Fabaeformiscandona condylea, Smith & Janz, 2008
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publication ID |
https://doi.org/ 10.1080/00222930802361030 |
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persistent identifier |
https://treatment.plazi.org/id/6530807D-EC3B-FFB1-AFF1-FB04FDE1FE0E |
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treatment provided by |
Carolina |
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scientific name |
Fabaeformiscandona condylea |
| status |
sp. nov. |
Fabaeformiscandona condylea sp. nov.
( Figures 8 View Figure 8 D–F, 11 and 12)
Type locality
Eastern shore of north basin of Lake Biwa, locality 41 (35 ° 13957.50N; 136 ° 10906.40E), depth 0.25 m, coarse, poorly sorted sandy beach with rounded pebbles and a little mud.
(LBM 1430003308); (I) dorsal view of female, anterior to right (LBM 1430003308). (J–L) Fabaeformiscandona yajimae sp. nov. (J) Male, whole carapace, right lateral view (LBM 1430003312); (K) female, whole carapace, right lateral view (LBM 1430003313); (L) dorsal view of female, anterior to right (LBM 1430003313). Scale bar below L represents 447 Mm for A–C, 288 Mm for D–F, 500 Mm for G–I, and 532 Mm for J–L.
Type material
Holotype LBM 1430003303 View Materials , male, appendages mounted on a glass slide, valves stored in a micropalaeontological cavity slide . Allotype LBM 1430003306 View Materials , female, appendages mounted on a glass slide, valves stored in a micropalaeontological cavity slide . Paratype LBM 1430003305 View Materials , female, appendages mounted on a glass slide, valves stored in a micropalaeontological cavity slide . Paratype LBM 1430003304 View Materials , male, appendages mounted on a glass slide, valves stored in a micropalaeontological cavity slide . Paratype LBM 1430003302 View Materials , male, appendages mounted on a glass slide . Paratype LBM 1430003299 View Materials , male, whole carapace stored in a micropalaeontological cavity slide (locality 9) . Paratype LBM 1430003301 View Materials , female, whole carapace stored in a micropalaeontological cavity slide .
Derivation of name
From the Latin condylus meaning knuckle or fist, as the hemipenis looks like a fist with a thumb protruding (the a lobe) ( Figure 12C View Figure 12 ).
Diagnosis
Carapace small, dorsal margin slightly curved in male, straight in female. In female ventral and dorsal margins sub-parallel. Dorsal view very compressed, with subparallel lateral margins. G2 claw of female An2 half the length of G1. L6 elongate, L7 five-segmented. Hp with large, curved a lobe protruding from distal end of Hp. FRO projection small and elongate. UR claws sub-equal in length, seta Sa very small.
Description
Male carapace length 506–622 Mm, height 258–317 Mm, H/L50.49–0.51, female length 483–531 Mm, height 222–250 Mm, H/L50.46–0.47. Male carapace maximum height at posterior third marked by dorsal hump. Dorsal margin straight anteriorly of maximum height, sloping towards anterior margin. Ventral margin slightly concave, anterior margin slightly less inflated than posterior margin. Dorsal view of female very compressed, with sub-parallel lateral margins, and posterior margin slightly more rounded than anterior margin. Calcified inner lamella wide anteriorly and relatively wide posteriorly. Female carapace sub-rectangular with dorsal and ventral margins sub-parallel. Female left valve with small, but well-defined anterodorsal flap, and ill-defined, very shallow posterodorsal flap. Anterior margin slightly more inflated than posterior margin. Surface of valves smooth, colour translucent white.
An1 with eight segments, first two of which partially fused, but possibly with some articulation. Dorsal seta on first segment relatively long, second segment with short dorsal seta and two long ventral setae. Third segment quadrate with short seta on dorsal–apical corner. Fourth segment quadrate with tiny seta on dorsal–apical corner. Fifth and sixth segments each with two long dorsal–apical setae and one short ventral–apical seta. Seventh segment with two long, one medium-length and one short apical setae. Eighth segment with two long setae, one short seta and aesthetasc ya.
An2 with long and slender Y aesthetasc. Male Gm claw approximately half the length of GM, setae t2 and t3 both terminating with disc-shaped structures. Female with G2 claw approximately half the length of G1 and Gm slightly shorter and more slender than GM.
Md with 3+1+beta setae on second segment of palp.
L5 with asymmetrical male palps, both widening distally. Right palp with rounded end terminating with small finger-like projection on inner edge. Left palp less inflated distally than right one, and terminating with longer and thicker fingerlike process compared with right.
L6 very elongate, especially second segment. Setae e and f very short, neither reaching point of mid-length of next segment. Claw h2 long and slender.
L7 five-segmented with very long h3 seta, shorter h2 seta, and short h1 seta.
UR relatively short and stubby, with tiny Sa seta. Claws Ga and Gp almost equal in length.
Hp with rounded basal capsule supporting three distal lobes. Innermost lobe (a lobe) largest, curving towards inner edge and with rounded end. Middle and outer lobes both with rounded ends, outermost lobe smallest. m process not observed, possibly reduced.
FRO rounded with very small, finger-like posterior projection with rounded end.
Remarks
The females of this species are similar to those of Fabaeformiscandona breuili (Paris, 1920) in terms of carapace shape and FRO projection, but there are significant differences in the other appendages. Fabaeformiscandona breuili has only four segments in the L7 (five in F. condylea sp. nov.), much longer claws on the An2, longer e and f setae on the L6, and a much longer Sp seta on the UR compared with F. condylea sp. nov. Additionally, F. condylea sp. nov., with 3+1+beta setae on the Md palp, belongs to the fabaeformis -group, whereas F. breuili belongs to the breuili - group, which has a Md with 4+1+beta setae. Males of F. breuili are unknown. Although considerably larger at 700–810 Mm in length, females of Fabaeformiscandona brevicornis (Klie, 1925) are also similar to those of F. condylea sp. nov. in terms of carapace shape. However, F. brevicornis has a much longer g seta on the L7, a much longer G2 claw on the An2 and longer e and f setae on the L6 compared with those of F. condylea sp. nov. Additionally, the Md palp of F. brevicornis has 4+1+beta setae indicating that it belongs to the acuminata -group and not the fabaeformis -group. The males of F. brevicornis are unknown. Another species that shows a remarkable similarity to F. condylea sp. nov. in carapace shapes of both sexes, the male fifth limb palps, the reduced setae on the L6, the morphology of the UR, and very small FRO projection, is Schellencandona belgica (Klie, 1937) . However, S. belgica has a Zenker organ with 4+2 rosettes (5+ 2 in Fabaeformiscandona species), and a considerably different Hp morphology. The very close similarity of some features of these two species that belong to different genera is possibly a result of convergent evolution in an interstitial environment.
Fabaeformiscandona condylea sp. nov. was found interstitially twice, in a beach of poorly sorted sand and pebbles, and in an angular gravel and pebble beach. Localities 9 and 41 in Figure 1 View Figure 1 .
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