Bythocypris richarddinglei
LV outline sub-rectangular; with smoothly arched dorsal margin; steep posterodorsal margin; broadly rounded anterior margin; slightly concave ventral margin; maximum height posterior to mid-length. RV subtrapezoidal; with fairly straight anterodorsal margin; sinuate posterodorsal margin; truncate anterior margin; concave ventral margin; maximum height at mid-length. LV and RV with obtuse posterior angle. Maximum length inferior to mid-height. Calcified inner lamella fairly narrow; zone of concrescence very narrow, with numerous straight marginal pore canals. Adductor muscle scars bythocypridid, occupying less than 1/3 of valve height.
Antennula very robust; with relatively short and very strongly sclerotized setae; podomeres II and III fused; chaetotaxy. Antenna stout; with short podomeres III, IV and VI; exopodite with 2 long and 1 tiny setae; podomere VI wider than long, with 1 long and 1 medium-sized claws, 1 tiny seta, and 2 medium-sized setae. Mandibula with 3 feathered setae on the exopodite; masticatory process with 1 or 2 bifurcate and 3 or 4 trifurcate teeth and several short setae. MaxilluIa with 7 strahlen and 24 or 25 feathered setae; ventral endite with 2 ventral setae and several broad, feathered, distal claws; other endites with 1 ventral seta each plus several simple distal setae; all setae of palp not feathered. Vibratory plate of fifth limb with 4 or 5 long strahlen and 10 medium-sized setae; podomeres of fifth to seventh limbs robust, with long and feathered terminal claws; exopodite of sixth and seventh limbs with or without 1 tiny seta. Furca with 2 short, 1 medium-sized, and 2 long feathered setae; one tiny seta between furcal rods. Genital lobe sub-oval with tubular internal process.
LV outline sub-rectangular, with smoothly arched dorsal margin, maximum height posterior to mid-length. RV subtrapezoidal with fairly straight anterodorsal margin and highly arched posterodorsal margin. LV and RV with slightly concave ventral margin and obtuse posterior angle. Podomere VI of antenna wider than long, with 1 long and 1 medium-sized claws, 2 medium-sized setae and 1 tiny seta. Maxillula with 7 strahlen and 24 or 25 feathered setae. Vibratory plate of fifth limb with 4 or 5 strahlen and 10 setae. Furca with 2 short, 1 medium-sized and 2 long feathered setae. Genital lobe suboval with tubular internal process.
Bythocypris reniformis Brady, 1880 sensu Puri and Hulings (1976: Pl. 2.7–10, Fig. 1).
Holotype, LV–L 1.27mm, H 0.73mm; RV–L 1.26mm, H 0.64mm.
Paratypes, LV–A F L 1.21–1.26mm, H 0.70–0.72mm; (A-1) L 1.02mm, H 0.60mm.
For the soft part anatomy, I follow Horne et al., 2002 (Horne DJ, Cohen A, Martens K. 2002. Taxonomy, morphology and biology of Quaternary and living Ostracoda. In: Holmes JA, Chivas AR, editors. The Ostracoda. Applications in Quaternary Research. Washington, DC: American Geophysical Union. p 5-35.).
We use the following terms for the limbs/furca from anterior to posterior with alternative names in parenthesis:
antennula (antenna I, Aa, AI, first antenna)antenna (antenna II, AII, Au, second antenna)mandibula (mandible, Md)Maxillula (first maxilla, maxilla I, maxillule, MxI, Mxu)Fifth limb (ApV, Appendage V, first thoracic leg, maxilla, maxilla I, MxI, Mxu, maxilliped, clasper (for males), P1, second maxilla, walking leg)Sixth limb (ApVI, Appendage VI, first thoracic leg, second thoracic leg, P2, walking leg)Seventh limb (ApVII, Appendage VII, cleaning limb, P3, second thoracic leg, third thoracic leg, walking leg)Male copulatory limb (eighth limb, hemipenis, uropod). Whether the Male copulatory limb is homologous to a crustacean limb remains controvertial.Furca (caudal rami, Fu, furcal rami, uropods). The homology of the podocopan furca (anterior to the anus) to a myodocopan furca (posterior to the anus) remains controversial. Similarly, the homology of the ostracod furca to the furca of other crustaceans remains controvertial.
Antennula 1(0/0), 2(0/.1)+3(0/.2), 4(1/0), 5(.2/.3), 6(.2/.3), 7(0/0:5). Antenna 1(0/0:2i), 2(.1/0:1i), 3(0/.2.1.1), 4(0/.2r.2), 5(.1.1c./ .1.1), 6(0/0:1r,1c,2,1c). Mandibula palp 1(.1/.1:1i), 2(.1./.1:1i), 3(.5./.1:2-3i), 4(.2./0:3-4). Maxillula palp (.1.1.1./.2.:1c). Fifth limb 1(.1.1.0-2/0:1i,1), 2(.2/0), 3(.1/0), 4(.1/0), 5(0/0:2,1c). Sixth and seventh limb 1(.1.1.1/0:1i), ApV-VII-2(.2/0), 3(.1/0), 4(.1/0), 5(0/0:2,1c).
