Sososhisawa, Inasato (Locality 1): Early/Lower Maastrichtian, Japan
collected by K. Chiyokawa & T. Furuno 1994

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Reptilia - Testudines - Dermochelyidae
Mesodermochelys undulatus Hirayama and Chitoku 1996
3 specimens
HMG 1062, dentary; HMG 1063, 1st and 2nd sacral and caudal vertebrae, pelvic girdle and right femur; HMG 1064, left pubis, peripherals and xiphiplastra
see common names

Geography
Country:Japan State/province:Hokkaido County:Hobetsu
Coordinates: 42.9° North, 142.1° East (view map)
Paleocoordinates:46.9° North, 131.4° East
Basis of coordinate:estimated from map
Geographic resolution:small collection
Time
Period:Cretaceous Epoch:Late/Upper Cretaceous
Stage:Maastrichtian 10 m.y. bin:Cretaceous 8
Key time interval:Early/Lower Maastrichtian
Age range of interval:70.60000 - 66.00000 m.y. ago
Stratigraphy
Geological group:Yezo Formation:Hakobuchi Member:Lower sandy Siltstone
Stratigraphic resolution:bed
Stratigraphy comments: The middle portion of the lower sandy siltstone formation consists of dark gray sandy siltstone, bearing marine invertebrates such as Inoceramus (Cataceramus) shikotanensis, Pachydiscus (Neodesmoceras) japonicus and Neophylloceras hetonaiensis which indicate an early lower Maastrichtian age.
Lithology and environment
Primary lithology:concretionary,gray sandy,calcareous siltstone
Includes fossils?Y
Lithology description: All material described here was contained in sandy calcareous concretions which came from the surface outcrop of the lower sandy siltstone formation of the Hakobuchi Group as found in Central Hokkaido. It is characterised by coarse grained sediments consisting mainly of sandstones... The middle portion of the lower sandy siltstone formation consists of dark gray sandy siltstone, bearing marine invertebrates such as Inoceramus (Cataceramus) shikotanensis, Pachydiscus (Neodesmoceras) japonicus and Neophylloceras hetonaiensis which indicate an early lower Maastrichtian age.
Environment:marine indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection methods:surface (float),surface (in situ),mechanical,acetic,field collection
Reason for describing collection:taxonomic analysis
Collectors:K. Chiyokawa & T. Furuno Collection dates:November 2, 1994
Collection method comments: Collection of Hobetsu Museum at Hobetsu-cho, Hokkaido, Japan
Metadata
Database number:129278
Authorizer:R. Benson Enterer:R. Benson
Modifier:P. Mannion Research group:vertebrate
Created:2012-06-23 00:46:05 Last modified:2021-03-16 13:26:54
Access level:the public Released:2012-06-23 00:46:05
Creative Commons license:CC BY
Reference information

Primary reference:

42111. R. Hirayama and T. Chitoku. 1996. Family Dermochelyidae (superfamily Chelonioidea) from the Upper Cretaceous of north Japan. Transactions and Proceedings of the Palaeontological Society of Japan. New series 184:597-622 [R. Benson/R. Benson]