Carpal anatomy and primate relationships

A comparative study of skeletonized and wet specimens of a broad sampling o f prosimian as well as anthropoid primates provides evidence for the first time of the diversity of morphology and articular relations of the carpals. phylogenetically, it appears that derived states within Primates support t he monophyly of a cheirogaleine-galagine-lorisime clade (marked contact bet ween the os centrale and the hamate), an Old World monkey clade (lack of a hamate process), and a New World monkey clade (medially truncated, but medi olaterally oriented os centrale with a laterally elongate, horizontally ori ented, distal extension that is overlapped extensively dorsally by the trap ezoid, and broad contact between the lunate and capitate). The latter featu res provide the first definitive demonstration of New World monkey monophyl y on the basis of easily recognized synapomorphy. Fusion of the os centrale and scaphoid seems to occur randomly among primates. This character is thu s best interpreted as autapomorphic for the relevant taxa.