Epiphyseal fusion and postcranial age determination in the woolly mammoth Mammuthus primigenius

The long-bone epiphyses of the woolly mammoth fused, as in living elephants, over an extended period of the animal’s life. A series of associated male skeletons has been examined, and the state of epiphysis fusion plotted against ontogenetic age determined from dental progression and wear. This shows a consistent sequence of fusion from the distal humerus at around age 10 to the distal radius/ ulna at around age 45. The pattern is similar to that of living elephants with a few minor diff erences. This provides a means of roughly ageing woolly mammoth postcrania when dental remains are unavailable, and also provides data for the investigation of growth patterns among elephantid species. The Columbian mammoth fused its epiphyses in a similar order to the woolly mammoth, but circumstantial evidence suggests that, with a longer lifespan, the successive fusions may have occurred at earlier dental stages.