02619nas a2200289 4500008004100000022001300041245006600054210006500120300000800185490000700193520182900200653001402029653002102043653002002064653001002084653001202094653001402106653001602120653001302136653001502149653002002164100002102184700002002205700001502225700002202240856006702262 2021 eng d a0960982200aDietary ecology of the scimitar-toothed cat Homotherium serum0 aDietary ecology of the scimitartoothed cat Homotherium serum a1-80 v313 a

The scimitar-toothed cat Homotherium was one of the most cosmopolitan cats of the Pleistocene, present throughout Eurasia, Africa, and the Americas until at least ~28 thousand years ago. Friesenhahn Cave (Bexar County, Texas) contains some of the best-preserved specimens of Homotherium serum alongside an abundance of juvenile mammoths, leading some to argue that H. serum preferentially hunted juvenile mammoths.Dietary data of Homotherium are rare, with their ecology inferred from morphological, taphonomic, and genetic data. Here, we use a multi-proxy approach to clarify the dietary ecology of H. serum as compared to extinct and extant cats and their relatives. Dental microwear texture analysis (DMTA) reveals that H. serum consumed soft and tough foods, similar to the extant cheetah, which actively avoids bone, but in stark contrast to extant lions and hyenas, which are observed to engage in durophagy (i.e., bone processing). DMTA data are consistent with taphonomic evidence of bone defleshing and the absence of bone-crunching behavior in H. serum. Stable carbon isotope values of H. serum indicate a clear preference for C4 grazers including juvenile mammoths, in agreement with taphonomic evidence suggestive of a Homotherium den and morphological data indicative of a relatively cursorial lifestyle. Notably, the inferred diet of H. serum contrasts with the extinct dirk-tooth sabertooth cat Smilodon fatalis, which preferred forest/woodland prey and engaged in bone processing. Homotherium serum exhibited a novel combination of morphological adaptations for acquiring open-country prey, consuming their soft and tough flesh—including the tough flesh of juvenile mammoths.

10acarnivore10adental microwear10adietary ecology10afelid10amammoth10aMammuthus10aPleistocene10aPredator10asabertooth10aStable isotopes1 aDeSantis, L.R.G.1 aFeranec, R., S.1 aAntón, M.1 aLundelius, E., L. uhttps://linkinghub.elsevier.com/retrieve/pii/S096098222100434602682nas a2200349 4500008004100000022001300041245010600054210006900160260001200229300001900241490000700260520164700267653001001914653001401924653002101938653000901959653001201968653001701980653001601997653001902013653001302032653002002045100002702065700002502092700002002117700002002137700002502157700002102182700002302203700002302226856008302249 2019 eng d a0960982200aCauses and Consequences of Pleistocene Megafaunal Extinctions as Revealed from Rancho La Brea Mammals0 aCauses and Consequences of Pleistocene Megafaunal Extinctions as c08/2019 a2488 - 2495.e20 v293 a

The fossils preserved in the Rancho La Brea “tar” seeps in southern California span the past ∼50,000 years and provide a rare opportunity to assess the ecology of predators (e.g., the American lion, sabertooth cats, cougars, dire wolves, gray wolves, and coyotes), including clarifying the causes and consequences of the terminal Pleistocene extinction event. Here, a multi-proxy approach elucidates dietary responses of carnivorans to changing climates and megafaunal extinctions. Using sample sizes that are unavailable anywhere else in the world, including hundreds of carnivoran and herbivore specimens, we clarify the paleobiology of the extinct sabertooth cats and dire wolves—overturning the idea that they heavily competed for similar prey. Canids (especially the dire wolf) consumed prey from more open environments than felids, demonstrating minimal competition for prey throughout the latest Pleistocene and largely irrespective of changing climates, including just prior to their extinction. Coyotes experienced a dramatic shift in dietary behavior toward increased carcass utilization and the consumption of forest resources (prey and/or plant resources) after the terminal Pleistocene megafaunal extinction. Extant predators’ ability to effectively hunt smaller prey and/or utilize carcasses may have been a key to their survival, especially after a significant reduction in megafaunal prey resources. Collectively, these data suggest that dietary niches of carnivorans are not always static and can instead be substantially affected by the removal of top predators and abundant prey resources.

