Nishikosa: Early Albian - Middle Albian, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Osteichthyes - Troodontidae
1 specimen
Holotype MNHAH D1033340
see common names

Geography
Country:Japan State/province:Hyōgo
Coordinates: 35.1° North, 135.2° East (view map)
Paleocoordinates:39.5° North, 146.1° East (Wright 2013)
Basis of coordinate:stated in text
Time
Period: Cretaceous Epoch: Early Cretaceous
Stage: Albian 10 m.y. bin: Cretaceous 4
Key time interval: Early Albian - Middle Albian
Age range of interval: 113.2 - 106.3 m.y. ago
Age estimate: 112.1 ± 0.4 to 106.4 ± 0.4 Ma (U/Pb)
Stratigraphy
Geological group:Sasayama Formation:Ohyamashimo
Stratigraphy comments: Kubota et al. (2024): U–Pb ages of zircons indicate 112.1 ± 0.4 Ma for the lowermost part of the Ohyamashimo Formation and 106.4 ± 0.4 Ma for the lower part of the overlying Sawada Formation^26. Thus, the middle part of the Ohyamashimo Formation is assigned to be the early to middle Albian in age."
Lithology and environment
Primary lithology: muddy sandstone
Includes fossils?Y
Environment:fluvial indet.
Geology comments: Kubota et al. (2024): "The partial skeleton of Hypnovenator was buried in muddy sandstone of fluvial deposits under low-energy water flow, containing plant fragments."
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:general faunal/floral analysis
Taxonomic list comments:According to Kubota et al. (2024), plant fragments were contained in the the sandstone, where the Hypnovenator type specimen was uncovered, but no further details a re given on them (Hence, they won't be included in the taxonomic list for now).
Metadata
Database number:235979
Authorizer:E. Dunne Enterer:E. Tasimov
Modifier:E. Tasimov Research group:vertebrate
Created:2024-08-31 11:31:00 Last modified:2025-02-22 15:12:02
Access level:the public Released:2024-08-31 11:31:00
Creative Commons license:CC0
Reference information

Primary reference:

89323. K. Kubota, Y. Kobayashi, and T. Ikeda. 2024. Early Cretaceous troodontine troodontid (Dinosauria: Theropoda) from the Ohyamashimo Formation of Japan reveals the early evolution of Troodontinae. Scientific Reports 14(16392):1-14 [E. Dunne/E. Tasimov]