Morphological trends and new species of Cyphaspis (Trilobita, Otarioninae) in the Devonian of Morocco, Turkey, Germany and Belgium

New species of the otarionine trilobite Cyphaspis are recorded from Pragian to Givetian localities in Morocco and Belgium. The material carries a wealth of new insights into the diversity of Cyphaspis during the Devonian. In an attempt to bring structure to the vast assortment of species, selected taxa are clustered into three informal groups that need to be validated in future analyses: the agayuara group for Siluro-Devonian species that retain a primitive morphology, the hamidi group for comparatively small, Emsian to Eifelian species with convergences on Otarion, and the ceratophthalmus group which encompasses the type species of Cyphaspis, C. ceratophthalmus (Goldfuss, 1843), and similar species. Morphological trends in each of the groups are briefly elaborated on. Twelve new species are recorded from Morocco: C. bluhmi sp. nov., C. eximia sp. nov., C. foumzguidensis sp. nov., C. heisingi sp. nov., C. ihmadii sp. nov., C. juergenhollandi sp. nov., C. khraidensis sp. nov., C. kippingi sp. nov., C. lerougei sp. nov., C. maharchensis sp. nov., C. smeenki sp. nov., C. tadachachtensis sp. nov. One additional species, C. boninoi sp. nov., is recorded from Belgium. Topotypical material of C. ceratophthalmus from Germany and the holotype of C. goerlichi (Haas, 1968) from Turkey are illustrated for comparisons to the other species. The holotype of C. ceratophthalmus could not be traced and a neotype is designated.