Basic Primate Taxonomy:
Now here is where it gets interesting
The suborder of primates can be described as Prosimian and Anthropoids. Anthropoids are larger and contain monkeys and apes. Prosimians are considered to be early primates that tend to be small, solitary, dependent on olfactory communication, contain a tooth comb, grooming claw and exhibit tapetum lucidum (Sussman, 1992; Tattersall, 1993; Fleagle, 1999; Strier, 2011). Prosimians include lemurs, lorises, pottos, galagos and tarsiers. Tarsiers were placed within prosimian because they maintain many primitive characteristics (i.e. grooming claws, brain size/ architecture, small size and nocturnal lifestyle) (Goodman et al., 1999). However, an alternative classification scheme was developed in order to address the some structurally different features of the tarsier shared with Anthropoids.
The two suborders became; Strepsirhines and Haplorhines.
Haplorhines have several anatomical features that differ from Strepsirhines including the characteristic of a rhinarium. A rhinarium or moist nose refers to a nose that has a cleft extending into the mouth (think cat). Tarsiers have a rhinarium (Fleagle, 2013) while other prosimians do not. Another feature of haplorhines is the lack tapetum lucidum. Tarsiers lack tapetum lucidum and instead have large eyes that allow improved vision in low light a feature that differs from both prosimians and other nocturnal primates. (Pocock, 1918; Martin, 1973; Hendrickson et al., 2000). Tarsiers thus became part of Haplorhines which included monkeys and apes while Stepsirhines include all other prosimians (lemurs, lorises, pottos and galagos).
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