Platyrrhines are an enigmatic and intriguing radiation of New World monkeys that currently inhabit the western hemisphere from Argentina to Mexico. Platyrrhini, a taxonomic parvorder within Primates, is their formal taxonomic designation, as they represent the sister group of the Catarrhini or all of the Old World monkeys and apes. These platyrrhine monkeys are diverse in terms of body size, their ecology, and in their movement patterns. From the smallest anthropoid, Cebuella pygmaea, to the large bodied Brachyteles, platyrrhines inhabit the Amazon rain forest basins, the Atlantic coastal forests of Brazil, and the Central American rain forests. Their locomotor abilities range from arboreal quadrupedalism, to climbing and leaping preferences, to forelimb suspensory behaviors. It is the intention of this study to identify anatomical correlates in the hind limb of these New World monkeys relative to their respective movement patterns.', 'Forty-five species of platyrrhines, representing hundreds of individual specimens, were measured and analyzed to determine if morphology of the hip and pelvis, thigh and proximal femur, and/or knee, could be mapped to their known locomotor behavior. The features examined were chosen on the basis of previous studies conducted on platyrrhine primates or other mammals where hindlimb anatomy had been correlated with positional behavior. Behavioral studies that included quantified and qualitative descriptions were examined. Statistical analyses, including regressions and the analysis of variance were employed to determine if correlations between morphology and movements could be specified. ', 'Results from this study indicated that morphological adaptations for leaping are more generalized within platyrrhines than in “prosimian†primates. Dorsal ischial projection was found to be a good indicator of (vertical) leaping in pithecids for example, but not among callitrichids nor among platyrrhines as a whole. There are elements of the platyrrhine postcranium that are linked to climbing including a wide pubis, robust intertrochanteric crest and posteriorly placed lesser trochanter. The New World brachiators have increased their joint excursion range at the hip and evidence two features of the knee, a wide patellar groove and gracile medial condylar lip, that help to distinguish them morphologically from the other groups. ', 'Overall, this study demonstrates that the hindlimb morphology of the platyrrhines examined here are more generalized in nature and they are not as strongly indicative of the distinctive movement patterns as has been noted previously in “prosimian†primates or for the brachiating apes. Callitrichids, in particular (excluding Cebuella, the pygmy marmoset), although exhibiting differences in frequency and style of locomotor behaviors, actually do not vary very much morphologically in their hindlimb anatomy. While several monkeys, including Cebuella and Ateles species, stand out as being genuinely unique morphologically and do not fit the expectations of the movement hypotheses developed in this study. In the end, this project has identified features of the hindlimb that are indicative of certain locomotor behaviors, while also illustrating platyrrhine locomotor behavior in terms of a rather generalized hindlimb morphology.

Last modified

• 10/14/2019

Creator

• Michael S Mutehart

DOI

• https://doi.org/10.21985/n2-fyrn-4m08

Subject

• Driskill Graduate Training Program in Life Sciences

Keyword

• Primates
• Platyrrhines
• Hindlimb Suspension
• Leaping
• Hindlimb
• Primate Locomotion

Date created

• 2018-01-01

Resource type

• Dissertation

Rights statement

• In Copyright