Postcranial Morphology of Adalatherium hui (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar
Postcranial Morphology of Adalatherium hui (Mammalia, Gondwanatheria) from the Late Cretaceous of Madagascar
复制标题
马达加斯加晚白垩世 Adalatherium hui（哺乳动物、冈瓦纳动物）的颅后形态
DOI：
10.1080/02724634.2020.1799818
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发表时间：
2020
影响因子：
1.4
通讯作者：
Krause, David W.
中科院分区：
文献类型：
--
作者：
Hoffmann, Simone;Hu, Yaoming;Krause, David W.
来自马达加斯加晚白垩纪的adalatherium huiia的完整模式和唯一已知标本保存了Gondwanatheria的第一个颅后骨骼。它是根据冈瓦纳的颅骨后材料描述的第四种中生代哺乳动物（其他的是morganucodontansMegazostrodonandErythrotheriumand stem therianVincelestes）。adalatherium的颅后骨骼几乎是完整的，它的保存是特殊的；甚至肋软骨、手籽和足籽也被保存了下来。adalatherium表现出多种衍生和多形特征，可能反映了马达加斯加在地理上孤立的漫长进化史。这些奇怪的特征包括胫骨中外侧受压和前后弯曲，异常多的躯干椎骨（至少16节胸椎和12节腰椎），短尾和黄芪上的舟状突滑骨。除了这些特征外，无椎动脉在其胸带处表现出衍生性和多形性特征：喙突发育良好，占盂窝的一半，没有单独的前喙突，胸锁关节似乎是可活动的。腹面肩胛盂和发育良好的肱骨滑车表明前肢姿势相对为副矢状。后肢和骨盆带的显著特征包括一个大的闭孔，大小与母猴相似，一个大的腓骨旁，以及耻骨外。骨盆带和后肢之间的关节与胸带和前肢之间的关节形成对比，因为它表明了一个伸展的姿势。
The holotype and only known specimen ofAdalatherium huifrom the Late Cretaceous of Madagascar preserves the first postcranial skeleton for the Gondwanatheria. It represents only the fourth Mesozoic mammaliaform described from articulated postcranial material from Gondwana (the others being the morganucodontansMegazostrodonandErythrotheriumand the stem therianVincelestes). The postcranial skeleton ofAdalatheriumis virtually complete, and its preservation is exceptional; even costal cartilages and manual and pedal sesamoids are preserved.Adalatheriumexhibits a variety of derived and plesiomorphic traits, probably reflective of a long evolutionary history in geographic isolation on Madagascar. Among the bizarre features are a mediolaterally compressed and anteroposteriorly bowed tibia, an unusually high number of trunk vertebrae (at least 16 thoracic and 12 lumbar vertebrae), a short tail, and a trochleated navicular facet on the astragalus. Aside from these features,Adalatheriumdisplays derived and plesiomorphic characteristics in its pectoral girdle: the coracoid is well developed and contributes to half of the glenoid fossa, a separate procoracoid is absent, and the sternoclavicular joint appears to have been mobile. A ventrally facing scapular glenoid and the well-developed humeral trochlea suggest a relatively parasagittal forelimb posture. Notable features of the hind limb and pelvic girdle include a large obturator foramen similar in size to that of therians, a large parafibula, and the presence of epipubic bones. Articulation between the pelvic girdle and hind limb is in contrast to that between the pectoral girdle and the forelimb in that it is indicative of a sprawling posture.