Foraminifera source details
Hanagata, S.; Matsue, D.; Matsubara, T. (2023). Foraminifera of the Eocene Shitakara Formation in eastern Hokkaido, with the designation of neotype specimens of Yoshida (1957). Micropaleontology. 69(3): 303-325.
450978
10.47894/mpal.69.3.02 [view]
Hanagata, S.; Matsue, D.; Matsubara, T.
2023
Foraminifera of the Eocene Shitakara Formation in eastern Hokkaido, with the designation of neotype specimens of Yoshida (1957)
Micropaleontology
69(3): 303-325
Publication
Forty-three species belonging to thirty-seven genera of benthic foraminifera were differentiated from the Eocene Shitakara Formation in the eastern part of the Kushiro Coalfield, eastern Hokkaido. The foraminiferal assemblages show upward transgression from the inner to outer sublittoral condition. They contain abundant agglutinated and calcareous hyaline benthic species, including Labrospira crassiformis, Haplophragmoides subamakusaensis, and Cribroelphidium sorachiense, indicating similarity to the Eocene fauna in central Hokkaido. Two planktonic species Chiloguembelina ototara and Tenuitella insolita also indicate a late Eocene age. Neotype specimens of Cyclammina pacifica var. kushiroensis, Nonion kushiroense, and Nonion sorachiense var. konbumoriense described by Yoshida (1957) have been designated as replacements for holotype specimens that were lost in a fire in May 1965. A taxonomical reexamination based on the neotypes and topotypes indicates that Cyclammina pacifica var. kushiroensis is a distinct species, whereas Nonion kushiroense and Nonion sorachiense var. konbumoriense are junior synonyms of Cribroelphidium sorachiense (Asano 1954). All foraminiferal taxa are illustrated with taxonomical notes.
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Cyclammina kushiroensis Yoshida, 1957 † (new combination reference)
Cyclammina pacifica var. kushiroensis Yoshida, 1957 † accepted as Cyclammina kushiroensis Yoshida, 1957 † (subsequent type designation)
Elphidiella smithi (Cushman & Dusenbury, 1934) † (new combination reference)
Globocassidulina diversa (Cushman & Stone, 1949) † accepted as Cassidulina diversa Cushman & Stone, 1949 † (new combination reference)
Haplophragmoides subamakusaensis Fukuta, 1962 † (additional source)
Haplophragmoides subevolutus Kaiho, 1984 † accepted as Haplophragmoides subamakusaensis Fukuta, 1962 † (source of synonymy)
Labrospira crassiformis (Kaiho, 1984) † (new combination reference)
Laevidentalina approximata (Reuss, 1866) † accepted as Dentalinoides approximata (Reuss, 1866) † (new combination reference)
Nonion kushiroense Yoshida, 1957 † accepted as Cribroelphidium sorachiense (Asano, 1954) † (source of synonymy)
Nonion kushiroense Yoshida, 1957 † accepted as Cribroelphidium sorachiense (Asano, 1954) † (subsequent type designation)
Nonion pompilioides subsp. shimokinense Asano, 1958 † accepted as Nonion pompilioides (Fichtel & Moll, 1798) accepted as Melonis pompilioides (Fichtel & Moll, 1798) (source of synonymy)
Nonion sorachiense var. konbumoriense Yoshida, 1957 † accepted as Cribroelphidium sorachiense (Asano, 1954) † (subsequent type designation)
Nonion sorachiense var. konbumoriense Yoshida, 1957 † accepted as Cribroelphidium sorachiense (Asano, 1954) † (source of synonymy)
Placentammina vulgaris (Bogdanovich, 1963) † (new combination reference)
Pseudonodosaria obtusissima (Reuss, 1863) † (new combination reference)
Cyclammina pacifica var. kushiroensis Yoshida, 1957 † accepted as Cyclammina kushiroensis Yoshida, 1957 † (subsequent type designation)
Elphidiella smithi (Cushman & Dusenbury, 1934) † (new combination reference)
Globocassidulina diversa (Cushman & Stone, 1949) † accepted as Cassidulina diversa Cushman & Stone, 1949 † (new combination reference)
Haplophragmoides subamakusaensis Fukuta, 1962 † (additional source)
Haplophragmoides subevolutus Kaiho, 1984 † accepted as Haplophragmoides subamakusaensis Fukuta, 1962 † (source of synonymy)
Labrospira crassiformis (Kaiho, 1984) † (new combination reference)
Laevidentalina approximata (Reuss, 1866) † accepted as Dentalinoides approximata (Reuss, 1866) † (new combination reference)
Nonion kushiroense Yoshida, 1957 † accepted as Cribroelphidium sorachiense (Asano, 1954) † (source of synonymy)
Nonion kushiroense Yoshida, 1957 † accepted as Cribroelphidium sorachiense (Asano, 1954) † (subsequent type designation)
Nonion pompilioides subsp. shimokinense Asano, 1958 † accepted as Nonion pompilioides (Fichtel & Moll, 1798) accepted as Melonis pompilioides (Fichtel & Moll, 1798) (source of synonymy)
Nonion sorachiense var. konbumoriense Yoshida, 1957 † accepted as Cribroelphidium sorachiense (Asano, 1954) † (subsequent type designation)
Nonion sorachiense var. konbumoriense Yoshida, 1957 † accepted as Cribroelphidium sorachiense (Asano, 1954) † (source of synonymy)
Placentammina vulgaris (Bogdanovich, 1963) † (new combination reference)
Pseudonodosaria obtusissima (Reuss, 1863) † (new combination reference)