Obira, on the Obirashibe River (Cretaceous to of Japan)

Where: Hokkaido, Japan (44.1° N, 142.0° E: paleocoordinates 52.6° N, 134.9° E)

• coordinate stated in text

• small collection-level geographic resolution

When: Biostrina nipponica ammonoid zone, Middle Yezo Group, Late/Upper Cenomanian to Late/Upper Cenomanian (99.6 - 89.3 Ma)

Environment/lithology: offshore; lithified, massive siltstone

• "This locality is relatively poor in megafossils compared with other parts of the Middle Yezo Group. The outcrops are mainly composed of monotonous siltstone, suggesting a constant supply of fine sediments in a low energy, offshore environment. The strata at the locality dip about 50 degrees west, and are almost perpendicular to the outcrop surface, suggesting that missing parts of the fossil had been eroded away before excavation.

Size class: macrofossils

Primary reference: T. Sato and G. W. Storrs. 2000. An early polycotylid plesiosaur (Reptilia: Sauropterygia) from the Cretaceous of Hokkaido, Japan. Journal of Paleontology 74(5):907-914 [M. Carrano/H. Street]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 102078: authorized by Matthew Carrano, entered by Hallie Street on 07.01.2011

Creative Commons license: CC BY (attribution)

Taxonomic list

Reptilia
 Sauropterygia - Polycotylidae
Polycotylidae indet. Williston 1908 plesiosaur
UMUT MV 19965 (2 cervicals, 1 dorsal, 2 sacrals, 4 caudals, 3 indet. vertebrae partial pectoral girdle, ribs, right forelimb, fragmentary pectoral girdle, stomach contents)