Aulites crosnieri, Bitner, Maria Aleksandra, 2009

Bitner, Maria Aleksandra, 2009, Recent Brachiopoda from the Norfolk Ridge, New Caledonia, with description of four new species, Zootaxa 2235, pp. 1-39 : 21-23

Aulites crosnieri sp. nov.

( Fig. 5 A–J)

Material examined. Norfolk 1 cruise, Crypthelia seamount, Stn DW 1724, three complete specimens.

Holotype. The specimen in Figure 5 F–J ( MNHN BRA- 3136).

Paratypes. The specimens in Figure 5 A–E ( MNHN BRA- 3137–3138).

Type locality. Crypthelia seamount, Norfolk Ridge, 23º17’ S, 168º14’ E, 200–291 m,

Etymology. In honour of Dr Alain Crosnier, Muséum national d’Histoire naturelle, Paris, a pioneer of censusing marine life.

Diagnosis. Aulites with auriculate deltidial plates. Shell surface with radial lines. Hinge plates absent. Cardinal process in form of depression. Crura maniculiform, slightly divergent with non-digitate, small extremities.

Depth range. 200– 291 m.

Measurements. (in mm).

Description. Shell very small (maximum length 1.5 mm), thin, translucent, oval to subtriangular in outline, weakly biconvex with ventral valve slightly more convex. Shell surface smooth with numerous faint radial lines, these more distinct on ventral valve ( Fig. 5 F, H). Anterior commissure rectimarginate, lateral commissures straight. Hinge margin slightly curved. Beak erect with large, subtriangular hypothyrid foramen; deltidial plates thickened, erect, laterally auriculate. Ventral valve with narrow, sessile pedicle collar. Teeth small, hooked without dental plates. Dorsal valve interior with very high median septum triangular in profile. Cardinal process in form of depression. No hinge plates. Crura short, slender, slightly divergent with small, non-digitate extremities. Muscle scars distinct.

Remarks. The genus Aulites was created by Richardson (1987) for specimens very similar to Cryptopora but lacking dental plates. The type species A. brazieri (Crane, 1886) is known from the Miocene to Recent of southern Australia ( Richardson 1987; Logan 2007). Aulites crosnieri is only the second species in the genus, differing from A. brazieri in being much smaller, in having auriculate deltidial plates and in the absence of hinge plates.

Figures

FIGURE 5. Aulites crosnieri sp. nov., Norfolk Ridge, Norfolk 1 Stn DW 1724, 200 – 291 m: A, dorsal view of young specimen, paratype, MNHN BRA- 3137; B – E, paratype, MNHN BRA- 3138, B, C, dorsal view of complete specimen and enlargement of the umbonal part to show details of the beak, D, E, interior views to show crura and septum (D) and teeth without dental plates (E); F – J, complete specimen, holotype, MNHN BRA- 3136, F, G, ventral and dorsal views and tilted ventral view (H) to show details of radial ornamentation, I, J, enlargement of the umbonal part to show details of the beak (I) and fine capillation anterior to the protegular node (J). All SEM.