Ravine 35 (trigona zone, 4100 ft), southwest slope of Mount Jura (Jurassic of the United States)

Where: California (40.1° N, 120.8° W: paleocoordinates 33.2° N, 60.1° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Sonninia alsatica ammonoid zone, Mormon Sandstone Member (Mormon Formation), Discites (171.6 - 167.7 Ma)

• The trigona zone is associated with S. alsatica which is correlated with the upper Discites zone according to Riding 2010 ("New evidence for the age of the Athol Formation (Middle Jurassic; Bajocian) in the Tusk-1 and Tusk-2 wells, offshore Carnarvon Basin, Western Australia")

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified, fine-grained, volcaniclastic, gray, green, red, muddy, conglomeratic sandstone

• Mainly fine gray arkose, with red and green conglomerate of volcanic debris at the base, and fine, dark gray paper shales at top

Size class: macrofossils

Reposited in the GSC

Primary reference: C. H. Crickmay. 1933. Attempt to Zone the North American Jurassic on the Basis of its Brachiopods. Geological Society America Bulletin 44:871-894 [M. Clapham/M. Manojlovic]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 164683: authorized by Matthew Clapham, entered by Marko Manojlovic on 10.12.2014

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Rhynchonellata
 Terebratulida - Zeilleriidae
Ornithella syringothyrides n. sp.
Ornithella syringothyrides n. sp. Crickmay 1933