Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Evening Poster

B (Biogeosciences) » B-PT Paleontology

[B-PT06] Biotic History

Sun. May 20, 2018 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Isao Motoyama(Department of Earth and Environmental Sciences, Yamagata University), Takao Ubukata(Division of Geology & Mineralogy, Department of Earth & Planetary Sciences, Kyoto University), Kazuyoshi Moriya(早稲田大学 教育・総合科学学術院 地球科学専修)

[BPT06-P04] Fossil fish from the Lower Miocene Kamenoo Formation, the Yunagaya Group, in Northern Ibaraki prefecture

*Chihiro Hirata1, Miyata Shinya2, Hirochika Ueda3, Yoshiki Kouda4 (1.Tokyo City University, 2.Josai University, 3.Tokyo University, 4.Ibaraki Nature Museum)

Keywords:Early Miocene, Kamenoo Formation, Fossil Fish

Fossils from the Kamenoo Formation, the Yunagaya group in Early Miocene in Joban region is yielded molluscan, plant, micro fossil (e.g. diatom), and fossil fish. But, there are a few descriptions about fossil fish in this region. To study fossil fish from Kamenoo Formation is important to know the marine fish fauna of the Miocene of the Northwestern Pacific area.

Fossil fish from the Kamenoo Formation are fossil fish scales (about 90) and 2 skeletons, which had been trying to identify.

Caudal fin and scales of this skeleton is well preserved. The skeleton belongs to the genus of Neoscopelidae because of the following characters: the scales is Myctophiformes like cycloid; there is a gap between second and third hypurals (HY); the width of third and forth hypurals are wide; and preural centrum1 and ural centrum1 fused (PU1+ U1); and the first hypural is articulated with PU1+U1. Neoscopelus sp. and Glossanodon sp. have these characteristics. But Glossanodon sp. have no scales cycloid. So it is considered Neoscopelidae.(Myctophiformes)

The Neoscopelidae is first record in the Miocene of the Kamenoo Formation. Recent taxa of Mycyophiformes is classed by head and photogenic organ. Consequently, it is necessary for osteology and comparison of recent taxa of the genus Neoscopelus sp. to study taxonomy.