A new obolellid brachiopod from the Wirrealpa Limestone (Cambrian; Stage 4), Flinders Ranges, South Australia

Obolellids are a monophyletic group of calcareous brachiopods with a worldwide distribution that often occur near the Series 2 (Stage 4)–Miaolingian Series (Wuliuan Stage) boundary. The poorly known taxon, Obolella wirrialpensis Etheridge, 1905 originally described from the lower Cambrian Wirrealpa Limestone in the Flinders Ranges has several unique character traits including prominent “stepped” concentric lamellae and, unusually for the family, lacks any type of radial ornament. The ventral valve has a well-defined acuminate beak and single asymmetrical tooth on the left side of a raised, orthocline ventral interarea platform that aligns with a wide median notch in the dorsal valve. This unique suite of character traits reveals the taxon to be a new endemic obolellid genus, here revised as Jagoellus n. gen., part of the late Stage 4 Chalasiocranos-Kaimenella shelly fossil zone and lower Kostjubella djagoran brachiopod assemblage zone from Australia.