10aCanis10aCarnivora10adental microwear10aDiet10amammals10apaleoecology10aPleistocene10aRancho La Brea10aSmilodon10aStable isotopes1 aDeSantis, Larisa, R.G.1 aCrites, Jonathan, M.1 aFeranec, R., S.1 aFox-Dobbs, Kena1 aFarrell, Aisling, B.1 aHarris, John, M.1 aTakeuchi, Gary, T.1 aCerling, Thure, E. uhttps://www.sciencedirect.com/science/article/pii/S0960982219307869?via%3Dihub03112nas a2200313 4500008004100000022001400041245011200055210006900167260001200236490000800248520214700256653002402403653001702427653001802444653001302462653002202475653002402497653001902521653001602540653001502556653001902571100002602590700001602616700001802632700002202650700002502672700002102697856008002718 2019 eng d a0004-803800aGenetic structure and biogeographic history of the Bicknell’s Thrush/ Gray-cheeked Thrush species complex0 aGenetic structure and biogeographic history of the Bicknell s Th c11/20190 v1373 a

We examined species limits, admixture, and genetic structure among populations in the Bicknell’s Thrush (Catharus bicknelli)–Gray-cheeked Thrush (C. minimus) species complex to establish the geographic and temporal context of speciation in this group, which is a model system in ecology and a high conservation priority. We obtained mitochondrial ND2 sequences from 186 Bicknell’s Thrushes, 77 Gray-cheeked Thrushes, and 55 individuals of their closest relative, the Veery (C. fuscescens), and genotyped a subset of individuals (n = 72) at 5,633 anonymous single nucleotide polymorphic (SNP) loci. Between-species sequence divergence was an order of magnitude greater than divergence within each species, divergence was dated to the late Pleistocene (420 kbp) based on Bayesian coalescence estimation, and a coalescent model (IMa) revealed almost no gene flow between species based on ND2. SNP data were consistent with mitochondrial results and revealed low levels of admixture among species (3 of 37 Bicknell’s Thrushes, no Gray-cheeked Thrushes, and no Veeries were >2% admixed). Species distribution models projected to the Last Glacial Maximum suggest that Bicknell’s Thrush and Gray-cheeked Thrush resided in primarily allopatric refugia in the late Pleistocene, consistent with the genetic data that support reproductive isolation over an extended period of time. Our genetic data suggest that both species underwent demographic expansions, possibly as they expanded out of Pleistocene refugia into their current ranges. We conclude that Bicknell’s Thrush and Gray-cheeked Thrush are 2 distinct species-level lineages despite low levels of Gray-cheeked Thrush introgression in Bicknell’s Thrushes, and divergence has been maintained by a long history of allopatry in subtly different habitats. Their unique phylogeography among boreal forest birds indicates that either cryptic species breaks in eastern North America are still undiscovered, or another factor, such as divergent natural selection, high migratory connectivity, or interspecific competition, played a role in their divergence.

10aBicknell’s Thrush10aBiogeography10aboreal forest10aCatharus10agenetic structure10aGray-cheeked Thrush10aphylogeography10aPleistocene10aSpeciation10aspecies limits1 aFitzgerald, Alyssa, M1 aWeir, Jason1 aRalston, Joel1 aWarkentin, Ian, G1 aWhitaker, Darroch, M1 aKirchman, J., J. uhttps://academic.oup.com/auk/advance-article/doi/10.1093/auk/ukz066/564818801444nas a2200193 4500008004100000245009800041210006900139300001200208490000700220520085200227653001101079653001401090653001301104653001601117653002301133100002001156700002201176856005201198 2012 eng d00aNew AMS Radiocarbon Dates from Late Pleistocene Mastodons and Mammoths in New York State, USA0 aNew AMS Radiocarbon Dates from Late Pleistocene Mastodons and Ma a275-2790 v543 a

