Cranial Anatomy of Shoshonius and the Antiquity of Anthropoidea

Abstract

A not. all, modern systematists agree that the living anthropoid or simiiform primates (New and Old World monkeys, apes, and humans) constitute a natural, monophyletic assemblage, there is widespread disagreement over whether or not certain fossil forms should be included in this taxon. Unfortunately, not all of this disagreement reflects the morphological ambiguity of such poorly known fossil taxa as Hoanghonius stehlini, Amphi-pithecus mogaungensis, Pondaungia cotteri, and Afrotarsius chatrathi. Rather, it is at least partly a result of different notions regarding how the taxon Anthropoidea should be defined. Obviously, a major prerequisite for understanding the origin and early evolutionary history of any group of organisms is a theoretically sound definition of what actually constitutes the taxon under investigation. Without this type of formal definition, a great deal of time and effort can be wasted by different investigators talking past one another about semantic issues that are largely irrelevant to the actual topic of debate.