New Middle Cambrian molluscs from the Láncara Formation of the Cantabrian Mountains (north-western Spain)

Resumen

An abundant and highly diverse fauna is characteristic for the nodular limestones of the upper member of the Láncara Formation. It consists of echinoderms, trilobites, brachiopods, molluscs, sponge- and chancelloriid remains, and other small shelly fossils. Whereas the trilobites of the Láncara Formation are well investigated, information on other faunal groups is clearly underrepresented. In this paper the Middle Cambrian helcionelloid molluscs and hyoliths of the upper member of the Láncara Formation from four sections are described for the first time. The mollusc fauna shows clear affinities to Siberia, South Australia, Greenland, and China. The following taxa were described: Protowenella lancaraensis new species, Mackinnonia cf. rostrata (Zhou & Xiao, 1984), Pelagiella subangulata (Tate, 1892), Conotheca sp., and Microcornus sp.