Paralouatta varonai was described from a nearly complete cranium from the late Quaternary in 1991. This cranium and a number of isolated teeth and postcranial bones were found in the Cueva del Mono, a cave site in Pinar del Río Province. The initial description of the cranium included a proposal that Paralouatta varonai was a close Caribbean relative of the extant Alouatta (howler monkeys) of Central and South America,[1] but this taxonomic placement was called into question with the analysis of the dental remains.[2] Based on shared similarities with the three other Caribbean monkeys, Xenothrix mcgregori, Insulacebus toussaintiana, and Antillothrix bernensis, MacPhee and Horovitz have proposed that the Caribbean primates are part of a monophyletic radiation which entered the Caribbean at the Oligocene–Miocene boundary. Further research confirms this assessment and places these three species in the tribe Xenotrichini.[3] However, more recent research restores its close relationship with Alouatta.[4] The postcranial morphology of Paralouatta suggests that it was partly terrestrial,[5] and a likely example of island gigantism.[6]
Paralouatta had an estimated body mass of 8.4 kg (19 lb).[4] Analysis of postcranial morphology suggests that Paralouatta was at least somewhat semi-terrestrial, making it the most terrestrial platyrrhine genus known.[7]