Fukami River bank and floor, Ajimu-machi, Usa City: Late Pliocene, Japan
collected 1990'

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Osteichthyes
Alligator sinensis Fauvel 1879
left quadrate (LBM 0142000027), left dentary (LBM 0142000753), left angular (LBM 0142000754), left articular (LBM 0142000756)
left jugal (LBM 0142000054), isolated teeth (LBM 0142000020; LBM 0142000023; LBM 0142000036; LBM 0142000039; LBM 0142000042; LBM 0142000044; LBM 0142000047; LBM 0142000049; LBM 0142000050), right ilium (LBM 0142000025), osteoderms (LBM 0142000030; LBM 0142000032; LBM 0142000035; LBM 0142000043; LBM 0142000046; LBM 0142000051)
see common names

Geography
Country:Japan State/province:Kyushu
Coordinates: 33.4° North, 131.3° East (view map)
Paleocoordinates:33.2° North, 130.7° East (Wright 2013)
Basis of coordinate:based on nearby landmark
Geographic resolution:small collection
Time
Period: Neogene Epoch: Pliocene
Stage: Piacenzian 10 m.y. bin: Cenozoic 6
Key time interval: Late Pliocene
Age range of interval: 3.6 - 2.58 m.y. ago
Stratigraphy
Formation:Tsubusagawa
Stratigraphic resolution:bed
Stratigraphy comments: Lowermost part of the middle Tsubusagawa Formation

Iijima et al. 2016: Although some age estimates and their stratigraphic levels are inconsistent, the age of the alligator fossil bearing horizon is most likely at ~3.0 Ma in the Late Pliocene.
Lithology and environment
Primary lithology:very fine sandstone
Includes fossils?Y
Lithology description: Iijima et al. 2016: All the crocodylian materials described here were recovered from very fine sandstone (Matsuoka, 2001) of the lowermost part of the middle Tsubusagawa Formation, which crops out at the Fukami River bank and floor, upstream of Shiromaru-bashi Bridge, Ajimu-machi, Usa City, Oita Prefecture (Fig. 2).
Environment:fluvial-lacustrine indet. Tectonic setting:intramontane basin
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:taxonomic analysis
Collection dates:Late 1990's
Metadata
Also known as:Upstream of Shiromaru-bashi Bridge; Ajimu fauna; Oita Prefecture
Database number:180691
Authorizer:P. Mannion Enterer:P. Mannion
Modifier:G. Varnham
Created:2016-07-28 05:57:52 Last modified:2025-02-22 15:12:02
Access level:the public Released:2016-07-28 05:57:52
Creative Commons license:CC0
Reference information

Primary reference:
59998. M. Iijima, K. Takahashi, and Y. Kobayashi. 2016. The oldest record of Alligator sinensis from the Late Pliocene of Western Japan, and its biogeographic implication. Journal of Asian Earth Sciences 124:94-101 [P. Mannion/P. Mannion]

Secondary references:

65770 M. Iijima, A. Momohara, Y. Kobayashi, S. Hayashi, T. Ikeda, H. Taruno, K. Watanabe, M. Tanimoto, and S. Furui. 2018. Toyotamaphimeia cf. machikanensis (Crocodylia, Tomistominae) from the Middle Pleistocene of Osaka, Japan, and crocodylian survivorship through the Pliocene-Pleistocene climatic oscillations. Palaeogeography, Palaeoclimatology, Palaeoecology 496:346-360 [P. Mannion/P. Mannion]