During the Last Glacial Maximum (LGM) about 25,000 yr ago, the area of what is now New York State (USA) was almost entirely covered by the Laurentide Ice Sheet (LIS; Dyke et al. 2002). Subsequent habitation of this area after the melting of the LIS necessitates dispersal of fauna, and the timing of the dispersal of particular species may aid in the understanding of how the modern ecosystems of New York were assembled. Mastodons and mammoths represent the most abundant post-LGM Pleistocene megafauna recovered in New York. However, many of the specimens have not been dated. This paper presents a set of dates from bone and tooth dentine collagen of late Pleistocene mastodon (n = 7) and mammoth (n = 3) specimens housed in the Vertebrate Paleontology Collections at the New York State Museum, Albany, New York, USA.

10aMammal10aMegafauna10aNew York10aPleistocene10aRariocarbon dating1 aFeranec, R., S.1 aKozlowski, A., L. uhttp://dx.doi.org/10.2458/azu_js_rc.v54i2.1600902989nas a2200229 4500008004100000245014700041210006900188300001200257490000800269520229300277653000902570653000902579653001202588653001102600653000902611653001602620100002002636700001502656700001702671700002002688856005102708 2010 eng d00aUnderstanding the Ecology of Mammalian Carnivorans and Herbivores from Valdegoba Cave (Burgos, Northern Spain) Through Stable Isotope Analysis0 aUnderstanding the Ecology of Mammalian Carnivorans and Herbivore a263-2720 v2973 a

Stable carbon and oxygen isotope analyses of mammalian carnivoran and herbivore species from the late Pleistocene Valdegoba cave site in northern Spain imply competition and partitioning in resource use. In general, the data support the previously recognized ecology for the analyzed species. δ13C values show that the ecosystem around the cave was dominated by C3 plants. The observed δ18O values are similar to what is found in modern environments. The analyzed bovids, Bos primigenius, Capra pyrenaica, and Rupicapra rupicapra, showed the most positive δ13C values. Bos primigenius had the most positive mean carbon isotope value and is suggested to feed on grasses in open environments. Values for Capra pyrenaica primarily indicate grass feeding, while Rupicapra rupicapra had the widest diet for the analyzed species, likely including grass and browse. Cervus elaphus, Equus ferus, Equus hydruntinus, and Stephanorhinus hemitoechus displayed more negative δ13C values indicating the use of similar resources. The smallest species analyzed, Castor fiber, displayed the most negative δ13C and δ18O values, implying a preference for eating C3 plants and being semi-aquatic. The canids, Canis lupus and Vulpes vulpes, displayed the most positive δ13C and δ18O values, and overlap many of the sampled ungulate species. Positive δ18O values in canids implies that this group obtains much of its water from its prey, uses a different water source, or has physiological differences from the other carnivorans that influence oxygen isotope values. Lynx pardinus had values similar to the canids. Crocuta crocuta had δ13C values more negative than expected for a generalist predator. These values are likely due to concentration of diet on taxa from more forested environments. The most negative δ13C values are observed in the bears, Ursus arctos and Ursus spelaeus. These values are the likely result of hibernation and the inclusion of significant vegetation in bear diets.

