Redescription of Scalpellopsis Striatociliata Broch, 1922, with a Discussion on Its Phylogenetic Position and the Peduncular Plate Pattern in Scalpellids

The adult of Scalpellopsis striatociliata and the ontogeny of its capitular and peduncular plates are described. During ontogeny, S. striatociliata develops the carino-lateral (CL) and inframedian (L2) plates heterochronously after some peduncular plates (cl), which is unique. The position of Scalpellopsis as sister-group of the other scalpellids is reaffirmed. The Scalpellidae have diverse peduncular plate patterns, with the 8-plated pattern being ancestral and the most widespread among the genera. The peduncular plate patterns of several species of Scalpellidae are presented.