Late Cambrian fossils from the Climie Formation, western Tasmania

Abstract

The Climie Formation, which is about 460 metres thick in the type section of the Dundas Group, contains the youngest known fossils within the Dundas Group. Just south of the Murchison Highway bridge over the Dundas Rivulet the Climie Formation is overturned, sheared and contains poorly preserved fossils in two main horizons, which are well exposed in road cuttings. The lower fauna occurs about 200 metres below the top of the formation, while the upper fauna occurs about 145 metres below the top of the formation. The lower fauna contains the inarticulate brachiopods Angulotreta(?) sp., and Lingulella(?) sp., plus the trilobites described herein as Olenus sp., Neoagnostus sp., Agnostus sp., and Ceratopygidae, gen et sp. indet. Five fragmentary trilobite specimens are left in open nomenclature. The upper fauna contains the inarticulate brachiopods described herein as Lingulella(?) sp., and Acrotretidae, incertae sedis plus the trilobites Agnostus sp., Lotagnostus(?) sp., Peltura(?) sp., and an unassigned member of the Olenidae. It is suggested that the lower fauna is probably of early post-Idamean age, with the higher fauna being slightly younger. Both faunas are of a cosmopolitan nature and indicate easy communication with the open ocean at the time of deposition.