Chaetotaxy formula follows Schornikov and Keyser (2004, The morphology and classification of Paradoxostomatinae (Ostracoda) from the nearshore zone of Madeira and the Canary Islands. Revista Española de Micropaleontologia 36: 57-81.) : "Figures without parentheses = podomeres numbered from proximal to distal; + = junction of podomeres. Figures within parentheses = number of setae: numerator = setae on dorsal margin; denominator = setae on ventral margin; integer figures = lateral, medial or apical armature elements, from dorsal to ventral. Figures within parentheses without indexes = normally development setae; r = rudimentary; c = claw-shaped seta or claws; s = sensory seta; p = plumose seta or ray; re = reflexed seta or ray; a = atriumwards ray; t = tooth or tooth-shaped seta; l or m = lateral or medial seta. A dot indicates the presence of an interval between setae or between podomere ends; a colon indicates apical, lateral or medial setae; hyphen indicates variable elements. Commas are used for the sake of clarity e.g. to separate symbols by unarmed podomeres or setae without indexes."
(see an example of the chaetotaxy formula in the figure "EXAMPLE CHAETOTAXY" in this species page)
5 live specimens.
Holotype: 1 A F (SNB 0253), ANDEEP III, # 16–11, ZMH K-41289.
Paratypes: 1 A F (SNB 0095), ANDEEP III, # 16–11, ZMH K-41290;
1 A F (SNB 0093), ANDEEP III, # 16–7, ZMH K-41291;
1 A F (SNB 0250), 1 (A-1) (SNB 0252), ANDEEP III, # 16–10–S, ZMH K-41292.
A, adult; (A-1), (A-2), (A-3), juvenile instars; E (after a station number), epinet of the epibenthic sledge; F, female; H, Height; L, length; LV, left valve; M, male; RV, right valve; S (after a station number), supranet of the epibenthic sledge; SNB, specimen number as catalogued by the Brandão, S. N. (throught this number, it is possible to assign correctly the valves of a single specimen kept in a micropaleontological slide to their dissected appendages in a glass slide); V, valve; ZMH, Zoologisches Institut und Museum, University of Hamburg (Germany); ZMH K-, abbreviation of the Crustacea collection of the Zoologisches Institut und Museum, University of Hamburg (Germany); #, station number.
2008 Bythocypris richarddinglei Brandão, 2008: 425-428, Figs. 18, 37, 38.
In honour of Dr. Richard V. Dingle for his important contribution to the knowledge of deep-sea fossil and recent Ostracoda, especially from the south-eastern Atlantic.
The valves of Bythocypris richarddinglei Brandão, 2008 differ from Bythocypris reniformis Brady, 1880 sensu Puri and Hulings (1976: Pl. 2.7–10, Fig. 1) and B. praerenis Brandão, 2008 by the more rounded outline, greater height in relation to length, and larger size (LV L: 1.21 to 1.27mm, instead of 1.09mm) of the former species. The valves of Bythocypris [sic] reniformis recorded by Maddocks (1969, Fig. 45.J–M) from the south-western Atlantic (Albatross, #2763, 24°17’S, 42°48’30’’W, 1227m) are larger (LV L: 1.52–1.61mm), and more subtriangular than those of the new species described herein, with the maximum height of LV and RV at mid-length, instead of posterior to it. Bythocypris [sic] reniformis recorded by Maddocks (1969, Fig. 45.N–U) from the Mozambique Channel, Southwestern Indian Ocean (R. V. Anton Bruun, cruises 7 and 8, #365D, 23°20’S, 43°33E, 695-475m) present more similar, rectilinear outline to B. richarddinglei Brandão, 2008 , but a more arcuate LV dorsal margin, and more rounded RV dorsal margin. B. eltanina Maddocks, 1969, B. spiriscutica Maddocks, 1969, B. promoza Maddocks, 1973, Bythocypris mozambiquensis Maddocks, 1969, and B. polarsterni Brandão, 2008 are more subtriangular than Bythocypris richarddinglei Brandão, 2008 Bythocypris elongata Brady, 1880, Bythocypris prolata Maddocks, 1969 are more elongated than B. richarddinglei Brandão, 2008 Bythocypris affins affins Brady, 1886 (sensu Brady & Norman 1889: 242) is smaller and more elongate, with a more smoothly rounded posterior angle. Bythocypris affins madagascarensis Maddocks, 1969 is higher in relation to length and with the maximum height of LV at mid-length instead of conspicuously posterior to it.
Cape Basin, Southeastern Atlantic, 4686 to 4723m.
Brandão (2008)
Brandão, S. N., 2008. New species of Bairdioidea (Crustacea, Ostracoda) from the Southern Ocean and discussions on Bairdoppilata simplex (Brady, 1880), ?Bairdoppilata labiata (Müller, 1908) and Bythopussella aculeata (Müller, 1908). Zootaxa, 1866: 373–452,
(this publication can be freely downloaded from http://www.mapress.com/zootaxa/2008/f/zt01866p452.pdf)