Also known as float, Tinu Formation, Oaxaca, Mexico - Robison and Pantoja-Alor 1968.

Where: Oaxaca, Mexico (17.0° N, 96.6° W: paleocoordinates 16.8° S, 105.5° W)

• outcrop-level geographic resolution

When: Saukia zone, lower Member (Tinu Formation), Tremadoc (486.5 - 477.7 Ma)

• Specimens found about 2m above the base of the Tinu Formation.

• member-level stratigraphic resolution

Environment/lithology: lithified, silty limestone

Size class: macrofossils

Collection methods: The fauna correlate (approximately) with the North American Saukia Zone (Late Cambrian), and with the lower Tremadoc of Europe and South America. However, probably less than 20% of the trilobite genera from the Tinu Formation have been reported from rocks either younger or older than the Tremadoc. On an end note, Robison talks of the differing opinions on the relative age placement of the Saukia Zone fauna. Conclusions are that the European Saukia Zone and those found in Mexico have an age of Early Ordovician and not Late Cambrian as determied for the ""North American Saukia Zone"".

Primary reference: R. A. Robison and J. Pantoja-Alor. 1968. Tremadocian trilobites from the Nochixtlan Region, Oaxaca, Mexico. Journal of Paleontology 42(3):767-800 [M. Patzkowsky/P. Borkow]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 9852: authorized by Mark Patzkowsky, entered by Phil Borkow on 24.01.2001

Creative Commons license: CC BY (attribution)