Paranesidea

Maddocks, Rosalie F., 2015, New and poorly known species of Bairdoppilata and Paranesidea (Bairdiidae, Ostracoda) from French Frigate Shoals and O’ahu, the Hawaiian Islands, Zootaxa 4059 (2), pp. 277-317 : 314

Paranesidea sp. 2

( Fig. 21 )

Material. One adult female.

Dimensions. Adult female 3961F, carapace fragmentary and dimensions approximate: Length 916 µm, height 630 µm. See also Table 1 and Figures 2 and 4 .

Descriptive comments. Carapace apparently smooth; rounded-subhexagonal (bairdian) in lateral outline, with narrowly arched dorsal margin, indistinct anterodorsal and posterodorsal corners; greatest height located at 0.47 of length; anterodorsal brim located at 0.04 of length and 0.60 of height; posterodorsal brim located at 0.98 of length and 0.43 of height; highest point of ventral indentation located at 0.46 of length and 0.07 of height. Slope (measured from horizontal) of anterodorsal margin 39o, of posterodorsal margin 51o, of dorso-caudal margin 17o, of hinge 4o. Distinct caudal process. No patch pattern or pigmentation is visible in the decalcified carapace. The assignment to Paranesidea is based on the moderately pectinate character of the fused antennal claw, as usual for females of this genus. The apparently smooth surface with a reticulate pattern of tiny micropapillae (which may reflect cells in the underlying epidermis) is noteworthy.

Comparisons. The carapace dimensions of P. sp. 2 would fall in the upper part of the size range for P. spongicola and close to that of P. onslowensis . It is much smaller than P. poseidonicola and it lacks the expanded caudal flange and marginal denticles of that species. The upright, distinctly caudate shape cannot be equated to any of the species of “ Bairdia ” or Paranesidea described by Holden (1967, 1976) from Hawaii or Lower Miocene of Midway.

Figures

FIGURE 2. Carapace dimensions for the species of Bairdoppilata and Paranesidea described here. The assemblages of B. scaura, B. sp. 2 and B. sp. 3 each include two late instars as well as adults; the others include only adult specimens. See also Table 1.

FIGURE 4. Carapace dimensions for 15 shallow-water species of Bairdoppilata. These data include adults only, of species for which the soft parts have been described. See also Table 2.

FIGURE 21. P aranesidea sp. 2; all female specimen 3961 F. A, left exterior of whole animal before dissection, filled with secondary concretions; B – D, fringed claws of palp and masticatory processes of maxilla; E – F, distal claws of antenna; G, pectinate distal claw of mandible palp; H – I, genital lobes; J, detail of Fig. I showing longitudinal striations within tubes; K – L, hinge region of carapace, showing straight connecting ribbons and micropapillate surface texture; M, anterior margin with RPC, selvage, flange, pappose and eyelash setae; N – Q, details of Fig. M at high and low focus, to show pappose setae; R, fragment of decalcified carapace, showing NPC and reticular pattern of micropapillae; S, detail of left exterior before dissection, with setae and micropapillae. Scale bar = 50 µm.