Taphonomy of the West Runton Mammoth

Abstract

A substantially complete skeleton of a huge male mammoth Mammuthus trogontherii (estimated weight in life 9 tonnes) was excavated from the West Runton Freshwater Bed (the Cromerian stratotype) at West Runton on the North Sea coast of Norfolk, UK, over the period 1990–1995. The high standard of excavation of the skeleton and subsequent careful preparation and conservation provides much detailed evidence relevant to the taphonomic history of the mammoth assemblage. The wear on the molars indicates that it was about 41 years old at the time of death compared with a life expectancy of about 64, so that it had died prematurely. The fact that the West Runton Mammoth had sustained a severe injury to its right knee, which would have left it disabled and debilitated, might have led indirectly to its premature demise. The dead animal appears to have lain on its right side in shallow water and waterlogged silts, and soon after death the skin probably began to split exposing the ribs on the left side and the ends of the neural spines of the vertebrae to scavenging by spotted hyaenas, and perhaps also other animals. The feet were also extensively chewed at an early stage. Subsequently the skeleton appears to have been dismembered and scattered – the smaller bones probably by scavengers – and hyaenas further chewed the bones. At various stages hyaena coprolites were deposited around the carcass. Other mammoths, like modern elephants probably attracted to the remains of their own kind, were presumably responsible for moving the larger and heavier bones, skull and tusks, and removing the left tusk from the skull. They also appear to have extensively trampled the site, pushing bones down into the sediment and producing numerous scratches (inferred trampling marks). The mandible and left ulna were subaerially weathered where they protruded above the water and silt, while the similarly exposed top of the skull disintegrated in situ as the silt built up around it. The West Runton Mammoth and associated finds provide unique information on the palaeobiology of both spotted hyaena Crocuta crocuta and ‘steppe’ mammoth M. trogontherii in the early Middle Pleistocene.