The Ordovician cheirurid trilobite PlacoparinaStaff: R.M. Owens [and P. D. Lane, Keele University]
The cheirurid trilobite Placoparina sedgwickii is known from relatively little material, all of it from Wales and the Welsh Borderland. The original specimen upon which this species was based was found by Professor Adam Sedgwick when he visited the Builth district in the 1830s. The handful of specimens collected up to the 1970s has been augmented in more recent times by additional material collected by Dr Peter Sheldon and by Dr Robert Kennedy, and together these provide sufficient morphological information for it to be characterized fully, and to be distinguished from the closely related P. shelvensis from the Welsh Borderland. Both species appear to be restricted to a particular biofacies, where they occur with suites of similar raphiophorid, asaphid, trinucleid and calymenid trilobites.