A new Early Jurassic radiolarian fauna from the Murihiku Supergroup of the Otago coast, New Zealand

Abstract

Lower Jurassic Radiolaria are documented from Aratauran strata of the Murihiku Supergroup at the northern end of Sandy Bay, south of Nugget Point, Otago, New Zealand. The fossils were extracted from small carbonate nodules in fine grey sandstone in the middle part of the Aratauran sequence. The following genera were identified: Eptingium(?), Gigi, Hsuum, Orbiculiforma, Pantanellium, Paronaella(?), Poulpus(?), Saitoum, Spongostaurus(?), and Thetis. Comparison with radiolarian faunas of Europe, southwest Japan, and North America suggests that the study fauna is of Pliensbachian age, probably Early Pliensbachian, indicating the possibility that the Aratauran local stage, previously equated approximately with Hettangian-Sinemurian internationally, extends into the Early Pliensbachian.