Paranoplodelphys, Boxshall, Geoff A. & Marchenkov, Andrey, 2007

Boxshall, Geoff A. & Marchenkov, Andrey, 2007, A revision of the Brementia - group of genera (Copepoda: Notodelphyidae), with descriptions of a new genus and four new species, Zootaxa 1459, pp. 37-68 : 48-49

Paranoplodelphys n. gen.

Diagnosis: Body highly transformed; lacking external expression of body segmentation. Cephalosome with broad, strongly-convex frontal margin bearing paired antennule vestiges ventrolaterally. Rostrum lacking. Labrum forming elongate, posteriorly-directed lobe. Metasome extending posteriorly beyond end of dorsally located urosome. Urosome incorporating caudal rami, presented by caudal setae. Surface of body, labrum and legs densely ornamented with surface setules.

Antennules present as pair of wrinkled lobes originating close to labrum on ventral side of cephalosome. Antenna absent. Oral region lacking any vestiges of mouthparts. Leg 1 biramous; rami represented by unsegmented, rounded lobes; exopodal lobe reduced, laterally-directed; endopodal lobe large. Leg 2 uniramous, a simple lobe. Legs 3 and 4 absent. Leg 5 lobe bearing 2 setae.

Type species: Paranoplodelphys simplex n. gen. et n. sp. (by original designation)

Etymology: The genus name refers to the similarity between the new genus and Anoplodelphys .

Remarks: The phylogenetic analysis presented below ( Fig. 14 ) places this new species as the sister-taxon to a lineage comprising Achelidelphys , Cephalodelphys and Syndelphys . It does not cluster with Anoplodelphys species but it lacks the stellate body form (defined by the apomorphic states of characters 1 and 2) of the Achelidelphys – Cephalodelphys – Syndelphys lineage. A new genus is established to accommodate this new species which represents the most extreme reduction known within the lineage. It retains only the antennules on the cephalosome and all other cephalosomic limbs are lost. The legs are also reduced: leg 1 is the only biramous leg, leg 2 is uniramous and legs 3 and 4 are lost. Combined with all these reductions is the retention of a well-defined leg 5, which is apparently lost in many of the less reduced relatives.

Figures

FIGURE 14. Majority rule consensus tree showing estimated relationships between genera of Brementia - group with the family Notodelphyidae. The tree is the consensus of 10 equally parsimonious trees (branch length = 34). Values given above line are bootstrap values. Numbers below the line indicate the characters supporting the main clades. * Anoplodelphys incertae represents three taxa: A. incertae, A. galli and A. cf. galli, all of which have identical scores for the characters used in the analysis. Similarly, Achelidelphys chengae also represents Achelidelphys papuensis n. sp. which has identical scores for the characters used.