from Africa to Madagascar. Alternatively, it may have closer ties to the aye-aye (Daubentonia madagascariensis) within the lemuroid (lemur) radiation. The cranial and dental morphology of Plesiopithecus resemble what is predicted of an aye-aye ancestor, with an arched cranial vault suggesting klinorhynchy (a marked angle between the palate and the basicranium, or the lower region of the braincase) similar to that of aye-ayes, significantly enlarged canines and/or incisors, reduced molars and premolars, a high muzzle, and anteriorly placed orbits. However, it lacked ever-growing incisors and the diastema found in the aye-aye. The increased anterior dentition is peculiar because it has only happened in lemuriforms, and has never been observed in any of the numerous adapiforms. Key to this possible close affinity with the aye-aye is the identity (canine vs. incisor) of the procumbent front teeth of both species, neither of which is definitively known. If they are different between the two species, then the similarities would be due to convergence. If they are the same tooth, then it may suggest a close phylogenetic relation and African origins for the aye-aye. If Plesiopithecus is an African relative of the aye-aye, it would suggest lemuroid primates colonized Madagascar twice. Molecular studies show that the aye-aye diverged early in the evolutionary history of lemurs, followed later by a sudden burst of diversification of the other four lemur families. If Plesiopithecus is an aye-aye relative, lemurs and aye-ayes would have diverged in Africa and the aye-aye ancestor would have colonized Madagascar separately from the other lemurs, which would have diversified immediately upon arrival to the island. If aye-ayes are more closely related to lemurs than Plesiopithecus, then only one colonization event occurred, with the aye-aye branching off first and then the other lemuroid families diverging several million years later following a major extinction event. Taxonomy Plesiopithecus teras was first described in 1992 by paleoanthropologist Elwyn L. Simons. The holotype, which was found at the base of the Jebel Qatrani Formation at the Egyptian Fayum in quarry L-41 and dated to the latest Eocene, included a right mandible with intact dentition ranging from the third molar up to the first anterior tooth. Simons acknowledged that the taxonomic interpretation was complicated, though he initially decided to classify under superfamily Hominoidea (apes) due to its flat and broad lower molars. Its bizarre and specialized traits made it difficult to classify until the discovery of its skull, reported