Intraspecific variability of beaver teeth (Castoridae: Rodentia)

Abstract

The metric variability of the teeth of Castor fiber Linné, 1758 and Castor canadensis Kuhl, 1820 with age are assessed. The ages of the studied specimens of C. fiber range from about 2 months to 16-17 years. Measurements of all teeth are given, and show a large range of size variation over all ages. The greatest size ranges can be observed for incisors, premolars, and third molars. Size variations of the fossil beavers Steneofiber eseri v. Meyer, 1846, Steneofiber castorinus Pomel, 1847, Anchitheriomys suevicus Schlosser, 1884, and Trogontherium cuvieri Fischer de Waldheim, 1809 are compared with those of C. fiber, and are of the same range and magnitude. It seems that it is nearly impossible to age beavers exactly with non-invasive methods on the basis of tooth morphology, namely by the form and pattern of enamel islands on the chewing surface of the cheek teeth. Therefore, in conclusion, it is suggested that the observed variability in the size of fossil beaver teeth should be interpreted as changes with age in accordance with the overall size range in C. fiber. © 2009 The Linnean Society of London.