Article

Ontogenetic variation and craniometric sexual dimorphism in the social giant mole-rat, Fukomys mechowii (Rodentia: Bathyergidae), from Zambia

Published in: African Zoology
Volume 45 , issue 2 , 2010 , pages: 160–176

DOI: 10.1080/15627020.2010.11657267

Author(s): C.T. Chimimba1 Department of Zoology and Entomology, South Africa , A.M. Sichilima Department of Zoology and Entomology, South Africa , C.G. Faulkes School of Biological and Chemical Sciences, U.K. , N.C. Bennett Department of Zoology and Entomology, South Africa

Keywords: Fukomys mechowii , Ontogenetic variation , Sexual dimorphism , Craniometrics , Zambia

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Abstract

The degree of maxillary molar tooth-row eruption and wear were used to assign samples of the social giant mole-rat, Fukomys mechowii, from Zambia, into nine relative age classes in order to assess ontogenetic (age) variation and craniometric sexual dimorphism, with reference to body mass. Univariate and multivariate statistical analyses showed craniometric differences between age classes 1–3 and age classes 5–9, with age class 4 being intermediate between these two age class groupings. This suggests that age class 4 lies at a point on a hypothetical growth curve where growth begins to stabilize. The intermediate placement of age class 4 in multivariate space broadly coincided with body mass categorizations into juveniles (age classes 1–3; <100 g), subadults (age class 4; c. 100–150 g), and adults (age classes 5–9; >150 g). The analyses also revealed the absence of sexual dimorphism in the relatively younger age classes 1–4 but its presence in the relatively older age classes 5–9, and these results are supported by data on body mass. These results may have implications in our understanding of the population and social structures, and reproductive strategies in this little-studied giant mole-rat.

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