White Jessica L, Gebo Daniel L
Department of Anthropology, Northern Illinois University, DeKalb, Illinois, USA.
Am J Primatol. 2004 Nov;64(3):293-308. doi: 10.1002/ajp.20079.
Although the morphology of the tibial plateau in primates has received very little attention in the literature, it does exhibit features of phylogenetic and functional interest. This paper describes the morphology of the tibial plateau (particularly the intercondylar region) in extant and fossil primates, and in three mammalian outgroups: the pen-tailed tree shrew (Ptilocercus), tree shrew (Tupaia), and flying lemur or dermopteran (Cynocephalus). Extant and fossil strepsirrhine primates exhibit an eminence with a single spine, which contrasts with the intercondylar morphology of haplorhine primates. Most extant platyrrhines, all catarrhine primates (including humans), and some fossil haplorhines possess an eminence with two spines (medial and lateral) connected by a ridge of bone that intersects the intercondylar groove. Tarsius and callitrichines possess an eminence with a reduced medial spine that superficially resembles that of strepsirrhine primates. Dermopterans also exhibit a morphology similar to that of strepsirrhines. In Scandentia, the intercondylar morphology of Tupaia is similar to that of rodents, whereas Ptilocercus resembles tarsiers and callitrichines. We hypothesize that proximal tibiae with either a single spine or reduced medial spine morphology facilitate a greater degree of knee rotation about the eminence relative to the double-spine condition, and are likely associated with more frequent adoption of vertical body positions. In contrast, a double-spine eminence limits knee rotation and is probably associated with greater use of horizontal supports. Although the polarity is complicated by the unknown phylogenetic status of likely sister taxa, it seems most probable that the single-spine morphology is a derived feature of strepsirrhines.
尽管灵长类动物胫骨平台的形态在文献中很少受到关注，但它确实展现出了系统发育和功能方面令人感兴趣的特征。本文描述了现存和化石灵长类动物以及三种哺乳动物外群（笔尾树鼩、普通树鼩和鼯猴）的胫骨平台（特别是髁间区域）的形态。现存和化石狐猴型灵长类动物表现出一个带有单一嵴的隆起，这与类人猿型灵长类动物的髁间形态形成对比。大多数现存阔鼻猴类、所有狭鼻猴类灵长动物（包括人类）以及一些化石类人猿型灵长动物都拥有一个带有两个嵴（内侧和外侧）的隆起，这两个嵴由一条与髁间沟相交的骨嵴相连。眼镜猴和狨猴科动物拥有一个内侧嵴退化的隆起，表面上类似于狐猴型灵长类动物的隆起。鼯猴也表现出与狐猴型灵长类动物相似的形态。在树鼩目中，普通树鼩的髁间形态与啮齿动物相似，而笔尾树鼩则类似于眼镜猴和狨猴科动物。我们推测，相对于双嵴的情况，具有单一嵴或内侧嵴退化形态的近端胫骨在隆起周围有助于更大程度的膝关节旋转，并且可能与更频繁地采用垂直身体姿势有关。相比之下，双嵴隆起限制了膝关节旋转，并且可能与更多地使用水平支撑有关。尽管由于可能的姐妹类群的系统发育地位未知而使极性变得复杂，但单嵴形态似乎最有可能是狐猴型灵长类动物的衍生特征。
