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Published on: September 16, 2013
Phalangeal curvature and positional behavior in extinct sloth lemurs (Primates, Palaeopropithecidae)
W L Jungers1, L R Godfrey, E L Simons
1Department of Anatomical Sciences, School of Medicine, State University of New York, Stony Brook, NY 11794-8081, USA.
Summary
Extinct sloth lemurs from Madagascar had highly curved finger and toe bones, indicating they were among the most suspensory mammals. This contrasts with their leaping relatives, the indrids.
Area of Science:
- Paleontology
- Primate Anatomy
- Evolutionary Biology
Background:
- Madagascar's paleontological record reveals a diverse extinct clade of
- sloth lemurs
- (palaeopropithecids), closely related to living indrids.
Purpose of the Study:
- To analyze the curvature of proximal phalanges in sloth lemurs and compare it with extant primates.
Main Methods:
- Computed phalangeal curvature (theta) as an indicator of hand and foot function in extinct sloth lemurs.
Main Results:
- Sloth lemurs exhibited significantly curved proximal phalanges, exceeding those of spider monkeys and siamangs, and approaching orangutan levels.
Conclusions:
- Phalangeal curvature in sloth lemurs strongly supports their highly suspensory positional behaviors, classifying them among the most suspensory mammals known.
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