New Ordovician hyolith Elegantilites custos sp. n. and the palaeogeographic and stratigraphic distribution of the genus Elegantilites Marek, 1966

Abstract Elegantilites custos sp. n., a rare new hyolithid species is described from the late Middle to early Late Ordovician Dobrotivá Formation of the Prague Basin in the Barrandian area of the Czech Republic. The new taxon is based on excellently preserved external and internal moulds of three opercula and several conchs, collected from siliceous nodules and shales. Internal moulds of both conch and operculum bear small tunnels resembling the ichnogenera Pilichnus and Arachnostega . Specimens of the hyolithid genus Elegantilites have been described exclusively from the Ordovician of North African Gondwana. The stratigraphic range of this genus is from the Lower Ordovician (Tremadocian) to the Upper Ordvocian (Katian).