A new genus and four new species of Cylindropsyllidae Sars, 1909 (Copepoda: Harpacticoida) from the Great Meteor Seamount plateau (North-East Atlantic Ocean), with remarks on the phylogeny and the geographical distribution of the taxon

The Great Meteor Seamount plateau comprises three regions (north, middle, south), and sampling across the whole area, six species of Cylindropsyllidae Sars, 1909 were discovered. These species were homogenously distributed, indicating that the community of Cylindropsyllidae on the plateau was not zonated according to geographical features, but might be influenced by the presence of microhabitats. The new genus Monsmeteoris gen. nov. is characterized by the presence of two segments distally inserted to the swollen segment with aesthetasc on the male antennule, five elements on the antennal enp2, and completely reduced P4 endopod. Two new species, M. wiesheuorum sp. nov. and M. reductus sp. nov. are hereby described. Additionally, two closely related species belonging to Cylindropsyllus Brady, 1880 are described: C. valentini sp. nov. and C. flexibilis sp. nov., having at most two distal setae on the mandibular endopod, the inner seta of P4 enp2 lost, strongly pronounced styliform proximal part of seta V on the caudal rami, and an apical process on the female P3 enp2.