Kotora HATAI

ハタイ コトラ

National Institute of Polar Research Repository

1 Through the kindness of Dr. ToKIOKA of the Seto Marine Biological Labora­tory of the Kyoto University at Shirahama, Wakayama Prefecture, an interesting brachiopod obtained by Dr. R. Yosn during the Second Japanese Antarctic Research Expedition was forwarded to the writer for study. An examination of the brachiopod, which consisted of several well preserved specimens, revealed that it belongs to the genus Crania, and may be an undescribed species. Phylum Brachiopoda Family Craniidae KING, 1846 Genus Crania RETZIUS, 1781 The brachiopod genus Crania is based upon Crania brattensburgensis RETzms= Anomia craniolaris LINNE, a fossil species. According to THOMSON (1927, p. 136), the genus ranges from the Eocene of Belgium and Italy, through the Miocene of France, Italy and New Zealand, the Pliocene of Sicily and Italy, to the Recent seas of the Atlantic, Pacific and Indian Oceans including the Mediterranean, and is also known from the Antarctic region. A genus similar to the present one, Ancistrocrania, based upon Crania parisiensis DEFRANCE is found in the Cretaceous sediments and is also reported to inhabit the seas of Japan (ALLAN, 1937). It may be added that HALL and CLARK (1892, according to THOMSON, 1927, p. 136) give the range of the genus Crania from early Silurian to Recent. All specimens at hand are only the dorsal valves which are in natural col­oration, well preserved, sometimes retaining the animal, and show a rather wide range of variation of the shell. The very thin shell and other details to be men­tioned later seem to indicate that the specimens belong to the genus Crania, and more or less close to Crania lecointei JouBIN (JoUBIN, 1901, p. 9, pl. 2, figs. 13-15), a Recent species which was obtained by the S.Y. Belgica during her expedition to the Antarctic region, from a depth of 273 fathoms. The greatest depth recorded of the genus is that by DALL (1920, p. 273), who lists Crania patagonica DALL from a depth of 348 fathoms in the Magellan Straits. Although the writer has not been able to see Crania joubini THOMSON, which was reported by THOMSON (1927, p. 134) from the depth of 240 fathoms in the Davis Sea, Antarctica and which seems to closely resemble the present specimens at least from the brief remarks by THOMSON (op. cit.). It should be mentioned that THOMSON referred his joubini to the genus Discina LAMARCK, 1819 with some doubt. THOMSON'S species is represented only by the dorsal valves, just as in 2 On a species of Crania (Branchiopo<la) from Antarctica the case of the present specimens. But since the present specimens seem better placed in the genus Crania, it may be thought that both Discina and Crania contain species bearing superficial resemblance. The genotype of Disciua is Discina ostreoides LAMARCK=Crania striata SCHUMACHER, originally reported l'rnrn Cape Palmas, West Africa, according to DALL (1920, p. 275). Crania antarcticaensis HATAI, n. sp. Figs. 1 a-5 b. Description: Dorsal valve subquandrangular in shape, narrower posteriorly than anteriorly, posterior and anterior margins either somewhat straight or slightly rounded, generally more rounded in the anterior margin. Beak subcentral, situated posteriorly, near the rather short and straight posterior margin of the shell. Apex bluntly pointed, elevated. External surface with concentric growth lines and minute pustulose sculpture, the latter may be almost absent making the surface rather smooth. Concentric growth lines may be rough to more or somewhat smooth and appear as mere impressed lines. Interior with two seperated, rounded and elevated muscular scars situated near the posterior margin, elongate ovate or ovate in general shape. Anterior adductor scars situated a little posterior to middle of valve, separated from one another but closer than posterior adductors, slightly elevated and of irregular shape. No grooves for reception of pallial sinuses seen distinctly. Inner surface of ventral valve white in color and show minute punctations. External surface light brownish white in color and sometimes light brownish yellow. Minute punctations observable from external surface. Brachia spirolophus. Dimensions (in mm) : Length Cantero-posterior) .............................. 10.0 8.0 Width ......................................................... 12.0 9.5 Height of shell ............................................. 