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)
Taxonomic list
Aspidella terranovica | |
"cf. Cyclomedusa plana" = Aspidella terranovica
"cf. Cyclomedusa plana" = Aspidella terranovica Billings 1872 | |
Lockeia sp. James 1879
Palaeophycus tubularis Hall 1847 | |
Sekwia | |
Sekwia sp. Hofmann 1981 |