The cuticular structure of the 495‐Myr‐old type species of the fossil worm Palaeoscolex , P. piscatorum (?Priapulida)

Latex impressions of the cuticle of a compression fossil of the ? priapulid Palaeoscolex piscatorum , from the Lower Ordovician of Shropshire, demonstrate a complex ornamentation of sclerites similar to isolated material, e.g. Hadimopanella and phosphatized arrays. Each ‘segment‘is defined by an intercalary zone and bears two rows of sub‐circular plates with prominent nodes on the upper surface. The intercalary zone bears two narrow grooves and a series of platelets, similar to but smaller than the plates. The remainder of each segment is occupied by microplates. Palaeoscolex piscatorum is fairly similar to a number of other species, including Gamoscolex herodes and Milaculum elongatum. Present evidence suggests the palaeoscolecidans are priapulid worms (or near relatives). Their abundance, combined with records from Burgess Shale‐like occurrences, suggest priapulids were a major component of many Lower Palaeozoic benthic communities.