ABSTRACT

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 δ¹³C and δ¹⁸O 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.

摘要

牙釉质、牙本质和骨羟基磷灰石中的稳定同位素是调查已灭绝生物古生态学的重要工具，可用作不同环境参数（例如饮食、温度、行会）的替代物，有助于重建过去的环境。来自巴西热带地区几个地方的晚更新世Toxodon platensis、Eremotherium laurillardi、Notiomastodon platensis、Glyptotherium sp.、Hippidion principale、Xenorhinotherium bahiense和Nothrotherium maquinense 的牙齿和骨骼样本具有δ ¹³ C 和δ ¹⁸O 进行分析以推断他们的古生物、行会和生态位广度，从而可以重建他们过去生活的环境。包括马同位素数据雅科仕（Amerhippus）neogeus，巨喇嘛Palaeolama主要的Cingulatas Panochthus SP。和Holmesina paulacoutoi，以及巨型地懒Valgipes bucklandi，我们可以认为巴西热带地区出现了三个行会：浏览器（N. maquinense、V. bucklandi、X. bahiense）、混合饲养者（H. principale、E. larillardi , T. platensis, N. platensis, P. major, Panochthus sp., H. paulacoutoi) 和食草动物 ( E. ( A. ) neogeus, Glyptotherium sp.)。这些结果表明一个干燥的环境，混合植被和开阔的稀树草原占主导地位，这表明当时的地区与目前更干旱和开阔的灌木稀树草原地区相似。