The quaternary cuban platyrrhine Paralouatta varonai and the origin of Antillean monkeys.

We describe recently recovered dental and mandibular remains of the Cuban platyrrhine Paralouatta varonai, previously known from the holotype only (a nearly complete skull with very worn teeth). We also expand on the original description of the type specimen. Paralouatta is one of three extinct taxa of Greater Antillean Quaternary monkeys known from craniodental remains. The other two, Xenothrix mcgregori and Antillothrix bernensis, occurred in Jamaica and Hispaniola, respectively. It has been common practice to assume that Antillean monkeys were more closely related to individual mainland taxa than to each other. Thus, P. varonai was thought to be related to Alouatta; Antillothrix bernensis to Saimiri or Cebus; and X. mcgregori to Callicebus, or to callitrichines, or even to be of unknown affinity. With the discovery of well-preserved dental remains of Paralouatta, it can now be ascertained that this species was in fact very different from Alouatta. Cladistic analysis reveals a sister-group relationship between Antillothrix and Paralouatta, followed on the cladogram by Xenothrix and Callicebus (last taxon being the closest mainlaind relative of the Antillean clade). This conclusion has an important biogeographic implication: recognition of an Antillean clade, as advocated here, assumes only one primate colonization from the South American mainland, not several as previously believed.

A new fossil cebine from Hispaniola.

An incomplete mandibular fragment of a cebine monkey from an early Holocene Haitian cave deposit adds to the small but growing list of fossil Antillean primates. The jaw is of the correct size to belong to the same taxon as the partial maxilla of "Saimiri" bernensis from the Dominican Republic. Both finds probably represent a single species whose proximate ancestry lay closer to Cebus than to Saimiri, although more evidence will be required to substantiate this. No close relationship of the Hispaniolan fossils to the Jamaican platyrrhine Xenothrix is indicated. How monkeys managed to penetrate the West Indies is a biogeographical puzzle of the first order. Geographical vicariance events, island-hopping, and purposeful or inadvertent introduction by humans seem rather implausible devices. On the whole, long-distance, over-water rafting from the Americas remains the most likely mechanism for past land vertebrate immigration into the Caribbean.