Saucito Rancho (Miocene of the United States)

Where: California (36.6° N, 121.9° W: paleocoordinates 36.1° N, 119.1° W)

• coordinate based on political unit

When: Canyon del Rey Diatomite Member (Monterey Formation), Tortonian (11.6 - 7.2 Ma)

• early late Miocene according to Demere et al. 2005

•The original description states that the “top stratum” of the section in which the specimen was found “is loose and scarcely consolidated, characters which accompany the upper part of the Monterey shale member whenever definitely exposed” [67: 238]. Barron [68] placed a rock sample (CAS 866) from the type locality, collected at the same time as the CAS 1733, into the Canyon del Rey Diatomite Member. Fission-track dating of associated ash layers place the base of this unit at 11.3 ± 0.9 Ma [69]. A second ash horizon from within the Canyon del Rey Diatomite Member has been dated to 8.4 ± 0.8 Ma, but it is unclear whether the holotype was retrieved from above or below this horizon The rock sample (CAS 866) apparently associated with the holotype has yielded the diatom Denticulopsis lauta [68], which last appears around 9–10 Ma [70, 71]. Together, these observations imply an early Tortonian (11.6–9.5 Ma) age for B. ryani. (Marx & Forcye, 2015)

• member-level stratigraphic resolution

Environment/lithology: basinal (); lithified, condensed, diatomaceous shale

• deep Pacific basin
• "The strata of the exposure dip to the westward at an angle of about 45 degrees, and the strike is northeast. The buildings [whose foundation is the locality of the specimen] are erectedat the base of a steep incline on the west side of a creek, the slope being composed of diatomaceous earth. The top stratum is loose and scarcely consolidated, characters which accompany the upper part of the Monterey shale member wherever definitely exposed. Below this loose, purer grade of material, there is exposed about 75 feet of thinly bedded, more consolidated earth with occasionally some "opalized" or "flinty" shale

Size class: macrofossils

Preservation: original phosphate

Reposited in the CAS

Collection methods: salvage,

Primary reference: G. D. Hanna and M. McLellan. 1924. A new species of whale from the type locality of the Monterey Group. Proceedings of the California Academy of Sciences 13(14):237-241 [M. Uhen/N. Pyenson/N. Pyenson]more details

Purpose of describing collection: taphonomic analysis

PaleoDB collection 45501: authorized by Mark Uhen, entered by Nick Pyenson on 26.10.2004, edited by Mark Uhen

Creative Commons license: CC BY (attribution)

Taxonomic list

Mammalia
 Balaenopteroidea - Balaenopteridae
"Balaenoptera" ryani Hanna and McLellan 1924 rorqual
CAS 1733