Within the subfamily Scelidotheriinae, Valgipes bucklandi represents one of the least known taxa due to its scarce records and material found so far. This Pleistocene ground sloth had been registered only in Brazil, within the Brazilian Intertropical Region (BIR) in the states of Bahia, Minas Gerais, Piauí, Rio Grande do Norte and, more recently, outside the BIR, in Mato Grosso do Sul. A particular feature of this sloth is the proximal and distal fusion of the tibia and fibula in adults. Here, we report a tibia-fibula assigned to V. bucklandi found in Arroyo del Vizcaíno (Canelones, Uruguay), a fossiliferous site that harbors a large amount of megamammal remains at an approximate age of 30 ka (29696–32009 cal yr B.P.). We performed stable isotopes analyses and ecological niche models (ENM) to study V. bucklandi distribution and climatic and dietary preferences, as well as to better understand its presence ∼2000 km southward of its previous recorded occurrences. δ¹³C values were consistent with those of the BIR, indicating a similar preference for C₃ plants, while the results of δ¹⁸O values could be related to colder and more humid environments, clearly different from those obtained from BIR specimens. Furthermore, the ENM results also showed colder and more humid environments for the AdV record, with the occurrence being in the margins of the predicted potential distribution of the taxa. This discovery expands the distribution of this taxa to southern colder climates, indicating a greater climatic tolerance. Moreover, our results support the existence of mixed faunas composed of Southern and Northern taxa coexisting in Southern Uruguay at the onset of the Last Glacial Maximum, and provide evidence of the existence of an open mosaic habitat with patches of mixed vegetation in the region.

在 Scelidotheriinae 亚科中，由于迄今为止发现的记录和材料稀少，Valgipes bucklandi是最不为人知的分类群之一。这种更新世地懒仅在巴西的巴伊亚州、米纳斯吉拉斯州、皮奥伊州、北里奥格兰德州的巴西热带地区 (BIR) 内以及最近在 BIR 以外的南马托格罗索州注册。这种树懒的一个特殊特征是成人胫骨和腓骨的近端和远端融合。在这里，我们报告了分配给V. bucklandi的胫腓骨发现于 Arroyo del Vizcaíno（乌拉圭卡内洛内斯），这是一个化石遗址，拥有大量大约 30 ka（29696-32009 cal yr BP）的巨型哺乳动物遗骸。我们进行稳定同位素分析和生态位模型（ENM）研究V. bucklandi分布，气候和饮食偏好，以及更好地了解以前的记录出现它的身影〜2000公里向南。δ ¹³ C 值与 BIR 一致，表明对 C ₃植物的偏好相似，而 δ ¹⁸的结果O 值可能与更冷和更潮湿的环境有关，明显不同于从 BIR 样本中获得的值。此外，ENM 结果还显示 AdV 记录的环境更冷、更潮湿，发生在分类群预测潜在分布的边缘。这一发现将这一类群的分布扩展到南部较冷的气候，表明其具有更大的气候耐受性。此外，我们的结果支持在末次盛冰期开始时在乌拉圭南部共存由南部和北部分类群组成的混合动物群，并提供证据表明该地区存在具有混合植被斑块的开放镶嵌栖息地。