| Range |
~1,500 MYA
|
| Organism |
Eukaryotic fossil acritarch Tappania plana |
| Reference |
Javaux EJ, Knoll AH, Walter MR. Morphological and ecological complexity in early eukaryotic ecosystems. Nature. 2001 Jul 5 412(6842):66-9. DOI: 10.1038/35083562 abstract, p.67 left column bottom paragraph & p.69 left column 2nd paragraphPubMed ID11452306
|
| Method |
P.68 left column 2nd paragraph: "U–Pb SHRIMP [sensitive high-resolution ion microprobe] analyses of zircons [a mineral belonging to the group of nesosilicates] from an ash bed in the Mainoru Formation fix an age of 1,492±3 Myr for early Roper deposition [ref 13]. A 1,429±31 Myr Rb–Sr age for illite in dolomitic siltstones near the top of the succession [ref 14] is consistent with the zircon age, albeit less reliable." |
| Comments |
P.69 left column 2nd paragraph: "Process-bearing microfossils were once thought to be restricted to Phanerozoic strata. Two decades ago, their range was extended to the beginning of the Neoproterozoic era. Now, it is clear that process-bearing microfossils have been present for nearly half of life's recorded history. The Roper [Northern Territory, Australia] Group provides an unusually clear window on aspects of biology in the early Mesoproterozoic oceans, demonstrating that 1,500 Myr ago marine protists included cytologically sophisticated organisms that lived in ecologically differentiated communities." |
| Entered by |
Uri M |
| ID |
113025 |