Eurypylus eagari Kornicker & Iliffe 2000

Eurypylus eagari

ETYMOLOGY.—Named for Dr. Stephan Eagar, ostracodologist.

HOLOTYPE.—USNM 194478, ovigerous female on slide and in alcohol.

TYPE LOCALITY.—Sta 94-018, transect AA, Exuma Sound, Bahamas, depth 67 m.

PARATYPES.—None.

DISTRIBUTION.—Collected only at type locality.

DESCRIPTION OF ADULT FEMALE (Figures 30–32).—Carapace oval in lateral view with projecting caudal process, and lateral projection at valve midheight extending posteriorly just past valve edge (Figure 30). Location of incisur indicated by indentation in lateral surface of anterior margin of valve at about midheight, but no indentation present in valve edge.

Ornamentation (Figure 30): Surface with lateral ribs both dorsal and ventral to valve midheight; a peripheral rib located well in from valve edge and with small riblets extending from rib to valve edge. Surface with numerous oval fossae with minute papillae on bottom. Bristles, some with broad base, numerous along valve edge and sparse on lateral surface. Ventral and anterior margins scalloped. Valves without gel-like coating.

Infold: Small bristle near inner margin of anterior infold just ventral to incisure. Infold of caudal process with 9–11 small bristles and with few smaller bristles along inner edge of infold (Figure 32i). Two setal bristles present dorsal to caudal process at about valve height measured from caudal process.

Selvage: Wide lamellar prolongation along anterodorsal, anterior, anteroventral, and ventral edges of valves; lamellar prolongation extending well past tip of caudal process; outer edge of anteroventral lamellar prolongation with fringe of closely spaced coarse spines; fringe along anterior and anterodorsal lamellar prolongation with slenderer spines; edge of ventral and posterior lamellar prolongation without spines. (Poulsen (1965:48) stated that the outer edge of the selvage of the Sarsiellidae is without a fringe of hairs that is characteristic of the Philomedinae and Rutidermatidae. Thus, the fringe of hairs along the outer edge of part of the lamellar prolongation of E. eagari is unusual, and has not previously been reported on other Sarsiellinae, but has been reported on species of Dantyinae by Kornicker and Cohen (1978:497).)

Carapace Size (length, height in mm): USNM 194478, 0.64, 0.52.

First Antenna (Figure 31 c,d): 1st joint bare. 2nd joint with dorsal spines and dorsal bristle with indistinct spines. 3rd and 4th joints fused; 3rd joint with 2 bristles (1 dorsal, 1 ventral (ventral bristle missing on right limb of USNM 194478; the bristle shown dashed on illustrated right limb (Figure 31c) is based on length of bristle of left limb)); 4th joint with 3 bristles (1 dorsal, 2 ventral). 5th joint with long ventral bristle with minute spine at midlength and 1 terminal spine. 6th joint minute, fused to 5th joint, with small terminal medial bristle. 7th and 8th joints fused. 7th joint: a-bristle short; b-bristle about length of a-bristle; c-bristle long. 8th joint: d- and e-bristles equilength, slightly shorter than bristle of 5th limb, bare with blunt tips; f-bristle claw-like in proximal half with curved and oblique cross-sutures, and bristle-like in distal half with closely spaced rings (proximal end of distal half narrower than distal end of proximal half); g-bristle similar to f-bristle, but slightly longer.

Second Antenna (Figure 31c,e): Protopodite bare. Endopodite 2 jointed: 1st joint with 1 or 2 proximal ringed anterior bristles; 2nd joint with terminal bristle (with slender drawn-out tip) slightly longer than bristles of 1st joint (endopodite could be interpreted to be 1-jointed if terminal protuberance considered part of 1st joint). Exopodite: 1st joint with small recurved terminal medial bristle with blunt tip; bristles of joints 2 and 3 with slender proximal ventral spines and distal natatory hairs; bristles of joints 4–8 with natatory hairs, no spines; 9th joint with 2 bristles (dorsal short bare, ventral long with few proximal hair-like ventral spines and natatory hairs).

