Cretaceous cold-seep deposits of the Yezo Group on Hokkaido, Japan, yield a rich and well-preserved mollusk fauna. The systematics of nine bivalve species previously reported from these deposits can now be reevaluated using newly collected fossils. The fossils include a Cenomanian specimen of Nucinella gigantea with a drill hole possibly made by a naticid, by far the oldest record of a drill hole from a cold seep site. In Japan, Cretaceous seep bivalve assemblages are characterized by (i) the unique occurrence of large specimens of Nucinella (Manzanellidae), (ii) the commonly present nuculid Acila (Truncacila), and (iii) a high diversity of lucinids, possibly as many as four distinct genera. Two new species described are the Albian Acharax mikasaensis (Solemyidae) and the Albian to Campanian Thyasira tanabei (Thyasiridae), of which the former had previously been misidentified as the oldest vesicomyid, the latter as the oldest Conchocele.
How to translate text using browser tools
1 September 2008
Bivalves from Cretaceous Cold-Seep Deposits on Hokkaido, Japan
Steffen Kiel,
Kazutaka Amano,
Robert G. Jenkins
Acta Palaeontologica Polonica
Vol. 53 • No. 3
September 2008
Vol. 53 • No. 3
September 2008
chemosymbiosis
Cretaceous
hydrocarbon seeps
Japan
Lucinidae
Manzanellidae
Solemyidae