USGS Mesozoic loc. 8567 (Jurassic of the United States)

Where: Alaska (61.9° N, 148.2° W: paleocoordinates 29.2° N, 81.2° W)

• coordinate estimated from map

When: Tuxedni Formation, Bajocian (170.3 - 168.3 Ma)

• Middle Bajocian

Environment/lithology: marine; sandstone and sandy shale

• From Martin, 1926:

•"The Tuxedni sandstone of the Matanuska Valley is composed of sandstone and sandy shale. The thickness has not been accurately determined but is known to be at least several hundred feet and may be a thousand feet or more. The formation contains abundant marine fossils and was probably deposited wholly in marine waters, although some of the sandstone beds contain abundant poorly preserved vegetable remains, mostly water worn sticks and stems. The Tuxedni sandstone rests upon the Lower Jurassic volcanic rocks, described above, but the scarcity of well-marked bedding planes in those rocks makes it difficult to determine whether the contact is conformable or unconformable. The Tuxedni is overlain by the Chinitna formation, described below, with apparent conformity."

Size classes: macrofossils, mesofossils

Primary reference: T. P. Poulton. 1979. Jurassic Trigoniid Bivalves from Canada and Western United States of America. Geological Survey of Canada Bulletin 282 [G. Stanley/H. Shepherd/H. Shepherd]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 139479: authorized by George Stanley, entered by Hannah Shepherd on 12.02.2013

Creative Commons license: CC BY (attribution)

Taxonomic list

 Trigoniida - Myophorelloidae
Myophorella dawsoni Whiteaves 1878 clam