Coleoptera from the Cromerian Type Site at West Runton, Norfolk, England

Abstract

A large assemblage of Coleoptera (beetles) has been investigated from a sequence of samples taken during excavations to recover a near complete mammoth skeleton between 1992 and 1995 from the Type Site for the Cromerian Interglacial at West Runton, Norfolk. The samples were taken from the same locality as that used for pollen, macroscopic plant remains and mollusc analyses. Only the lowermost part of this sequence yielded insect fossils. The upper samples seem to have been oxidised and any coleopteran remains decomposed beyond recognition. This beetle assemblage provides a detailed mosaic picture of the local environment at the time when the organic sediment accumulated. For the most part, the sediments were deposited in a sluggish river that meandered through a widespread reed swamp, with episodes of flooding. Occasional patches of open water supported water lilies and duckweed. Away from the swamp the better drained ground supported both deciduous trees such as oak, elm and hazel as well as sparse conifers such as spruce and pine. The dry ground vegetation also included heathers and open glades of grassland.The beetles indicate that the climate at the time was about as warm as that in East Anglia at the present day with enough precipitation available during the summer months to maintain the varied marsh habitats. The scarcity of the wholly terrestrial dung and carcase beetles in this assemblage suggests that the mammoth cadaver probably finished up in its present location in such waterlogged conditions that there were no acceptable habitats available for them in the immediate vicinity.