Abstract

A Cambrian Series 3 (Guzhangian, Lejopyge laevigata I Zone or L. laevigata II Zone) trilobite fauna is described from Christmas Hills, northwestern Tasmania. Eleven polymerid taxa are described including the new species Asthenopsis conandersoni. The genera Asthenopsis and Elyx are described for the first time from Tasmania. The nine agnostoid taxa include the cosmopolitan species Lejopyge laevigata, Acidusus aculeatus and Hypagnostus brevifrons. Cladistic analysis indicates that the Centropleuridae (Centropleura, Luhops, Clarella and Anopolenus) form part of the Paradoxidoidea, where they are more closely related to the Xystriduridae (Xystridura and Galahetes) than they are to the Paradoxididae (Paradoxides, Hydrocephalus, Mawddachites and Eccaparadoxides) and that the Ellipsocephalidae (Bergeroniellus and Lermontovia) are not part of the superfamily. The fossils occur within a deeply weathered laminated mudstone which, when fresh, was probably black and calcareous and deposited in an outer shelf setting.