The Cambrian began about 538.8 million years ago. Over roughly its first 20 million years, animal body plans and ways of life diversified rapidly. Some lineages already existed in the Ediacaran, so this “explosion” was an extended diversification, not an instant origin of life.
Annual surface temperature from CESM (T): a model estimate, not a direct observation of the past.
0 Ma: pre-industrial climate/CO₂; modern sea-level and O₂ references.
Glacial-interglacial cycles with 120m+ sea level swings. Homo sapiens spread from Africa across the globe, and most megafauna went extinct.
Annual model means · 0 Ma: pre-industrial
Present