New material of the earliest hominid from the Upper Miocene of Chad
New material of the earliest hominid from the Upper Miocene of Chad
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DOI：
10.1038/nature03392
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发表时间：
2005-04-07
期刊：
影响因子：
64.8
通讯作者：
Vignaud, P
中科院分区：
文献类型：
--
作者：
Brunet, M;Guy, F;Vignaud, P
使命团在乍得的发现极大地改变了我们对非洲早期人类进化的理解（1-3）。特别是，在托罗斯-梅纳拉地区的TM 266地点发现了一个几乎完整的头盖骨（TM 266-01-60-1）、一个下颌骨和几颗孤立的牙齿，这些牙齿被指定为乍得萨赫勒人（3），生物年代学上可以追溯到中新世晚期（大约700万年前）。尽管TM 266颅骨相对完整，但对其形态及其在原始人类分支中的地位仍存在一些争议（4，5）。在这里，我们描述了新的牙齿和下颌骨标本从三个Toros-Menalla（乍得）产牙的地方（TM 247，TM 266和TM 292）相同的年龄（6）。这种新材料，包括与非珩磨C/P-3复合体一致的下犬齿，具有原始牙根形态和中间放射状釉质厚度的后犬齿，归因于S。tchadensis。它扩大了该种的下位，并提供了额外的解剖特征，证实了S。乍得猿和非洲猿。S.乍得人呈现出几个关键的衍生特征，这与其在人科分支中接近黑猩猩和人类最后一个共同祖先的位置一致。
Discoveries in Chad by the Mission Paleoanthropologique Franco-Tchadienne have substantially changed our understanding of early human evolution in Africa(1-3). In particular, the TM 266 locality in the Toros-Menalla fossiliferous area yielded a nearly complete cranium (TM 266-01-60-1), a mandible, and several isolated teeth assigned to Sahelanthropus tchadensis(3) and biochronologically dated to the late Miocene epoch ( about 7 million years ago). Despite the relative completeness of the TM 266 cranium, there has been some controversy about its morphology and its status in the hominid clade(4,5). Here we describe new dental and mandibular specimens from three Toros-Menalla ( Chad) fossiliferous localities ( TM 247, TM 266 and TM 292) of the same age(6). This new material, including a lower canine consistent with a non-honing C/P-3 complex, post-canine teeth with primitive root morphology and intermediate radial enamel thickness, is attributed to S. tchadensis. It expands the hypodigm of the species and provides additional anatomical characters that confirm the morphological differences between S. tchadensis and African apes. S. tchadensis presents several key derived features consistent with its position in the hominid clade close to the last common ancestor of chimpanzees and humans.