Kanagasako, Tsubuta, Sanyoonoda-shi (Triassic of Japan)

Where: Japan (34.0° N, 131.1° E: paleocoordinates 43.0° N, 114.0° E)

• coordinate stated in text

• outcrop-level geographic resolution

When: Nakatsuka Formation, Julian (235.0 - 232.0 Ma)

• Ammonoids including Trachyceras cf. desatoyense (Johnston) (Ishibashi et al. 1990), Protrachyceras cf. archelaus (Laube) and Paratrachyceras cf. aonoides (von Mojsisovics) (Ishibashi et al. 2007), all document an early Carnian age

• group of beds-level stratigraphic resolution

Environment/lithology: coastal; lithified shale

• Interpreted as a shallow, nearshore marine deposit (Tokuyama 1962). It overlies

•the limnic to deltaic deposits of the Kajiura Formation.

• The grain size spectrum of the shale layers varies from pure clay to silty clay with numerous detrital mica flakes

Size class: macrofossils

Preservation: mold/impression

Reposited in the NHMW

• Repository: Mine City Museum of History and Folklore, Yamaguchi Prefecture, Japan (MMHF); The National Museum of Nature and Science, Tokyo, Japan (NMNS); Geowissenschaftliches Museum der Universität Göttingen, Göttingen, Germany (GZG.INV); and Naturhistorisches Museum Wien, Vienna, Austria (NHMW)

Primary reference: B. Thuy, Y. Ishida, E. Doi and A. Kroh. 2013. New ophiacanthid brittle stars (Echinodermata: Ophiuroidea) from the Upper Triassic of Japan: first insights into the origin and evolution of an extant deep-sea group. Journal of Systematic Palaeontology 11:515-530 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 152134: authorized by Matthew Clapham, entered by Matthew Clapham on 08.11.2013

Creative Commons license: CC BY (attribution)

Taxonomic list

Ophiuroidea
 Ophiacanthida - Ophiacanthidae
Leadagmara gracilispina n. gen. n. sp.
Leadagmara gracilispina n. gen. n. sp. Thuy et al. 2013 brittle star
and hundreds of dissociated ossiles