Eucalathis magna Cooper, 1981

Bitner, Maria Aleksandra & Logan, Alan, 2016, Recent Brachiopoda from the Mozambique-Madagascar area, western Indian Ocean, Zoosystema 38 (1), pp. 5-41 : 18

Eucalathis magna Cooper, 1981

( Fig. 10 A-D)

Eucalathis magna Cooper, 1981a: 17 , pl. 1, figs 1-6. — Zezina 2010: 1187.

MATERIAL EXAMINED. — South Madagascar. ATIMO VATAE, stn DW 3529, 1 bivalved specimen.

DEPTH RANGE. — 402- 207 m.

MEASUREMENTS. — Length 13.4 mm, width 10.7 mm, thickness 4.8 mm.

REMARKS

Species of the genus Eucalathis are common in all the oceans of the world and range greatly in depth. Six species have been recorded from the Indian Ocean : E. rotundata Cooper, 1981 ; costellata Cooper, 1981; fasciculata Cooper, 1973; magna Cooper, 1981 ; murrayi (Davidson, 1878) ; and rugosa Cooper, 1973 ( Logan 2007) . E. magna is very rare in the investigated material, represented by only one specimen. It was originally described, also based on one specimen, from the West of Heard Island at a depth of 790 m by Cooper (1981a). The present finding extends its geographical range.

This species is characterized by a large size for the genus and almond-like outline. Both in outline and ornamentation E. magna strongly resembles Terebratulina species. Cooper (1981a: 17) indicated the absence of deltidial plates, however, although minute they are present, both in the specimen from off South of Madagascar and the holotype.

Figures

FIG. 10. — A-D, Eucalathis magna Cooper, 1981, ventral, dorsal, lateral and anterior views of complete specimen (MNHN IB-2013-60), South Madagascar, sector of Manantenina, stn DW 3529, 402-407 m; E-O, Eucalathis daphneae n. sp., North-West Madagascar, MIRIKY, SEM: E, inner view of ventral valve (MNHN IB- 2013-62), paratype, West of Cap d’Ambre, stn DW 3196, 238-249 m; F-J, dorsal view of complete specimen, enlargement of umbonal part (G) and anterior view to show rounded ribs (H), and inner view of dorsal valve (I, J) of the same specimen to show cardinalia and loop, holotype (MNHN IB-2013-61), West of Nosy Be, stn DW 3234, 187-247 m; K-O, inner view of dorsal valve (MNHN IB-2013-63), enlargement (L) and tilted (M) views of posterior part,and a fragment of incomplete transverse band (O), paratype, stn DW 3196, 238-249 m. Scale bars: A-D, 5 mm; E, F, H, I, K, 2 mm; G, J, L,1 mm; M, 500 µm; O, 200 µm.