It is suggested that analysis of sedimentary pyrite from the Belingwe sedimentary basin in Zimbabwe may provide evidence for bacterial reduction at this date.
2,500,000,000 to 542,000,000 years ago The Proterozoic Eon: the most recent part of the Precambrian Supereon.
) 13,800,000,000 (13.8 billion) years ago The creation of the universe according to present estimates of "big bang" - "Stephen Hawkings and others...
estimate between 18 and 11 billion with 13.8 being the closest estimation".
is Galena (lead sulfide) formed as pockets or veins in carbonate rock into which the mineral bearing fluid rock has intruded.
All of the major animal groups of the Ordovician oceans survived, including trilobites, "When I view all beings not as special creations, but as the lineal descendants of some few beings which lived long before the first bed of the Silurian system was deposited, they seem to me to become ennobled.
Judging from the past we may safely infer that not one living species will transmit its unaltered likeness to distant futurity." (Charles Darwin) From primal swamp to speaking humans: Ernst Haeckel said (1903) that the Pithecoiden (monkey) theory of human evolution requires tracing our animal ancestors before monkeys.
The end-Frasnian extinction (the largest) about 375 million years ago.
The about 365 million years ago during the Famennian.