Morgan Michèle E, Lewton Kristi L, Kelley Jay, Otárola-Castillo Erik, Barry John C, Flynn Lawrence J, Pilbeam David
Peabody Museum of Archaeology and Ethnology and
Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138; Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA 02118;
Proc Natl Acad Sci U S A. 2015 Jan 6;112(1):82-7. doi: 10.1073/pnas.1420275111. Epub 2014 Dec 8.
We describe a partial innominate, YGSP 41216, from a 12.3 Ma locality in the Siwalik Group of the Potwar Plateau in Pakistan, assigned to the Middle Miocene ape species Sivapithecus indicus. We investigate the implications of its morphology for reconstructing positional behavior of this ape. Postcranial anatomy of extant catarrhines falls into two distinct groups, particularly for torso shape. To an extent this reflects different although variable and overlapping positional repertoires: pronograde quadrupedalism for cercopithecoids and orthogrady for hominoids. The YGSP innominate (hipbone) is from a primate with a narrow torso, resembling most extant monkeys and differing from the broader torsos of extant apes. Other postcranial material of S. indicus and its younger and similar congener Sivapithecus sivalensis also supports reconstruction of a hominoid with a positional repertoire more similar to the pronograde quadrupedal patterns of most monkeys than to the orthograde patterns of apes. However, Sivapithecus postcranial morphology differs in many details from any extant species. We reconstruct a slow-moving, deliberate, arboreal animal, primarily traveling above supports but also frequently engaging in antipronograde behaviors. There are no obvious synapomorphic postcranial features shared exclusively with any extant crown hominid, including Pongo.
我们描述了一件来自巴基斯坦波托瓦尔高原西瓦利克群一个1230万年前地点的部分无名骨（YGSP 41216），它被归入中新世中期的猿类物种印度西瓦古猿。我们研究了其形态对于重建这种猿的姿势行为的意义。现存狭鼻猿的颅后解剖结构分为两个不同的组，特别是在躯干形状方面。在一定程度上，这反映了不同但可变且重叠的姿势行为模式：猕猴类为前位四足行走，类人猿为直立姿势。YGSP无名骨（髋骨）来自一只躯干狭窄的灵长类动物，与大多数现存猴子相似，与现存猿类较宽的躯干不同。印度西瓦古猿及其较年轻且相似的同类西瓦西瓦古猿的其他颅后材料也支持这样一种类人猿的重建，其姿势行为模式更类似于大多数猴子的前位四足模式，而不是猿类的直立模式。然而，西瓦古猿的颅后形态在许多细节上与任何现存物种都不同。我们重建了一种行动缓慢、动作谨慎且树栖的动物，它主要在支撑物上方移动，但也经常进行反前位行为。没有明显的颅后共有衍征特征是与任何现存冠群人科动物（包括猩猩）所特有的。
