New adapiform primate fossils from the late Eocene of Egypt

<p>Caenopithecine adapiform primates are currently represented by two genera from the late Eocene of Egypt (<i>Afradapis</i> and <i>Aframonius</i>) and one from the middle Eocene of Switzerland (<i>Caenopithecus</i>). All are somewhat anthropoid-like in several aspects of their dental and gnathic morphology, and are inferred to have been highly folivorous. Here we describe a new caenopithecine genus and species, <i>Masradapis tahai</i>, from the ~37 million-year-old Locality BQ-2 in Egypt, that is represented by mandibular and maxillary fragments and isolated teeth. <i>Masradapis</i> is approximately the same size as <i>Aframonius</i> but differs in having a more dramatic distal increase in molar size, more complex upper molar shearing crests, and an exceptionally deep mandibular corpus. We also describe additional mandibles and part of the orbit and rostrum of <i>Aframonius</i> which suggest that it was probably diurnal. Phylogenetic analyses place <i>Masradapis</i> either as the sister taxon of <i>Aframonius</i> (parsimony), or as the sister taxon of <i>Afradapis</i> and <i>Caenopithecus</i> (Bayesian methods). Bayesian tip-dating analysis, when combined with Bayesian biogeographic analysis, suggests that a common ancestor of known caenopithecines dispersed to Afro-Arabia from Europe between 49.4 and 47.4 Ma, and that a trans-Tethyan back-dispersal explains <i>Caenopithecus</i>’ later presence in Europe.</p> <p>For <i>Masradapis</i>: <a href="https://www.zoobank.org/urn:lsid:zoobank.org:act:41BC8459-7CCE-487F-BC59-1C34257D5C4E" target="_blank">https://www.zoobank.org/urn:lsid:zoobank.org:act:41BC8459-7CCE-487F-BC59-1C34257D5C4E</a></p> <p>For <i>Masradapis tahai</i>: <a href="https://www.zoobank.org/urn:lsid:zoobank.org:act:C0A620AD-6FCA-4649-A980-FCA237AFE39D" target="_blank">https://www.zoobank.org/urn:lsid:zoobank.org:act:C0A620AD-6FCA-4649-A980-FCA237AFE39D</a></p>