Radiographic evaluation of primate skeletal development
: a novel methodology for ascertaining age, and its implications

  • Annie E Mason

Student thesis: Master's ThesisMaster of Philosophy (MPhil)


This research demonstrates the usefulness of veterinary radiographs as a resource for furthering understanding of epiphyseal fusion in nonhuman primates. There are a range of benefits in using radiographic records as opposed to dry bone analysis, not least that it has the potential for longitudinal studies, and there already exists a wealth of data in zoos and similar institutions. 906 radiographs were described, depicting individuals from 25 different species of primate. All the radiographs were from Bristol Zoological Gardens, and all had been gathered for medical or care reasons. Focusing on the long bones (humerus, radius, femur, and tibia), a novel methodology is presented in which a nine stage scoring system is used to describe the formation, and fusion, of the epiphyses. This adds greater detail and nuance to previously published work on nonhuman primate epiphyseal fusion. The proximal humerus is most often statistically significant in the correlation between chronological age and epiphyseal fusion stage. The results are compared to behavioural markers of ontogeny such as weaning and puberty. It is demonstrated that some sexually monomorphic species exhibit rate hypermorphosis in one sex in regard to their epiphyseal fusion. We see that, in some species, the continued visibility of the epiphyseal scar can be used to determine the age of an individual. It is further demonstrated that the proximal femur is the first long bone to reach full fusion in the majority of species studied.
Date of Award23 Jan 2020
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorKate Robson Brown (Supervisor) & Tamar Hodos (Supervisor)


  • primate
  • skeletal development
  • ontogeny
  • radiograph
  • sexual dimorphism

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