Ti5, Tateishi-sawa: Capitanian, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Artiopoda - Proetida - Phillipsiidae
see common names

Geography
Country:Japan State/province:Miyagi
Coordinates: 39.0° North, 141.5° East (view map)
Paleocoordinates:3.2° North, 135.5° East (Wright 2013)
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
Period: Permian Epoch: Guadalupian
Stage: Capitanian 10 m.y. bin: Permian 4
Key time interval: Capitanian
Age range of interval: 264.28 - 259.857 m.y. ago
Stratigraphy
Formation:Kamiyasse Member:lower
Local section:Ti5 Local bed:280 m
Local order:bottom to top
Stratigraphic resolution:bed
Stratigraphy comments: Unit 3 of regional section, with units 1 & 2 in the underlying Hoso-o formation, unit 4 the upper part of Kamiyasse, and unit 5 to overlying Kurosawa formation.
Lithology and environment
Primary lithology:bioturbation sandy mudstone
Lithology description: sandy, fossiliferous mudstone
Environment:deep subtidal indet.
Geology comments: Unlike sandstone, the fossiliferous mudstone of unit-3 lacks a sedimentary structure indicative of high-energy events, e.g., storms or turbidity flows. Fenestrate bryozoans occasionally occur in life position in mudstone suggesting low-energy benthic conditions (Shiino et al., Reference Shiino, Suzuki and Kobayashi2011). However, the lenticular distribution of thin fossiliferous layers likely resulted from weak current activity that was able to sort small skeletal remains, e.g., crinoid columns and fragmented brachiopods and bryozoans. The dominance of isolated pygidia raises the possibility that sclerites were sorted by weak current activity (Adrain and Westrop, Reference Adrain and Westrop2016). In addition, the mudstone shows intense bioturbation that was enough to homogenize the original fossiliferous layers (Fig. 10.1). CT imaging revealed that the disarticulated parts are arranged in the same sequence as they were formed during enrollment, suggesting that the disarticulated remains originally represented complete enrolled trilobites (Fig. 10.3). It is likely that the set of disarticulated parts was originally enrolled individuals caught in a possible storm flow with sandy supply, eventually altered by the producers of Rhizocorallium isp. indet. Consequently, trilobites in the mudstone of unit-3 have suffered intense biological disturbances and weak fluid effects to become disarticulated specimens, as is also seen in obrution assemblages (e.g., Brett, Reference Brett1995; Brett et al., Reference Brett, Baird, Speyer, Brett and Baird1997).
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils,mesofossils
Collection methods and comments
Reason for describing collection:taxonomic analysis
Metadata
Database number:278689
Authorizer:P. Wagner Enterer:P. Wagner
Modifier:P. Wagner Research group:marine invertebrate
Created:2026-05-05 20:10:21 Last modified:2026-05-05 15:49:16
Access level:the public Released:2026-05-05 20:10:21
Creative Commons license:CC0
Reference information

Primary reference:
94747. N. Kudo and Y. Shiino. 2026. Taphonomy and environmental distribution of Pseudophillipsia in the middle Permian Kamiyasse Formation of the Southern Kitakami Terrane, Japan. Journal of Paleontology 1-18 [P. Wagner/P. Wagner]