International Journal of Primatology

, Volume 19, Issue 3, pp 599–613

Arboreal Quadrupedism and Forelimb Articular Anatomy of Red Howlers

  • Miguel A. Schön Ybarra

DOI: 10.1023/A:1020320708192

Cite this article as:
Schön Ybarra, M.A. International Journal of Primatology (1998) 19: 599. doi:10.1023/A:1020320708192


I describe the patterns of forelimb movements that facilitate adult red howling monkeys (Alouatta seniculus) to advance quadrupedally on arboreal trails in directions ± 45° from the horizontal, the articular surface morphology at the scapulohumeral and elbow joints, and the structure of the trails. Results indicate (1) that red howlers splay their forelimbs when advancing on arboreal trails of mesh-like substrates, but they do not splay them to proceed on unilineal arboreal trails, and (2) that the articular surfaces are adapted to enable the scapulohumeroulnar bony alignments that result in both splayed and nonsplayed forelimb motions. These results have implications for the locomotor habits of several fossil catarrhines.

Alouatta seniculushowlerforelimbsarboreal route frameworksjoint rotations

Copyright information

© Plenum Publishing Corporation 1998

Authors and Affiliations

  • Miguel A. Schön Ybarra
    • 1
  1. 1.Department of Anatomy, School of MedicineUniversity of Puerto RicoSan Juan