A paleontological deposit near San Clemente de Térapa represents one of the very few Rancholabrean North American Land Mammal Age sites within Sonora, Mexico. During that time, grasslands were common, and the climate included cooler and drier summers and wetter winters than currently experienced in northern Mexico. Here, we demonstrate restructuring in the mammalian community associated with environmental change over the past 40,000 years at Térapa. The fossil community has a similar number of carnivores and herbivores whereas the modern community consists mostly of carnivores. There was also a 97% decrease in mean body size (from 289 kg to 9 kg) because of the loss of megafauna. We further provide an updated review of ungulates and carnivores, recognizing two distinct morphotypes of Equus, including E. scotti and a slighter species; as well as Platygonus compressus; Camelops hesternus; Canis dirus; and Lynx rufus; and the first regional records of Palaeolama mirifica, Procyon lotor, and Smilodon cf. S. fatalis. The Térapa mammals presented here provide a more comprehensive understanding of the faunal community restructuring that occurred in northern Mexico from the late Pleistocene to present day, indicating further potential biodiversity loss with continued warming and drying of the region.

中文翻译：

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墨西哥索诺拉晚更新世大型哺乳动物群落的古生物学

San Clemente de Térapa 附近的一个古生物矿床是墨西哥索诺拉境内为数不多的 Rancholabrean 北美陆地哺乳动物时代遗址之一。在那段时间，草原很常见，气候包括比墨西哥北部目前经历的更凉爽干燥的夏季和更潮湿的冬季。在这里，我们展示了与过去 40,000 年在 Térapa 的环境变化相关的哺乳动物群落的重组。化石群落的食肉动物和食草动物数量相似，而现代群落主要由食肉动物组成。由于巨型动物的丧失，平均体型也减少了 97%（从 289 公斤到 9 公斤）。我们进一步提供了对有蹄类动物和食肉动物的更新评论，认识到两种不同的形态类型马， 包含乙.斯科蒂和一个较小的物种；也扁柏;骆驼;大犬; 和猞猁；和第一个区域记录苦瓜,南河豚， 和剑齿虎参看。小号.致命的. 这里介绍的 Térapa 哺乳动物提供了对墨西哥北部从晚更新世至今的动物群落重组的更全面的了解，表明随着该地区持续变暖和干燥，生物多样性可能进一步丧失。