A Lower Carboniferous sipunculan from the Granton Shrimp Bed, Edinburgh

Sipunculans are sedentary marine worms, believed to represent either an early coelomate\ud grade or a later offshoot of the annelids, but are unmineralized and extremely rare in the fossil\ud record. Here we describe an example from the Granton Shrimp Bed, a Lower Carboniferous\ud Konservat-Lagerstatte. This is the third known occurrence of Palaeozoic sipunculans,\ud although they may have been previously overlooked. The recognition of fossil sipunculans is\ud discussed, based partly on cuticle deformation due to the underlying muscle arrangement