Human Evolution

, Volume 1, Issue 3, pp 233–242

precision holding in humans, non-human primates, and Plio-Pleistocene hominids

  • M. M. Shrewsbury
  • A. Sonek

DOI: 10.1007/BF02436581

Cite this article as:
Shrewsbury, M.M. & Sonek, A. Hum. Evol. (1986) 1: 233. doi:10.1007/BF02436581


Four Types of precision holding in the human hand have been identified and described in accordance with the contrasting regional properties of a differentiated ungual pulp of the distal phalanx. Comparisons were made with the non-human primates for types of precision holding and for morphological features of the distal phalanx. Many non-human primates employ most types of precision behavior: one of these, Type 1, predominates and derives from the «set» of the grasping hand for power gripping during arboreal progression. Unlike that of humans, the ungual pulp of the non-human primates is undifferentiated. A distinction is made for the presence of an ungual tuft and ungual spines for humans and for their absence in the non-human primates. The distal phalanx of the Plio-Pleistocene hominids was evaluated for its role in precision holding. The variations in expression of the ungual tuft and the absence of ungual spines suggest an undifferentiated or incompletely differentiated ungual pulp. It is believed that most of the Types of precision holding were possible in the Plio-Pleistocene hominids; however, such Types were not utilized as in contemporary humans. The presence of ungual tufts and spines of the distal phalanx should be considered diagnostic features of the hominid hand. These features and the precision behavior inferred are integral elements in the hominization process.

Key words

hand primates precision holding distal phalanx ungual tuft fossil Hominids 

Copyright information

© Editrice II Sedicesimo 1986

Authors and Affiliations

  • M. M. Shrewsbury
    • 1
  • A. Sonek
    • 2
  1. 1.San Diego State UniversitySan DiegoU.S.A.
  2. 2.San Diego State UniversitySan DiegoU.S.A.

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