10aC-1310aDiet10aEcology10aMammal10aO-1810aPleistocene1 aFeranec, R., S.1 aGarcia, N.1 aDiez, J., C.1 aArsuaga, J., L. uhttp://dx.doi.org/10.1016/j.palaeo.2010.08.00602287nas a2200193 4500008004100000245008600041210006900127300003700196490000600233520163500239653001901874653001601893653001301909653002801922100002401950700002001974700002201994856007702016 2009 eng d00aEffects of Global Warming on Ancient Mammalian Communities and Their Environments0 aEffects of Global Warming on Ancient Mammalian Communities and T ae5750. doi:10.1371/journal.pone.0 v43 a

Background

Current global warming affects the composition and dynamics of mammalian communities and can increase extinction risk; however, long-term effects of warming on mammals are less understood. Dietary reconstructions inferred from stable isotopes of fossil herbivorous mammalian tooth enamel document environmental and climatic changes in ancient ecosystems, including C3/C4 transitions and relative seasonality.

Methodology/Principal Findings

Here, we use stable carbon and oxygen isotopes preserved in fossil teeth to document the magnitude of mammalian dietary shifts and ancient floral change during geologically documented glacial and interglacial periods during the Pliocene (~1.9 million years ago) and Pleistocene (~1.3 million years ago) in Florida. Stable isotope data demonstrate increased aridity, increased C4 grass consumption, inter-faunal dietary partitioning, increased isotopic niche breadth of mixed feeders, niche partitioning of phylogenetically similar taxa, and differences in relative seasonality with warming.

Conclusion/Significance

Our data show that global warming resulted in dramatic vegetation and dietary changes even at lower latitudes (~28°N). Our results also question the use of models that predict the long term decline and extinction of species based on the assumption that niches are conserved over time. These findings have immediate relevance to clarifying possible biotic responses to current global warming in modern ecosystems.

10aglobal warming10aPleistocene10aPliocene10astable isotope analysis1 aDeSantis, L., R. G.1 aFeranec, R., S.1 aMacFadden, B., J. uhttp://journals.plos.org/plosone/article?id=10.1371/journal.pone.000575002445nas a2200253 4500008004100000245014600041210006900187300001400256490000700270520168600277653000901963653000901972653001201981653001101993653001102004653000902015653001602024100001502040700002002055700002002075700003002095700001802125856004802143 2009 eng d00aIsotopic Analysis of the Ecology of Herbivores and Carnivores from the Middle Pleistocene Deposits of the Sierra de Atapuerca, Northern Spain0 aIsotopic Analysis of the Ecology of Herbivores and Carnivores fr a1142-11510 v363 a

Carbon and oxygen isotope values reveal resource partitioning among the large mammal fauna from three contemporaneous Middle Pleistocene hominid-bearing localities within the Sierra de Atapuerca (northern Spain). Carbon isotope values sampled from the tooth enamel of fauna present during Atapuerca Faunal Unit 6 show that a C3-dominated ecosystem surrounded the area where fossils were preserved during this time. For the herbivores, Fallow deer isotope values are significantly different from Red deer and horses and show that this species did not forage in open environments at this locality. Red deer and horses show similar feeding strategies with less negative carbon values implying use of more open environments for these taxa. For the carnivores, carbon isotope values for Ursus deningeri are significantly different from either lions (Panthera leo) or foxes (Vulpes vulpes) and support the contention that this species is herbivorous. Special metabolic mechanisms involved in hibernation in U. deningeri might also have influenced its isotope values. The carbon isotope values of remaining carnivores were similar and suggest that each was typically a generalist carnivore, eating a wide variety of prey items. While the isotopic results generally correspond to ecology indicated by previous techniques, this study shows that isotope analyses can provide further insights that alternate techniques do not provide. Isotope analyses can help elucidate the ancient ecology of taxa present in the Sierra de Atapuerca during the Middle Pleistocene allowing for an accurate portrayal of the setting in which humans lived.

10aC-1310aDiet10aEcology10aEnamel10aMammal10aO-1810aPleistocene1 aGarcia, N.1 aFeranec, R., S.1 aArsuaga, J., L.1 ade Castro, J., M. Bermude1 aCarbonell, C. uhttp://dx.doi.org/10.1016/j.jas.2008.12.018