Abyssocythere squalidentata (Brady, 1880)

Brandão, Simone N., Stuhlmann, Annalena, Vital, Helenice & Brandt, Angelika, 2016, Biogeography of Abyssocythere and Dutoitella (Ostracoda), with descriptions of three new species, Zootaxa 4139 (3), pp. 391-418 : 399

Abyssocythere squalidentata (Brady, 1880) nomen dubium

( Figures 1 , 7 , Table 1)

1880 Cythere squalidentata Brady : 110, pl. 23.8a–8d

1971 Abyssocythere squalidentata ; Benson: 8, pl. 1.9

1976 Cythere squalidentata Brady ; Puri & Hulings: 289, pl. 16.3–16.5

Material. Lectotype NHM 81.5.29.A (SNB added the “A” after the collection number): One closed, Subrecent carapace (i.e. left and right valves) on a white, paper micropalaeontological slide labelled “173, Cythere squalidentata Brady, H. S. Puri 9/67, Photo 386–388, T, Lectoholotype, 102, 1 RLV, “Challenger”, No. 323, Depth 1900, tow net, 81.5.29.A”—This specimen was studied and illustrated with an optical microscope by Benson (1971, pl. 1.9) and Puri & Hulings (1976: 289, pl. 16.3–16.5).

Stratigraphic and geographical occurrence. (locality 7 in Fig. 1 and Tab. 1) Quaternary. Southwestern Atlantic. 3475m depth (only known from the type locality).

Type locality (Brady 1880: 110). Subrecent. Southwestern Atlantic. Challenger Expedition 1873–1876, station 323, sounding 473, 35°39'S, 50°47'W, Rio de la Plata to Tristan da Cunha, 1900 fathoms (3475m).

Measurements. LECTOTYPE (7), LV length 0.39mm; height 0.28mm. RV length 0.39mm; height 0.28mm.

Remarks. Benson (1971) considered this species a nomen dubium, since the lectotype is a juvenile (very small size and much higher anteriorly). We did not separate its two valves in order to observe the inner lamella (which indicates the instar stage of an ostracod), because of its very small size and the consequent risk of damaging it. Herein, we provide the first SEMs of the lectotype of this species ( Fig. 7 ).

A–B, lectotype (NHM 81.5.29.A): A, right valve; B, left valve.

Figure license: Creative Commons Attribution-Non Commercial-Share Alike (CC BY-NC-SA). Copyright: Trustees of The Natural History Museum, London.

Figures

FIGURE 1. Geographical distribution of Abyssocythere Benson, 1971 in the different geological epochs or stages (for a complete list of references used for this Figure see Supplementary material 1).

FIGURE 7. External views of the left and right valves of the lectotype of Abyssocythere squalidentata (Brady, 1880). Type locality (Brady, 1880: 110). Subrecent. Southwestern Atlantic. Challenger Expedition 1873 – 1876, station 323, sounding 473, 35 ° 39 ' S, 50 ° 47 ' W, Rio de la Plata to Tristan da Cunha, 1900 fathoms (3475 m).