Dental and craniomandibular data have been predominantly used to infer relationships among mylodontid ground sloths. Recent studies indicate the osteology of the manus also provides useful data to test phylogenetic relationships in mylodontine mylodontids. Here we provide new comparative data from the study of the manus of a member of the Scelidotheriinae, Scelidotherium Owen, 1839, based on specimens from the Province of Cordoba that provide information on the variation and systematic relationships of the genus. The Scelidotherium material from the Province of Cordoba in central Argentina presents several morphological differences with material of the genus from northwestern Argentina. The manus of Scelidotherium shares several traits with Catonyx Ameghino, 1891, but not with Valgipes Gervais, 1874. These include: trapezoid with a sharp ridge on the articular surface for metacarpal II; magnum with at least half of articular surface for metacarpal II located on the dorsal half of the medial and distal aspects of the bone; metacarpal II with a notch on the axial border of its distal articular surface; and ungual process of the distal phalanx of the second digit markedly dorsopalmarly flattened. A phylogenetic analysis that includes osteological characters of the manus indicates that within the family Scelidotheriinae, Scelidotherium is more closely related to Catonyx than to Valgipes or Proscelidodon gracillimus Rovereto, 1914.

中文翻译：

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来自阿根廷科尔多瓦省更新世的 Scelidotherium (Xenarthra, Mylodontidae) 标本的骨骼及其系统意义

牙齿和颅下颌数据主要用于推断 mylodontid 地懒之间的关系。最近的研究表明，manus 的骨学也提供了有用的数据来测试 mylodontine mylodontids 的系统发育关系。在这里，我们根据科尔多瓦省的标本提供了对 Scelidotheriinae 成员 Scelidotherium Owen 的手部研究的新比较数据，该标本提供了有关该属变异和系统关系的信息。来自阿根廷中部科尔多瓦省的 Scelidotherium 材料与来自阿根廷西北部的该属的材料在形态上存在一些差异。Scelidotherium 的手部与 Catonyx Ameghino（1891 年）有几个特征，但与 Valgipes Gervais（1874 年）不同。其中包括：梯形，在第二掌骨的关节面上有一个尖锐的脊；II 掌骨的关节面至少有一半位于骨的内侧和远侧的背侧；II掌骨在其远端关节面的轴向边缘上有一个凹口；和第二指的远节指骨的甲突明显背掌变平。包括手足骨学特征的系统发育分析表明，在 Scelidotheriinae 家族中，Scelidotherium 与 Catonyx 的关系比与 Valgipes 或 Proscelidodon gracillimus Rovereto 的亲缘关系更密切，1914 年。II掌骨在其远端关节面的轴向边缘上有一个凹口；和第二指的远节指骨的甲突明显背掌变平。包括手足骨学特征的系统发育分析表明，在 Scelidotheriinae 家族中，Scelidotherium 与 Catonyx 的关系比与 Valgipes 或 Proscelidodon gracillimus Rovereto 的亲缘关系更密切，1914 年。II掌骨在其远端关节面的轴向边缘上有一个凹口；和第二指的远节指骨的甲突明显背掌变平。包括手足骨学特征的系统发育分析表明，在 Scelidotheriinae 家族中，Scelidotherium 与 Catonyx 的关系比与 Valgipes 或 Proscelidodon gracillimus Rovereto 的亲缘关系更密切，1914 年。