UCMP V4041, Puerto Canyon (Jurassic to of the United States)

Where: Stanislaus County, California (37.5° N, 121.2° W: paleocoordinates 33.5° N, 67.4° W)

• coordinate based on nearby landmark

• hand sample-level geographic resolution

When: Pliensbachian to Pliensbachian (190.8 - 93.9 Ma)

• reworked chert cobble found in Quaternary stream gravels. Age range of Franciscan cherts in the Marin Headlands spans the Pliensbachian through Cenomanian.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, red chert

• "Dr. N. L. Taliaferro, who reports that the rock is: a red radiolarian chert identical with those so common in the Franciscan. This particular chert is identical with the cherts in the Franciscan [within five or six miles of the locality of occurrence]... many thin sections of which I have examined. The Radiolaria and the chert itself are completely recrystallized to a fine granular mosaic of quartz.... Minute granules and needles of zoisite and epidote are fairly abundant, . . . probably representing the recrystallization of small amounts of impurities originally present. The recrystallization shown by this chert could have been caused by deep burial under a thick prism of sediments such as actually accumulated in that particular region, or from heat developed from a nearby intrusive such as the ordinary serpentine or basalts of the Franciscan."

Size class: macrofossils

Collected by John Hammond in 1940; reposited in the UCMP

Collection methods: surface (float)

Primary reference: C. L. Camp. 1942. Ichthyosaur rostra from central California. Journal of Paleontology 16(3):362-371 [M. Carrano/H. Street]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 185384: authorized by Matthew Clapham, entered by Matthew Clapham on 21.04.2017

Creative Commons license: CC BY (attribution)

Taxonomic list

 Ichthyosauria - Ichthyosauridae
Ichthyosaurus californicus n. sp. Camp 1942 ichthyosaur