Mandible (Figure 31f–h): Coxale endite consisting of medial spine in proximal ventral corner; ventral margin of coxale with hairs; medial surface near ventral margin with few indistinct small spines. Basale: ventral margin with 4 small medial and 2 small lateral bristles; dorsal margin with 2 small indistinct bristles (1 near midlength, 1 subterminal). Exopodite absent. 1st endopodial joint with medial spines, a row of slender medial spines along distal edge near dorsal margin, a few indistinct terminal spines on dorsal margin, and stout bare ventral claw. 2nd endopodial joint with small dorsal bristle and stout bare ventral claw. 3rd endopodial joint with stout terminal claw and 2 minute bristles (1 ventral, 1 dorsal).

Maxilla (Figure 32a,b): Precoxale and coxale with long hairs. Coxale with bare dorsal bristle. Endite I with 6 bristles (2 claw-like pectinate); endite II with 4 bristles; endite III with 5 bristles (2 proximal, 3 terminal). Transparent thumb-like flap projects from basale (or from near base of endites). Basale with bristle near exopodite. Exopodite with 3 bristles (1 long, 2 short). 1st endopodial joint with pectinate alpha- and beta-bristles. 2nd endopodial joint with 2 a-bristles, 1 c-bristle, and 5 pectinate end bristles (middle bristle shortest, anterior bristle ringed).

Fifth Limb: Epipodite with about 22 bristles. Single endite with 1 small bristle (Figure 32d). 1st exopodial joint with 2 bristles (Figure 32e); 2nd exopodial joint with 3 terminal bristles; 3rd exopodial joint with 1 bristle on outer lobe; fused 4th and 5th joints with 2 terminal bristles; exopodite with long hairs. (A small bristle illustrated by dashes on folded limb shown in Figure 32e could be either the endite bristle or a bristle on an exopodial joint.)

Sixth Limb (Figure 32f): Single endite with 1 terminal bristle and 1 or 2 shorter medial bristles. End joint with 9 or 10 bristles with short spines and 2 broader plumose posterior bristles; medial surface and posterior margin of end joint with long hairs.

Seventh Limb (Figure 32c,g): Limb with 8 cylindrical bristles: 2 in proximal group (1 on each side) each with 2 bells; 6 in terminal group (3 on each side) with either 1–4, or 2–4 bells; clappers of terminal bells unusually long. Terminus with opposing combs, each with 2 or 3 minute teeth.

Furca (Figures 31i,l, 32c,h): Each lamella with 6 claws: claws 1 and 2 primary and nonarticulated; claws 3–6 secondary and articulated. Claws 1–5, and possibly 6, with teeth along posterior margin; a few teeth on claws 1 and 2 stouter than others. Long slender medial spines near base of claw 1; slender spines present along margins of lamellae following claws. Right lamella anterior to left by width of base of claw 1.

Bellonci Organ (Figure 31j): Elongate with suture proximal to midlength and rounded tip with minute node.

Eyes: Medial eye bare unpigmented (Figure 31f). Lateral eye unpigmented, smaller than medial eye, with 5 amber-colored divided ommatidia (Figure 31j,k).

Upper Lip: Indistinct, projecting anteriorly, bare.

Posterior of Body (Figures 31l, 32c,h): With few spines dorsal to dorsal end of girdle.

Genitalia (Figures 31m, 32c): Rimmed oval on each side anterior to furca.

Y-Sclerite (Figure 31l): With ventral branch typical for family.

Eggs: USNM 194478 with 2 oval eggs in marsupium (1 shown in Figure 31a). Maximum lengths of each egg (mm): 0.15, 0.17.

COMPARISONS.—The presence of secondary claws following the primary claws on the furca places E. eagari in the Eurypylus petrosus group of Kornicker (1996, table 3). The only species in that group having a total of six claws is E. darwinensis Kornicker, 1996. The caudal process of the female E. eagari projects farther posteriorly than that of E. darwinensis, and the endopodite of the female 2nd antenna of E. darwinensis is without a terminal bristle. Eurypylus eagari is the only species of the sarsiellinae reported to have spines along the outer edge of the lamellar prolongation of the selvage.

This family contains two subfamilies: Rutidermatidinae Brady and Norman, 1896, and Metaschismatinae Kornicker, 1994.

Rutiderma Brady and Norman, 1896

TYPE SPECIES.—Rutiderma compressa Brady and Norman, 1896.

COMPOSITION AND DISTRIBUTION.—This genus is cosmopolitan between the latitudes of 45°N and 53°S, at depths from intertidal to 317 m (questionably to 1834 m), and contains about 31 species (Cohen and Kornicker, 1987; Kornicker, 1992, 1996).