Early Llanvim brachiopods and trilobites occur together with molluscs as clasts in a serpentine conglomerate thought to have been formed in an oceanic island setting during an early closing of the lapetus Ocean. The brachiopods show strong North American affinities while the trilobites are a mixture of North American and Balto-Scandian types. The fauna suggests that in oceanic island settings, faunal provincial affinity in support of tectonic models should be used with caution. The twelve brachiopod genera include: Rutrumella implexa gen. et sp. nov., Ottadalenites incertus gen. et sp. nov., Neumania gen. nov. (type species: Atelelasma atlanticus Neuman, 1976) and Trondorthis subcircularis sp. nov. The nine trilobite genera include Asaphus (Neoasaphus)? sp. nov., Annamitella? cf. borealis Whittington, 1964, Turgicephalus cf. turgidus (Whittington, 1965) and Pliomerafischeri (Eichwald, 1825).
Brachiopods and trilobites of the early Ordovician serpentine Otta Conglomerate, south central Norway