Proterozoic
Pre-complex life era
Proterozoic refers to the geological eon spanning roughly 2.5 billion to 541 million years ago, between the Archean and Phanerozoic eons.
During this vast stretch, Earth's atmosphere gained oxygen, complex single-celled life emerged, and the first multicellular organisms appeared.
Proterozoic rocks and Proterozoic fossils describe materials from this period.
Layered sedimentary bacterial structures
- cyanobacteriaPhotosynthetic bacteria producing oxygen
- eukaryotesNuclear-membrane organisms
- algaePrimitive aquatic photosynthesizers
- multicellularHaving multiple cells
Earliest geological eon
- ArcheanEarliest geological eon
- deep timeImmense spans of Earth's history
- geologic timeEarth's age measured epochally
- billion yearsThousand million revolutions around sun
Adding breathable gas
- glaciationIce sheet spreading process
- ColumbiaAmerica personified, or its namesakes
- supercontinentCombined planetary landmass
- riftingGeological spreading apart
Stable ancient continental core
- shieldHandheld defensive armor
- basementSubterranean building level
- gneissFoliated metamorphic rock
- metamorphicUndergoing structural change
Life from inanimate matter
- prebioticNutrient for gut bacteria
- hydrothermal ventsSubmarine volcanic water jets
- primordialExisting from the start
- amino acidsOrganic compounds forming proteins
nucleotides · self-replication · metabolism · anoxic · chirality
stromatolites
Layered sedimentary bacterial structures
- cyanobacteriaPhotosynthetic bacteria producing oxygen
- eukaryotesNuclear-membrane organisms
- algaePrimitive aquatic photosynthesizers
multicellular · microfossils · biomarkers · photosynthesis · soft-bodied
Precambrian
Earliest geological eon
- ArcheanEarliest geological eon
- deep timeImmense spans of Earth's history
- geologic timeEarth's age measured epochally
oxygenation
Adding breathable gas
- glaciationIce sheet spreading process
- ColumbiaAmerica personified, or its namesakes
- supercontinentCombined planetary landmass
craton
Stable ancient continental core
abiogenesis
Life from inanimate matter
- prebioticNutrient for gut bacteria
- hydrothermal ventsSubmarine volcanic water jets
- primordialExisting from the start
amino acids · nucleotides · self-replication · metabolism · anoxic · chirality