'A good collection of well-arranged trilobites looks better in the cabinet than perhaps any other fossils', wrote J.E. Taylor in Our Common British Fossils, published in 1885. Such is their popular appeal that trilobites have always been some of the most eagerly sought after of all fossils. Their name, suggested by their singular three-lobed appearance is derived from 'Trilobitae', introduced by the German naturalist Johann Walch in 1771 in his Der Naturgeschichte der Versteinerungen ('Natural History of Petrefactions'). The study of trilobites has particularly long associations with Wales, and the ancient rocks which crop out over much of the Principality have been well known as a rich source of them for nearly 300 years. This article outlines some of the history of their investigation in the area, describes their occurrence there, and discusses aspects of their nomenclature and morphology which are well illustrated by Welsh examples. <...>
