New Holocene calcified tubular foraminifera in acervulinid macroids from the Kikai Jima shelf, Ryukyu Islands, southwestern Japan
4 affiliations
- 1Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara
- 2Departamento de Estratigrafia y Paleontologia, Universidad de Granada
- 3Dipartimento di Fisica e Geologia, Università degli Studi di Perugia, Palazzina di Scienze, Piazza Università
- 4Department of Earth Science, Graduate School of Science, Tohoku University
Abstract
Two new genera and species of tubular foraminifera (Shimenawa okuyamae gen. et sp. nov. and Yorishiro morii gen. et sp. nov.) are described from approximately 4000-year-old nuclei of deep-water acervulinid macroids collected from the shelf off Kikai Jima, Ryukyu Islands (Japan). Macroids form extensive beds on mobile sandy and gravelly bioclastic carbonate sediments at water depths of 75–97 m. SEM and Raman analyses show that Shimenawa okuyamae is characterized by a porcelaneous texture with randomly oriented, needle-shaped calcite crystals, whereas Yorishiro morii possesses a three-layered shell composed of rhombohedral, plate-shaped, and rod-shaped calcite crystals. These shell textures have not previously been recognized or described in detail in foraminifera. Shimenawa okuyamae is tentatively assigned to the Squamulinacea based on its porcelaneous, imperforate, unilocular shell. Due to its novel shell texture among tubular foraminifera, Yorishiro morii cannot be assigned with certainty to any family or higher taxonomic rank.
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BibTeX
@article{bassi2026holocene,
title = {{New Holocene calcified tubular foraminifera in acervulinid macroids from the Kikai Jima shelf, Ryukyu Islands, southwestern Japan}},
author = {Davide Bassi and Juan Carlos Braga and Roberto Rettori and Komei Yamagishi and Hideko Takayanagi and Ryuji Asami and Yasufumi Iryu},
journal = {Progress in Earth and Planetary Science},
year = {2026},
month = oct,
doi = {10.1186/s40645-026-00852-5},
url = {https://doi.org/10.1186/s40645-026-00852-5},
note = {CC BY},
}
RIS
TY - JOUR
TI - New Holocene calcified tubular foraminifera in acervulinid macroids from the Kikai Jima shelf, Ryukyu Islands, southwestern Japan
AU - Davide Bassi
AU - Juan Carlos Braga
AU - Roberto Rettori
AU - Komei Yamagishi
AU - Hideko Takayanagi
AU - Ryuji Asami
AU - Yasufumi Iryu
PY - 2026
DA - 2026/10/25
JO - Progress in Earth and Planetary Science
DO - 10.1186/s40645-026-00852-5
UR - https://doi.org/10.1186/s40645-026-00852-5
AB - Two new genera and species of tubular foraminifera (Shimenawa okuyamae gen. et sp. nov. and Yorishiro morii gen. et sp. nov.) are described from approximately 4000-year-old nuclei of deep-water acervulinid macroids collected from the shelf off Kikai Jima, Ryukyu Islands (Japan). Macroids form extensive beds on mobile sandy and gravelly bioclastic carbonate sediments at water depths of 75–97 m. SEM and Raman analyses show that Shimenawa okuyamae is characterized by a porcelaneous texture with randomly oriented, needle-shaped calcite crystals, whereas Yorishiro morii possesses a three-layered shell composed of rhombohedral, plate-shaped, and rod-shaped calcite crystals. These shell textures have not previously been recognized or described in detail in foraminifera. Shimenawa okuyamae is tentatively assigned to the Squamulinacea based on its porcelaneous, imperforate, unilocular shell. Due to its novel shell texture among tubular foraminifera, Yorishiro morii cannot be assigned with certainty to any family or higher taxonomic rank.
SN - 2197-4284
ER -