Abstract：
Sahelanthropus tchadensis has raised much debate since its initial discovery in Chad in 2001, given its controversial classification as the earliest representative of the hominin lineage. This debate extends beyond the phylogenetic position of the species, and includes several aspects of its habitual behavior, especially in what regards its locomotion. The combination of ancestral and derived traits observed in the fossils associated with the species has been used to defend different hypotheses related to its relationship to hominins. Here, the cranial morphology of Sahelanthropus tchadensis was assessed through 16 linear craniometric measurements, and compared to great apes and hominins through Principal Component Analysis based on size and shape and shape information alone. The results show that S. tchadensis share stronger morphological affinities with hominins than with apes for both the analysis that include size information and the one that evaluates shape alone. Since TM 266-01-060-1 shows a strong morphological affinity with the remaining hominins represented in the analysis, our results support the initial interpretations that S. tchadensis represents an early specimen of our lineage or a stem basal lineage more closely related to hominins than to Panini.
摘要：
自从2001年在乍得首次发现Sahelanthropustchadensis以来，它就引起了很多争论，因为它被认为是人类谱系的最早代表。这场辩论超出了物种的系统发育位置，包括其习惯性行为的几个方面，尤其是在它的运动方面。在与该物种相关的化石中观察到的祖先和衍生特征的组合已被用来捍卫与其与人类的关系有关的不同假设。这里,通过16次线性颅骨测量，评估了Sahelanthropustchadensis的颅骨形态，并通过仅基于大小，形状和形状信息的主成分分析与大猿和人猿进行比较。结果表明，在包括大小信息的分析和仅评估形状的分析中，与人猿相比，tchadensis具有更强的形态亲和力。由于TM266-01-060-1与分析中代表的其余人源蛋白显示出强的形态亲和力，我们的结果支持了最初的解释，即S.tchadensis代表了我们谱系的早期标本或与人源比与Panini更密切相关的茎基底谱系。
