1Lehman College, CUNY at the Division of Vertebrate Paleontology, American Museum of Natural History, 2New York Consortium in Evolutionary Anthropology, 3Department of Anthropology, The Graduate Center, City University of New York, 4Department of Evolutionary Anthropology, Duke University, 5Division of Vertebrate Paleontology, American Museum of Natural History, 6Institut Català de Paleontologia, Universitat Autònoma de Barcelona
Saturday All day, Plaza Level
Paralouatta varonai is a Miocene-sub-recent taxon from Cuba that is exceptionally well represented postcranially in the platyrrhine fossil record. The original description of this material posited an organism adapted for semi-terrestrial locomotion; this is notable as there are no primates within the extant platyrrhine radiation that practice terrestriality as a significant component of their locomotor repertoire. However, the original description also left open the possibility that some of these potentially terrestrial traits in Paralouatta (which are similar to those present in Old World monkeys) are actually plesiomorphies shared with a common anthropoid ancestor.
In order to clarify both the potential locomotor pattern of Paralouatta and the degree to which it is derived, each fossil element was compared to a broad sample of extant platyrrhines and cercopithecoids, as well as Miocene and Oligocene fossil primates from Africa and South America. Three-dimensional landmark data were collected using a Microscribe 3DX digitizer or using Landmark Editor and the data were subjected to standard multivariate statistical analyses.
Results indicate that while there may be a few characteristics derived towards semi-terrestrial locomotion, particularly in the phalanges and the olecranon process of the ulna, the strongest locomotor signal points towards an arboreal quadruped that would have included leaping as an important component of its repertoire, most similar to modern Chiropotes or Aotus. In addition, Paralouatta possessed a thumb that is longer than all modern atelids. Overall, the evidence suggests that Paralouatta had a less derived postcranial skeleton in comparison to extant atelids.
This study was partially funded by: NSF DDIG # 0925704 (LBH); NSF DDIG # 40761-0001 (SBC); Spanish Ministerio de Ciencia e Innovación (CGL2008-00325/BTE) and the Generalitat de Catalunya (2009 SGR 754 GRC and BP-A 00226 to SA).