4.0 3.0 9.6 12.0 3.5 8.6 10.0 3.5 9.1 8.2 2.6 Localities: Inner part of Lutzow-Holm Bay, 570 m depth, February 8, 1958. Off Cape Cook, 500 m depth, January 28, 1958. Off Cape Cook, 700 m depth, sandy bottom, February 1, 1958. Gunnerus Bank, 590 m depth, Februry 1, 195B. Remarks: Some of the present specimens more or less resemble Crania le­cointei JouBIN (1901, p. 9, pl. 2, figs. 13-15) from a depth of 500 meters at "Faubert VIL-Lat. 70 °23'S, Long. 82 ° 47'W ", but differs from the latter in the position of the apex, general shape of the shell, different growth lines and external sculpture. In the present species the beak is su bcentral in position unlike lecointei, and the posterior margin is shorter than that of the latter ; the concentric growth lines are stronger and apparently elevated in lecointei but not so in the present one. So far as the general outline is concerned, Vladiviathyris quenstedti HELMCKE (ROWELL, 19Gl, pl. 68, figs. 5-7) resembles some of the present specimens, and Ancistrocrania parisiensis (DEFRANCE) (ROWELL, 19bl, pl. b8, figs. 3, 4) is another species similar to the present in shape. However, the latter differs Crom the present specimens in the peculiar internal structures or the ... ventral valve and in the position of the apex. The former also differs from the present specimens by having the peculiar internal structures of the shell. Crania antarcticaensis HATAI, n. sp. 3 Crania valdiviae HELMCKE (1940, p. 234, text-fig. 4) resembles the present speci­mens in the rather short posterior margin and subcentral position of the beak, but differs in the general outline of the shell and in the details of the external surface sculpture and adductor scars. Species similar to the present specimens are not illustrated by HERTLEIN and GRANT (1944) who made a monographic study of the Cenozoic brachiopods of western North America. No species identical with the present one are noted in the work of FISCHER and OEHLERT (1891) who described and illustrated the material of "Du Travaillcur et de Talisman". DAVIDSON (1888) in his monograph of Recent brachiopods has described and illustrated many species of the group under consideration, but none seems to be identical with the present specimens. Crania chathamensis ALLAN (1937, p. 155, pl. lG, fig. 4) from the Tertiary rocks of the Chatham Islands, New Zealand can be easily distinguished from the present specimens by the position of the apex, general shape of the shell and surface ornamentation. However, concerning Crania joubini THOMSON, which THOMSON (1927, p. 134) referred to the genus Discina with the remarks that, " known from the dorsal valve only, is without radial ornamentation, and is finely punctate internally, but is without strongly marked muscular impression typical of Crania, and may possibly be more allied to Discina ", it is difficult to be compared with the present specimens because no illustration or description of the species is available to the writer. The present specimens have no radial ornament, and the dorsal valve is finely punctate internally and without very strong muscular scars; in these respects, apparent similarity to THOMSON'S species just mentioned is suggested. Whether the present specimens are identical with Crania jouhini THOMSON is difficult to determine at present, although it may be suggesu·d t hnt the generic posit ion of his species is not I he same as 1 hat of 1 he presPnt specinH�ns. References ALLAN, R. S., 1937: Type Brachiopoda in the Canterbury Museum. Rec. Cant. Mus., 4, No. 3, 114-128, pis. 15-16. ALLAN, R.S., 1937: A New Tertiary Crania (Brachiopoda) from the Chatham Islands, New Zealand. Ibid., 4, No. 3, 155-156, pl. 16, fig. 4. ALLAN, R.S., 1940: Studies on the Recent and Tertiary Brachiopoda of Australia and New Zealand, Part 2. Ibid., 4, No. 6, 277-297, pis. 35-37. DALL, W. H., 1920: Annotated List of the Recent Brachiopoda in the Collection of the United States National Museum, with Description of Thirty-three New Forms. Proc. U. S. Nat. Mus., 57, No. 2314, 261-377. DAVIDSON, T., 1888: A Monograph of the Recent Brachiopoda. Trans. Linnean Soc. London, Sec. Ser. Zoology, 4, Pt. 3, 183-248, pis. 26-30. F1scHER, P., and OEHLERT, D. P., 1891: Expeditions Scientifiques du Travailleur et du Talisman pendant les annees 1880, 1881, 1882, 1883, 139 pp., 8 pis. HELMCKE, J.G., 1940: Die Brachiopoden der Deutschen Tiefsee-Expedition. Wissenschaftliche Ergebnisse der Deutschen Tiefsee-Expedition auf dem Dampfer "Valdivia'' 1898-1899, pp. 217-316. 4 HELMCKE, J. G., 1940: Validiviathyridae, eine neue Brachiopoden-Familie. Zool. Anzeiger, 130, Heft 5/6, 135-139, 1 fig. HERTLEIN, L. G., and GRANT, U.S., 1944: The Cenozoic Brachiopoda of Western North America. Pub!. Univ. Calif., Math. Phys. Sci., 3, 1-236, 21 pls. JouBIN, L., 1901: Resultats du Voyage du S. Y. Belgica en 1897-1898-1899, pp. 3-11, 2 pls. OoHNER, N. H., 1948: Reports of the Swedish Deep-Sea Expedition 1947-1948, Goteborgs Kung!. Vetenskaps-och Vitterhets-Samhalle, 2, Zoology, Fasc. IV, 403-406, 1 fig. ROWELL, A . .J., 1961: The Brachiopod Genus Valdiviathyris Helmcke. Paleont., 4, Pt. 4, 542-545, pl. 68. THOMSON, J. A., 1927: Brachiopod Morphology and Genera (Recent and Tertiary). New Zeland Bd. Sci. Arts, Man. No. 7, 338 pp., 2 pls. (Manuscript receivea March 22, 1965) 

On the Species of Crania (Branchiopoda) from Antarctica

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On the Species of Crania (Branchiopoda) from Antarctica

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