Because anthropoids are higher primates, much research has focused on their origins. However, there are a number of factors that make anthropoid origins problematic. To begin with, there are a number of purported “first” specimens. Fossils from Burma (Myanmar), North Africa, and Germany have been advanced as the first anthropoids. This diverse material indicates that there are differences in opinion about the proto-anthropoids. Were they tarsiiform or adapiform primates? If they were tarsiiforms, were they close relatives of the living tarsiers or an extinct member of the tarsiiform omomyids? A concomitant consideration is this: what is the position of the tarsier lineage? Is it a sister group to the anthropoids, which would be reflected by sorting both tarsiers and anthropoids into the Suborder Haplorhini? Alternatively, did anthropoids arise from adapiform primates?

Resolving the phyletic position of the living tarsiers (Infraorder Tarsiiformes) is crucial before these questions can be answered. During the Eocene, tarsiiform primates had a widespread distribution throughout the northern hemisphere. Living members of this Infraorder (tarsiers) are now found only in some Indonesian islands (Borneo, Sumatra, and Sulawesi) and in the Philippines. Genomic sequences from living primates, spread across about 90 percent of the living genera, demonstrate that tarsiers are an ancient relict lineage distantly related to anthropoids (Perelman et al., 2011). The living tarsiers have the longest lineage documented by fossils of all primates. The earliest member of the Family Tarsiidae is Xanthorhysis, found in the Middle Eocene of Shanxi Province, China, at about 45 mya (Beard, 1998a). But a number of phenotypic traits found in living tarsiers occur in fossil primates with no close relationships to the family. For example, 50 mya crania of Shoshonius cooperi from Wyoming superficially resemble the cranium of Tarsius (Beard et al., 1991).