<div class="tree_txt_unlinked"><p><em>Aotus</em>, the owl monkey, is found throughout South America. Within this broad range exists several allopatric species: <em>A. azarae</em>, <em>A. hershkovitzi</em>, <em>A. lemurinus</em>, <em>A. miconax</em>, <em>A. nancymaae</em>, <em>A. nigriceps</em>, <em>A. trivirgatus</em>, and <em>A. vociferansis</em>. Owl monkeys are perhaps best-known for being the only nocturnal anthropoid. Like all anthropoids, however, <em>Aotus</em>
lacks the tapetum lucidum found in many nocturnal prosimians and
nonprimates. It is likely that owl monkeys secondarily evolved these
nocturnal habits. These medium-sized neotropical primates exhibit no
marked sexual dimorphism, have relatively long legs and tails, and have a
claw-like grooming nail on the second digit of both feet.</p>
<p><strong>Citations</strong>: Fleagle 1999</p>
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