A peculiar climbing Megalonychidae from the Pleistocene of Peru and its implication for sloth history
A peculiar climbing Megalonychidae from the Pleistocene of Peru and its implication for sloth history
复制标题
秘鲁更新世一种奇特的攀缘巨爪科动物及其对树懒历史的意义
DOI：
10.1111/j.1096-3642.2007.00240.x
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发表时间：
2007
影响因子：
2.8
通讯作者：
L. Werdelin
中科院分区：
文献类型：
--
作者：
F. Pujos;G. Iuliis;C. Argot;L. Werdelin
异节动物，特别是缓步动物，是与Notoungulata和有袋动物最多样化的南美洲哺乳动物。卢贾尼亚南美洲陆地哺乳动物时代的地点从沿海彼德拉埃斯克里塔网站和安第斯卡萨德尔暗黑破坏神洞穴，秘鲁，已经产生了三个标本的巨爪科Diabolotherium nordenskioldi新属。这种奇异的化石树懒表现出一个特殊的镶嵌颅和颅后字符。有些被认为与其他树懒的牙齿趋同（例如5/4的四边形牙齿，是树懒科的特征），而另一些则清楚地表明了与现存树懒的悬挂模式不同的攀爬能力。诺登氏树懒的树栖生活方式表现在手肘、髋和踝关节的活动性相当大，尺骨后凸，鹰嘴比窝栖分类群短，放射状切迹比其他化石树懒更向前，与冠状突形成钝角（这增加了旋前-旋后的范围）、近远侧压缩的舟状骨和大范围的手指屈曲。诺登斯科尔迪强调了缓步动物的巨大适应性：一种适应于树栖的形式现在被添加到已知的陆地，亚树栖和水生（海洋和淡水）化石树懒中。缓步动物门的初步系统发育分析证实了Meanioidea、Nothrotheriidae、Meanioiidae和Megalonychidae的单系性，其中Diabolotherium强烈嵌套。
The Xenarthra, particularly the Tardigrada, are with the Notoungulata and Marsupialia among the most diversified South American mammals. Lujanian South American Land Mammal Age localities from the coastal Piedra Escrita site and Andean Casa del Diablo Cave, Peru, have yielded three specimens of the Megalonychidae Diabolotherium nordenskioldi gen. nov. This singular fossil sloth exhibits a peculiar mosaic of cranial and postcranial characters. Some are considered convergent with those of other sloths (e.g. 5/4 quadrangular teeth, characteristic of Megatheriidae), whereas others clearly indicate climbing capabilities distinct from the suspensory mode of extant sloths. The arboreal mode of life of D. nordenskioldi is suggested by considerable mobility of the elbow, hip, and ankle joints, a posteriorly convex ulna with an olecranon shorter than in fossorial taxa, a radial notch that faces more anteriorly than in other fossil sloths and forms an obtuse angle with the coronoid process (which increases the range of pronation–supination), a proximodistally compressed scaphoid, and a wide range of digital flexion. D. nordenskioldi underscores the great adaptability of Tardigrada: an arboreally adapted form is now added to the already known terrestrial, subarboreal, and aquatic (marine and freshwater) fossil sloths. A preliminary phylogenetic analysis of the Tardigrada confirmed the monophyly of Megatherioidea, Nothrotheriidae, Megatheriidae, and Megalonychidae, in which Diabolotherium is strongly nested. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 149, 179–235.