02587nas a2200205 4500008004100000245013300041210006900174300001200243490000700255520190300262653001202165653001702177653001702194653001702211653001402228100001802242700002002260700001802280856008302298 2017 eng d00aTrace Element Analysis Provides Insight into the Diets of Early Late Miocene Ungulates from the Rudabánya II Locality (Hungary)0 aTrace Element Analysis Provides Insight into the Diets of Early a231-2430 v153 a
The early Late Miocene vertebrate locality of Rudabánya II (R. II) in northeastern Hungary preserves an abundance of forest-adapted ungulate species. To better understand the ecological relationships within this ancient ecosystem, we used analysis of enamel strontium/calcium (Sr/Ca) ratios to infer dietary preferences. The goals of the analysis were to: i) determine whether these ungulate species specialized in specific plants or plant parts; ii) discern whether the Sr/Ca ratios support what was previously suggested about the ecology of these species; and iii) evaluate the factors that may have acted to promote coexistence within this diverse community of predominantly browsing herbivores. Results show significant differences in the diets of the sampled species. The highest Sr/Ca ratios were displayed by the suids Parachleuastochoerus kretzoii [B1] and Propotamochoerus palaeochoerus implying a preference for Sr-rich underground plant parts. Elevated Sr/Ca ratios yielded by the cervid Lucentia aff. pierensis and equid Hippotherium intrans are indicative of intermediate feeding. The bovid Miotragocerus sp. showed higher Sr/Ca ratios than the gomphothere Tetralophodon longirostris, which is incongruent with morphological and stable isotope data, and suggested browsing by both taxa. This finding is likely the result of a difference in digestive physiology (ruminant vs. monogastric) rather than a difference in dietary behaviour. The lowest Sr/Ca ratios were displayed by the traguild Dorcatherium naui and moschid Micromeryx flourensianussuggesting a preference for Sr-poor fruits. Resource specialization and partitioning within the local environment likely acted to decrease interspecific competition and promote coexistence within the diverse ungulate community at R. II.
10aHungary10aLate Miocene10apaleoecology10aSr/Ca ratios10aUngulates1 aEastham, L.C.1 aFeranec, R., S.1 aBegun, D., R. uhttp://revistes.ub.edu/index.php/GEOACTA/article/view/GeologicaActa2017.15.3.602875nas a2200205 4500008004100000245011100041210006900152300001000221490000800231520224900239653002202488653001502510653002002525653001202545653001202557653001402569100002002583700001502603856005102618 2013 eng d00aStable Carbon Isotope Evidence for the Abundance of C4 Plants in the Middle Miocene of Southern California0 aStable Carbon Isotope Evidence for the Abundance of C4 Plants in a42-470 v3883 aThe abrupt spread of grasslands using C4 photosynthesis, sometimes referred to as the rapid increase in C4 ecosystems (RICE), occurred in the late Miocene in North America. While fossil plant specimens from the Miocene Dove Spring Formation of California as well as data from phylogenetic studies and molecular clocks show that C4 grasses evolved prior to the RICE, most isotopic data from paleosols and mammal tooth enamel suggest that its abundance on the landscape was minimal. However, a few recent studies from the Great Plains suggest that C4 grasslands may have been more prominent prior to the RICE event. Here we examine stable carbon isotope values from ungulate tooth enamel from the Barstow Formation of southern California, which is geographically and temporally close to the Dove Spring Formation, and records a diverse and abundant paleofauna of medial Miocene age. Tooth enamel δ13C values were examined in seven ungulate genera including the hypsodont equids; Acritohippus sp. and Scaphohippus sp.; the camelids, Aepycamelus sp., Hesperocamelus sp., and Procamelus sp.; the antilocaprid, Merycodus sp.; and the proboscidean, Gomphotherium sp. More positive δ13C values observed within the equids, camelids, and antilocaprids are suggestive of C4 grasses being included in the diets of these taxa. The equids exhibited the most positive mean δ13C values, which indicate a higher component of dietary C4 grasses (up to 18%) when compared to the other sampled ungulate taxa. The tooth enamel isotope values presented in this study show the presence of C4 grasses as a significant component of ungulate diets millions of years before the RICE. The abundance of C4 plants earlier in the Miocene may imply a more significant role in the major ungulate diversification events than previously suspected. The few pre-RICE localities showing evidence of C4 abundance suggests that these grasslands were geographically restricted which limits, but may not exclude, the possibility that a world-wide mechanism controlled its spread.
10aBarstow Formation10aC4 grasses10aCarbon isotopes10aEquidae10aMiocene10aUngulates1 aFeranec, R., S.1 aPagnac, D. uhttp://dx.doi.org/10.1016/j.palaeo.2013.07.022