causes for the (pseudo)extinction of these taxa in southern Brazil are also discussed.
Geochemical tools, including the analysis of stable isotopes from fossil mammals, are often used to infer regional climatic and environmental differences. We have further developed an oxygen isotope aridity index and used oxygen (δ18O) isotope values and carbon (δ13C) isotope values to assess regional climatic differences between the southeastern and southwestern United States during the Pleistocene. Using data collected from previously published studies, we assigned taxa to evaporation-sensitivity categories by quantifying the frequency and magnitude of aridity index values (i.e., an average taxon δ18O value minus a site specific proboscidean δ18O value). Antilocapridae, Camelidae, Equidae, and Cervidae were identified as evaporation-sensitive families, meaning that a majority of their water comes from the food they eat, thus indicating that they are more likely to capture changing climatic conditions. Bovidae, Tayassuidae, and Tapiridae were identified as less sensitive families, possibly because of increased or more variable drinking behavior. While it is difficult to tease out individual influences on δ18O values in tooth enamel, the use of an aridity index will provide a more in-depth look at relative aridity in the fossil record. Greater aridity index values in the Southwest suggest a drier climate than in the Southeast during the Pleistocene, and δ13C values suggest that diet does not determine evaporation sensitivity. The combination of more-positive δ13C values and the lack of forest indicator taxa in the Southwest suggest that landscapes were more open than in the Southeast. Inferred higher aridity in the Southwest may indicate that aridity or seasonal aridity/precipitation, not temperature or pCO2, was a greater driver of C4 abundance during the Pleistocene. Collectively, these data suggest that regional climatic and environmental interpretations can be improved by using an aridity index and a more detailed understanding of mammalian paleobiology.
The applicability of rapid and precise laser probe analysis of tooth enamel for {delta}{sup 18}O has been verified, and the method has been applied to different modern herbivores in East Africa. Sampling and pretreatment procedures involve initial bleaching and grinding of enamel to <75 {mu}m, and elimination of adsorbed water and organic compounds with BrF{sub 5}. Typical analytical reproducibilities for 0.5-2 mg samples are {+-}0.08{per_thousand} ({+-} 1{sigma}). Chemical and spectroscopic characterization of pretreated but unanalyzed samples show no alteration compared to fresh enamel. Solid reaction products are nearly pure CaF{sub 2} with little evidence for residual O{sub 2}. Because laser probe fluorination extracts oxygen from all sites in the apatite structure (phosphate, structural carbonate, and hydroxyl), only unaltered tooth enamel ( >95% apatite) can be analyzed reliably. Different East African herbivores exhibit previously unsuspected compositional differences. Average enamel {delta}{sup 18}O values (V-SMOW) are approximately: 25{per_thousand} (goat). 27{per_thousand} (oryx), 28{per_thousand} (dikdik and zebra), 29{per_thousand} (topi), 30{per_thousand} (gerenuk), and 32{per_thousand} (gazelle). These compositions differ from generalized theoretical models, but are broadly consistent with expected isotope effects associated with differences in how much each animal (a) drinks, (b) eats C3 vs. C4 plants, and (c) pants vs. sweats. Consideration of diet, water turnover. and animal physiology will allow the most accurate interpretation of ancient teeth and targeting of environmentally-sensitive animals in paleoclimate studies. 66 refs., 2 figs., 2 tabs.
Since 2001, the Center for Applied Isotope Studies at the University of Georgia has analyzed more than 10,000 samples using a compact AMS system for carbon isotope measurement. The system, manufactured by National Electrostatics Corporation, utilizes a Model 1.5SDH-1 Pelletron accelerator with a maximum terminal voltage of 0.5 MV. The source has recently been modified, doubling the count rate and improving efficiency more than 50%. Background values have reached 0.12 pMC and the precision is below 0.4 pMC for modern samples. The control and data acquisition system has also been upgraded.
