Bryozoan fauna of the Upper Ordovician (Katian) of Alnif, Morocco (original) (raw)

Bryozoan fauna was discovered within the glaciogenic sediments of an Ordovician (Hirnantian) tunnel valley infill near Alnif, Morocco where it had been redeposited from the upper Tiouririne Formation (Ktaoa Group, Katian). This fauna contains four species-one esthonioporine, two trepostomes and one rhabdomesine cryptostome-of which three are new: Revalotrypa ramosa sp. nov., Radiotrypa alnifensis sp. nov. and Heminematopora gaetula sp. nov. The fourth species, Monotrypa sp., is described using open nomenclature. Branched colonies of R. alnifensis sp. nov. are the most abundant element of the bryozoan-rich floatstones of the upper Tiouririne Formation in which bryozoans were deposited after being transported for a short distance. The genus Radiotrypa was previously known exclusively from the Hirnantian of Sweden, and the genus Heminematopora was known from the Upper Ordovician of North America and Europe. Study of the internal morphology of Heminematopora confirmed the presence of heterozooecia in this genus.