La Pantera II ( of Mexico)

Also known as GTO-12B

Where: Guanajuato, Mexico (21.1° N, 100.8° W: paleocoordinates 21.2° N, 100.2° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Rancho Viejo Beds Formation, Blancan (4.9 - 1.8 Ma)

• correlated with chron C2An.2r; immediately overlies a fission track on zircon date of 3.9 +/- 0.3 Ma

• bed-level stratigraphic resolution

Environment/lithology: fluvial; poorly lithified, gray, green, white, silty, sandy claystone

• the beds "probably were deposited as point bar sequences in a meandering river channel and as adjacent floodplain deposits"
• "The sedimentary and volcaniclastic Rancho Viejo Beds are green to gray to white, weakly indurated, friable, clays and silty to sandy clays, with variable sand, gravel, and tuffaceous components."

Size class: macrofossils

Primary reference: J. J. Flynn, B. J. Kowallis, C. Nuñez, O. Carranza-Castañeda, W. E. Miller, C. C. Swisher, III, and E. Lindsay. 2005. Geochronology of Hemphillian-Blancan aged strata, Guanajuato, Mexico, and implications for the timing of the Great American Biotic Interchange. Journal of Geology 113:287-307 [J. Alroy/J. Alroy/M. Uhen]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 70112: authorized by John Alroy, entered by John Alroy on 17.03.2007

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Amphibia
 Salientia - Ranidae
Rana sp.
Rana sp. Linnaeus 1758 frog