Systematics and phylogeny of the Ancorabolidae (Copepoda: Harpacticoida). 1. The <i>Ancorabolus</i>-lineage, with the description of three new genera

The Ancorabolus-group is recognized within the sub-family Ancorabolinae (Harpacticoida, Ancorabolidae) comprising Ancorabolus, Arthropsyllus and three new genera: Breviconia gen. nov., Juxtaramia gen. nov and Uptionyx gen. nov. The common ancestry of these genera is supported by antennulary segmentation, rostral morphology, cephalothoracic sensillar patterns, presence of lateral body processes, elongation of P1 endopod, segmentation of male P3 endopod and P5 armature in both sexes. Two new species of Ancorabolus are described from Frierfjord/Langesundfjord in Norway. A. inermis sp. nov. and A. confusus sp. nov. occur sympatrically in southern Scandinavia and can be readily differentiated by the pattern of body processes. Re-examination of Sars' (1909) material revealed that his widely adopted redescription of the type species A. mirabilis was based on an amalgamate of these two species. All records of A. mirabilis from outside the Firth of Clyde (Scotland) which cannot be identified as A. inermis or A. confusus have to be regarded as unconfirmed. Norman's (1903) material of A. mirabilis collected in East Finmark (Norway) and erroneously designated as types, is radically divergent in cephalic process pattern, caudal ramus configuration, antennary armature and P1 morphology. It is allocated to a new genus and species, Juxtaramia polaris. Both sexes of Arthropsyllus serratus are redescribed from new and existing material collected in southern Norway. Re-examination of Norman's (1911) material from the Firth of Clyde did not provide any conclusive evidence to maintain A. serratus spinifera as a valid subspecies. A. australis is transferred as the type species of a new genus Breviconia, since it deviates significantly from the revised diagnosis of Arthropsyllus. Laophontodes echinatus Brady, 1918 is regarded as species inquirenda in Breviconia. A new genus and species, Uptionyx verenae, is described from a hydrothermal vent of the Juan de Fuca Ridge, northeastern Pacific Ocean. Parsimony analysis of the Ancorabolus-group identifies Arthropsyllus as the most primitive offshoot and Juxtaramia-Ancorabolus as the terminal clade with both Uptionyx and Breviconia diverging from intermediate nodes. Evolution in the group is typified by progressive elaboration and ramification of integumental processes on the cephalothorax and free body somites, culminating in the complex body ornamentation of the most advanced genus Ancorabolus. Distribution records of all five genera are compiled