UCLA loc. 3470, North Fork of Cottonwood Creek (Cretaceous of the United States)

Also known as LACMIP loc. 23470

Where: Shasta County, California (40.5° N, 122.6° W: paleocoordinates 41.6° N, 82.7° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Bald Hills Member (Budden Canyon Formation), Early/Lower Cenomanian (99.6 - 93.5 Ma)

• "The Bald Hills Fm. ranges in age from upper Albian through Cenomanian and possibly into the lower Turonian." JA: the Bald Hills is actually a member of the Budden Canyon Formation and Lower Cenomanian according to Murphy and Rodda 1996

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified sandstone

• (The samples from this locality come from a congl. ~1200' higher above basal congl., according to the strat column). Congl. grain size from fine sand to boulders, avg. 2" diam. Well rounded; matrix med- to coarse-grained graywacke or very sandy mudstone. Majority of cobbles are dark porphyritic volcanics, remainder include metamorphic and granitic rocks, chert, mudstone and limestone. Congl. are sometimes fairly well bedded, esp. near tops, where they almost always grade upward to massive, then finely bedded sandstones.

Size class: macrofossils

Collection methods: mechanical,

Primary reference: M. A. Murphy and P. U. Rodda. 1960. Mollusca of the Cretaceous Bald Hills Formation of California. Journal of Paleontology 34(5):835-858 [J. Alroy/M. Sommers/J. Alroy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 1808: authorized by John Alroy, entered by Mike Sommers on 08.06.1999, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

• Abundances: R= rare (1-2), U= uncommon (3-10), A= abundant (>10). Authors very unclear as to whether specimens are found in matrix of the conglomerate or within clasts. "Some of the species found in the nodules and other reworked sedimentary rocks were extant at the time this conglomerate unit was deposited." They also list Cucullaea truncata (Gabb) as "...occurs below, above and in the matrix of the conglomerate as well as in the clasts of the conglomerate," then they do not list it in the species list.
Show authors, comments, and common names
Gastropoda
 Heterostropha - Acteonidae
Tornatellaea aff. impressa
Tornatellaea aff. impressa Gabb 1864 snail
originally entered as "Tornatellaea aff. impressa"
 Trochoidea - Turbinidae
"Solariella stewarti" = Igonoia stewarti
"Solariella stewarti" = Igonoia stewarti Murphy and Rodda 1960 snail
sp. nov.
 Cerithioidea - Turritellidae
Turritella xylina
Turritella xylina Squires and Saul 2006 turret shell
originally entered as "Turritella cf. robertiana"
 Sorbeoconcha - Naticidae
Euspira popenoei
Euspira popenoei Murphy and Rodda 1960 moon snail
sp. nov.
 Sorbeoconcha - Aporrhaidae
Tessarolax trinalis
Tessarolax trinalis Murphy and Rodda 1960 snail
sp. nov.
 Neogastropoda - Buccinidae
Cantharus occidentalis
Cantharus occidentalis Gabb 1869 true whelk
 Neogastropoda - Fasciolariidae
Paleopsephaea sacramentica
Paleopsephaea sacramentica Murphy and Rodda 1960 snail