Thecidellina minuta Cooper, 1981

Bitner, Maria Aleksandra, 2009, Recent Brachiopoda from the Norfolk Ridge, New Caledonia, with description of four new species, Zootaxa 2235, pp. 1-39 : 18

Thecidellina minuta Cooper, 1981

( Fig. 13 )

Numerous specimens of T. minuta were found in only one sample, from Crypthelia seamount ( Tables 1, 2) at 267 m ( Fig. 14 ). This thecidellinide is characterized by its very small size and the presence of pseudodeltidium. The brachial cavities are covered by reticulated canopying spicules ( Fig. 13 D-I). Because of its very small size the species might easily be taken for a juvenile of Thecidellina maxilla ; however, the presence of a pseudodeltidium (observed in all ontogenic stages, Jana Hoffmann pers. comm.) clearly distinguishes T. minuta from T. maxilla . This is the first record of T. minuta from the Pacific; so far it is known only from the western part of the Indian Ocean ( Cooper 1981; Zezina 1994; Lee & Robinson 2003).

Figures

FIGURE 13. Thecidellina minuta Cooper, 1981, Norfolk Ridge, Norfolk 1 Stn DW 1723, 266 – 267 m: A, dorsal view of complete specimen, visible pseudodeltidium, MNHN BRA- 3177; B, C, inner view of ventral valve and titled enlargement to show hemispondylium in form of two plates, MNHN BRA- 3178; D, inner view of dorsal valve, visible interconnected canopying spicules, MNHN BRA- 3179; E, F, inner and posterior views of dorsal valve, visible brachial bridge supported by a slender calcitic pole, MNHN BRA- 3180; G-I, inner, posterior and lateral views of dorsal valve, visible interconnected canopying spicules and a slender pole, MNHN BRA- 3181. All SEM.

FIGURE 14. Depth ranges of particular brachiopod species collected during the Norfolk 1 and Norfolk 2 cruises to the Norfolk Ridge, New Caledonia.