The Systematic and Phylogenetic Significance of the Hominin Temporal Bone: A Landmark-Based Approach

这项研究解决了一系列悬而未决的问题，在人科动物的进化，使用新的和快速发展的方法，定量分析的骨形态的几何形态测量学领域。 研究人员建议分析早期原始人类头骨颞骨的比较解剖学，以便在用于将化石标本归因于物种的关键形态特征的识别上获得新的观点，并且更普遍地说，在进化背景下研究灵长类骨骼变异的方法论方法。 这两个研究领域都很困难，但都是关键性的，沿着回答有关早期人类进化的具体问题的道路。他们选择研究早期人类头骨的颞骨是因为：1）关于早期人类进化的几个争论都集中在颞骨上，它在解剖学上很复杂，在各种进化谱系中分化良好;（2）以往的分析主要集中在颞骨形态的定性比较上，没有在解决悬而未决的争论方面取得进展;（3）颞骨在人科化石记录中有很好的代表性; 4）他们的方法非常适合于研究碎片化石，碎片化石是整个颞骨样本的重要组成部分。研究原始人类颞骨，他们解决了这样一些悬而未决的问题：1）人类属最早记录的代表是什么？2)如果有的话，在传统上公认的物种中，如南方古猿阿法种，A。非洲人和其他？3)应该如何解释“强壮的”南方古猿物种和人属物种之间独特的亲缘关系（同源性与突触形态）的形态学标志？该方法采用三维标志的颞骨，以量化的形态特征，迄今为止，只进行了定性和/或在一个单变量的上下文中的表达。 具体来说，他们使用“相对翘曲分析”来量化整体形状的变化和“薄板样条分析”来描述和图形化描绘分类群或标本之间的差异。 我们的目标是识别颞骨形态的新方面，以区分原始人类类群。

This study addresses a series of unresolved issues in hominid evolution using new and rapidly developing approaches to the quantitative analysis of bone form in the field of geometric morphometrics. The researchers propose to analyze the comparative anatomy of the temporal bone of the early hominid cranium in order to arrive at fresh perspectives on the identification of key morphological characters used to attribute of fossil specimens to species, and, more generally, on methodological approaches to the study of primate skeletal variation in an evolutionary context. Both are difficult, but critical areas of research, along the road to answering specific questions concerning early hominid evolution.They chose to study the temporal bone of the early hominid cranium because: 1) several debates concerning early hominid evolution center on the temporal bone, which is anatomically complex and well differentiated in the various evolutionary lineages; 2) previous analyses have focused on qualitative comparisons of temporal bone form, which have not led to progress in resolving outstanding debates; 3) the temporal bone is well represented in the hominid fossil record; 4) their methods are well suited to the study of fragmentary fossils, which comprise a significant component of the total temporal bone sample.Studying the hominid temporal bone, they address such unresolved questions as: 1) What are the earliest documented representatives of the genus Homo? 2) How much, if any, taxonomic heterogeneity exists within conventionally recognized species such as Australopithecus afarensis, A. africanus, and others? 3) How should the morphological signs of unique affinity between "robust" Australopithecus species and Homo (homoplasy vs. synapomorphy) be interpreted? The approach employs three-dimensional landmarks on the temporal bone to quantify the expression of morphological features that have thus far been examined only qualitatively and/or in a univariate context. Specifically, they use "relative warp analysis" to quantify overall shape variation and "thin-plate spline analysis" to describe and graphically portray difference between taxa or specimens. The goal is the identification of novel aspects of temporal bone morphology to distinguish hominid taxa.