The misbegotten: long lineages, long branches, and the interrelationships of Aotus, Callicebus, and the saki-uakaris

ROSENBERGER, A.L.; TEJEDOR, M.F.

Evolutionary Biology and Conservation of titis, sakis and uakaris (A.A. Barnett, L.M. Veiga, S.F. Ferrari, and M.A. Norconk, eds.)

Cambridge University Press

Lugar: London; Año: 2013; p. 13 - 22

An important shift in thinking demands renewed scrutiny concerning the course of New World monkey (platyrrhine) evolution and their classification. For the first time in nearly 200 years, the genus Aotus is being aligned with marmosets and tamarins (Callitrichinae) rather than titi monkeys and sakis-uacaris (Pitheciini) and, more generally, atelines. The emergence of this debate reflects the impact of molecular cladistics since the early 1990s. The conversation has turned from a prolonged controversy over callitrichines, a dispute that was fundamental to modernizing our views of platyrrhine evolution and appears to be resolved for the moment. Now, beginning with the successful molecular cladistic analysis of Schneider et al. (1993), attention shifts to Aotus. Is this genus a pitheciine, an atelid, a stem platyrrhine or a cebid? The prevailing opinions are that Aotus is either a cebid (Callitrichinae plus Cebinae) or a pitheciine (Pitheciini plus the [modern] Homunculini Callicebus and Aotus), but the crux of the matter is that the hypothesis of Aotus as a cebid relies almost entirely on genes, whereas arguments for its inclusion in the pitheciines is based wholly on morphology. While some morphologists align Aotus more closely with the molecular trees, we believe these assessments do not adequately account for anatomical evidence bearing on Aotus, Callicebus, Pithecia, Chiropotes and Cacajao, and their fossil relatives.