Campages ovalis, Bitner, 2008

Bitner, Maria Aleksandra, 2008, New data on the recent brachiopods from the Fiji and Wallis and Futuna islands, South-West Pacific, Zoosystema 30 (2), pp. 419-461 : 449

Campages ovalis n. sp.

( Fig. 18 )

TYPE MATERIAL. — Fiji. Lau Ridge , BORDAU 1, stn DW 1469, holotype, ( MNHN BRA-3116 ; Fig. 18A, B ). — Same data, 3 paratypes ( MNHN BRA-3117-3119 ; Fig. 18 C-J) .

TYPE LOCALITY. — Fiji, Lau Ridge, BORDAU 1, stn DW 1469, 19°40.01’S, 178°10.24’W, 314- 377 m.

ETYMOLOGY. — From the Latin oval, referring to the oval outline of the shell.

DIAGNOSIS. — Campages of small size, elongate oval in outline, strongly biconvex, rectimarginate, descending branches slender, hood very broad.

MATERIAL EXAMINED. — Wallis and Futuna. MUS- ORSTOM 7, Futuna, stn DW 513, 1 complete specimen.

Fiji. BORDAU 1, Lau Ridge, stn DW 1410, 1 young complete specimen. — Stn DW 1440, 1 complete specimen. — Stn DW 1469, 19 complete specimens, 2 ventral valves, 1 dorsal valve. — Stn DW 1485, 2 complete specimens.

DEPTH RANGE. — 190- 410 m.

MEASUREMENTS. — See Table 18.

DESCRIPTION

Shell small, oval in outline, densely punctate, subtransparent and strongly biconvex. Shell surface smooth with indistinct growth lines. Lateral commissures straight; anterior commisure rectimarginate. Beak suberect; no beak ridges are developed. Foramen small, circular, mesothyrid to permesothyrid. Deltidial plates conjunct forming a symphytium. Pedicle collar short. Teeth small without dental plates ( Fig. 18F, G ). Cardinal process large, transverse, kidney-shaped.Inner socket ridges long. Outer hinge plates well-developed; inner hinge plates fused to the median septum forming septalium ( Fig. 18J ). Crural bases weakly differentiated. Median septum, constituting half of the valve length, is high posteriorly, sloping rapidly to become very low anteriorly. Crura long, slender with short, sharply pointed crural processes. Loop diploform; descending branches narrow, parallel; hood extremely broad ( Fig. 18H, I ). Muscle scars strongly defined on both valves.

REMARKS

The specimens show internally all the characters typical of Campages . The genus Jaffaia Thomson, 1927 which has a very similar loop is distinguishable from Campages by the presence of beak ridges and absence of pedicle collar. The Fiji material differs from other Campages species in having a relatively small foramen and elongate-oval outline, while typical Campages is subtriangular. In the revised edition of the Treatise, Logan (2007) listed seven species of Campages , six of which are known from off Japan ( Dall 1920; Hatai 1940). Cooper (1970), in his revision of the genera Campages and Japanithyris Thomson, 1927 , suggested that C. basilanica Dall, 1920 , C. mariae (Adams, 1860) and C. pacifica Hatai, 1940 might be synonymous. All those species, as well as C. furcifera Hedley, 1905 are much larger than the investigated specimens and their anterior commissure has broad to strong folding ( Cooper 1970). Campages philippinensis Cooper, 1970 is of similar size but differs from the studied material in having distinct growth lines and the ventral valve several times deeper than the dorsal one ( Cooper 1970); the shell of C. ovalis n. sp. is nearly equally biconvex. Campages nipponensis ( Yabe & Hatai, 1935) is similar in size to the investigated material but differs in having prominent growth lines ( Yabe & Hatai 1935; Hatai 1940). In size, the specimens from Fiji are also close to C. dubius ( Hatai, 1940) from off Japan, differing in having much smaller foramen and less elongate outline.

Figures

FIG. 18. — Campages ovalis n. sp., Fiji, Lau Ridge, BORDAU 1, stn DW 1469, 314-377 m: A, B, dorsal and lateral views of complete specimen, holotype (MNHN BRA-3116); C-E, dorsal and lateral views of complete specimen, and enlargement (E) of posterior part, paratype (MNHN BRA-3117); F, G, inner view of ventral valve and enlargement (G) of posterior part, titled to show teeth without dental plates, paratype (MNHN BRA-3118); H-J, dorsal and side views of interior of dorsal valve to show brachial loop, and enlargement (J) of cardinalia, paratype (MNHN BRA-3119). All SEM. Scale bars: A-D, F, 2 mm; E, G-I, 1 mm; J, 500 μm.