The carbonate caves of the Upper Ribeira Valley, southeastern São Paulo State, Brazil, preserve an abundant fossil record of Pleistocene-Holocene South American megafauna. Nevertheless, in comparison with other localities of the country, its paleontological knowledge still can be considered sparse and in need of further research. This work presents an update taxonomic survey of the megafauna material collected since the beginning of the explorations in the area. Based on this, it discusses paleobiogeographic and paleoecological questions. The fossil megafauna of the Upper Ribeira karst region include: Eremotherium laurillardi, Nothrotherium maquinense, Lestodon armatus, Catonyx cuvieri, ‘Ocnopus gracilis’, Ahytherium aff. aureum, Glyptodon clavipes, G. reticulatus, Hoplophorus cf., Toxodon spp., Stegomastodon waringi, Equidae (Hippidion cf.), Tapirus terrestris, Panthera onca and Smilodon populator. Only P. onca and T. terrestris still remain in the region. Despite the occurrence of some typical taxa of the pampean paleobiogeographical province, the fossil assemblage recorded shows greater affinity to the mega-mammal community of the intertropical region. The ecology of species found suggests the previous occurrence of fairly different environmental settings than the existing one in the area. There were more temperate climates – both dry and wet – until the current mesophytic forest was finally established. The studied material does not show any kind of chrono-correlation, given the type of genesis of the cave accumulations. These fossils depict different faunistic moments related to climate changes during the Quaternary. To better understand the information provided by these deposits, efforts on dating and detailed taphonomic investigations should be conducted. The studies of the Quaternary fauna in the state of São Paulo fill an important gap in the intricate biogeographical history of the South American megafauna.
The South American gomphotheres were previously classified in three genera and three species. Two biogeographic corridors are recognized for the dispersion of gomphotheres in South America. Cuvieronius hyodon was found mainly in the highlands and west to the Andes, and Stegomastodon platensis and Haplomastodon chimborazi were found in lowlands. The aim of the present study is to review the taxonomy of South American lowland gomphotheres. A large sample of specimens was analyzed, which included crania, teeth and postcrania from several localities in Brazil, Ecuador, Colombia, Venezuela, Argentina, and Uruguay. A review of the diagnostic characters proposed in previous taxonomic studies of South American lowland gomphotheres found that they are variable in both reputed species if large samples are considered. There is no support for more than one South American lowland gomphothere species, and it shows a significant morphological variation in some characteristics. The name for this taxon, after a taxonomic review, must be Notiomastodon platensis (Ameghino, 1888) new combination. This reduces the number of gomphothere species in South America to two genera and species. The lowland gomphothere is closely related to Cuvieronius and Rhynchotherium, and not closely related to Stegomastodon from North America, and Sinomastodon from Asia.
a b s t r a c t In South America, one of the most important themes is the effort to discover the diet of the extinct giant mammals that lived in this continent. This paper presents new data for the species Palaeolama major, acquired by the analysis of plant fragments found in coprolites. This species possibly lived in an open area, feeding on shrubs, in the forest border.
During the Pleistocene a fauna composed of large (biomass>44 kg) and giant mammals (biomass>1000 kg) that are usually associated with open environments lived in the Brazilian Intertropical Region. We present here new information concerning the paleoecology and chronology of some species of this megafauna. Carbon isotope analyses were performed for a better understanding of the paleoecology of the species Eremotherium laurillardi (Lund, 1842), Notiomastodon platensis (Ameghino, 1888) and Toxodon platensis (Owen, 1849). The δ 13 C data allow attributing a generalist diet to these species, which varied according to the kind of habitat in which they lived. In more open habitats all species were grazers; in mixed habitats E. laurillardi and T. platensis were mixed feeders, and N. platensis was grazer; and in more closed habitats all species were mixed feeders.
When the Panamanian land bridge was emplaced about 2.7 Ma, it triggered the Great American Biotic Interchange (GABI), a major mingling of land mammal faunas between North and South America. Four families of northern immigrants (Procyonidae, Felidae, Tayassuidae, and Camelidae) diversified at moderate rates, while four others, Canidae, Mustelidae, Cervidae, and especially Muridae, evolved explosively. As a consequence, half of living South American genera are descendants of northern immigrants. The other major consequence of the interchange was the conquest of tropical North America by immigrants from Amazonia, an episode that justifies the term Neotropical Realm.
