Where: Sonora, Mexico (30.4° N, 112.0° W: paleocoordinates 40.8° S, 134.0° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Clemente Formation, Ediacaran (635.0 - 541.0 Ma)

• The Clemente Formation fossils cannot be radiometrically dated, however, an age estimate can be made owing to the presence of the trace fossil Vermiforma antiqua in siltstone of the Clemente Formation deposited above the Clemente oolite. This fossil is biogenic and conspecific with V. antiqua from strata of the Carolina Slate Belt. The age of V. antiqua in North Carolina is bracketed

•by U-Pb radiometric dates. Accepting these dates and their error ranges as valid indicates an age for the North Carolina V. antiqua fossils of between 576 and 640 million years. But since the fossil occurrence is stratigraphically much closer to volcanic rocks associated with the latter date, it is likely that the age of the fossils is close to, or in excess of, 600 million years.

• group of beds-level stratigraphic resolution

Environment/lithology: coastal; lithified siltstone

Size classes: macrofossils, mesofossils

• The fossils include three types of body fossils, two ichnofossils, and several enigmatic forms that have been reported elsewhere [McMenamin et al. (1992) Int. Geol. Congress, Kyoto Vol. 2, p.257(abstr.)]

Preservation: trace

Collection methods: quarrying,

Primary reference: M. A. S. McMenamin. 1996. Ediacaran biota from Sonora, Mexico. Proceedings of the National Academy of Sciences 93(10):4990-4993 [W. Kiessling/M. Domansky]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 113595: authorized by Wolfgang Kiessling, entered by Marcus Domansky on 02.08.2011

Creative Commons license: CC BY (attribution)