Trace fossils from the Lower Cambrian Pipe Rock of the north-west Highlands

Detailed descriptions are given of the trace fossils Skolithos and Monocraterion in the Lower Cambrian Pipe Rock, which have hitherto been referred to as ' ordinary pipes ' and ' trumpet pipes ' respectively. They are interpreted as the dwelling burrows of the same type of suspension-feeding worm-like organism. Skolithos was probably formed during periods of negligible sedimentation, whereas Monocraterion probably resulted from upward movement in adjustment to influxes of sediment.