Family Atelidae

Subfamily Atelinae

• long prehensile tail covered on ventral surface with friction ridges, similar to fingerprints on human hand

   b.      Alouatta seniculus (red howler), A. belzebul (black-and-red howler), A. fusca (brown howler),
  A. palliata (mantled howler), A. villosa (Guatemalan howler), A. caraya (black howler)

• sexually dimorphic by size
• small incisors and largely sexually dimorphic canines
• mandible quite large and deep
• hyoid bone expanded into large, hollow, resonating chamber
• have poorly differentiated  thumb
• slow quadrupeds, rarely leap
• folivorous

c.       Lagothrix iagotricha (common woolly monkey) and L. flavicaud (yellow-tailed woolly monkey)

• sexually dimorphic in body size
• arboreal quadrupeds

d.      Ateles paniscus (black spider monkey), A. geoffroy (black-handed spider monkey), A. fusciceps 
(brown-headed spider monkey), A. belzebuth (long-haired spider monkey)

• long slender limbs
• females have long pendulous clitoris similar to males penis
• large broad incisors and small molars
• skull has large orbits, globular braincase and gracile mandible
• fingers and toes long and slender, lack external thumb
• arboreal quadrupeds, brachiation[1], and climbing
• when in trees use bipedalism

e.       Brachyteles arachnoides (woolly spider monkey or muriqui)

• largest non human primate in neotropics and one of primates species closest to extinction
• arboreal quadrupeds and suspensory movers
  

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[1] Brachiation – arboreal locomotion where animal progresses below branches by using only the forelimbs