Die Gattung Erratencrinurus Krueger, 1971 (Trilobita; Ordovizium) aus baltoskandischen Geschieben

Abstract

ZusammenfassungAus der mittel-bis oberordovizischen Trilobitenfamilie Encrinuridae, die in Baltoskandia durch die Untergattungen Erratencrinurus und Celtencrinurus reprasentiert wird, werden achtzehn Arten beschrieben, darunter die vier neuen Arten Erratencri- AbstractIn Baltoscandia the Middle to Late Ordovician trilobite family Encrinurida is represented by the two subgenera Erratencrinurus and Celtencrinurus. Out of these 18 species, four new species are described herein. Most of the material comes from the Ostseekalk which is an extremely hard rock and thus difficult to preparate. The tubercle formula after Tripp is applied to the Erratencrinurus group and led to the distinction of three different types of scutum rostrale shields. Various types of tubercles which may even pass into extreme spines are described. The number of thoracic spines becomes reduced from three spines in Middle Ordovician taxa to a single spine in youngest Ordovician species. Different parts of the carapace of Erratencrinurus sellinensis with pore canals are illustrated and a new moulting type of E. seebachi is introduced. New species are E. sellinensis. E. heinrichi, E. praecapricornu and E. (E.) rhebergeni.