Cambrian Explosion
538.8 million years ago · Prehistoric
Approximately 538.8 million years ago, a rapid diversification of multicellular animal life began in what is known as the Cambrian Explosion. Within a geologically brief period of 13–25 million years, nearly all major animal phyla appeared in the fossil record, including the emergence of hard body parts, complex sensory systems, and novel ecological relationships. The causes remain debated, with hypotheses including rising atmospheric oxygen, new predator-prey dynamics, and genetic regulatory changes. This diversification established the foundation for modern marine biodiversity.
Key Figures
Charles Doolittle WalcottHarry WhittingtonSimon Conway MorrisDerek BriggsGraham BuddHou Xianguang
Locations
Burgess ShaleChengjiang Fossil SiteMaotianshan ShalesSirius Passet
Topics
Cambrianbiodiversityevolutiondiversificationspeciation
Connected Events — 6 Connections
Enabled by atmospheric oxygen increase from Great Oxidation Event
Established biodiversity later disrupted by Chicxulub Impact: Mass Extinction
Destroyed much of the marine biodiversity that had diversified since the Cambrian radiation Permian-Triassic Extinction: The End-Permian Die-Off
Burgess Shale fossils document the extraordinary diversity of the Cambrian radiation in unprecedented detail Burgess Shale Fossils Discovered by Walcott
Initiated evolutionary lineage culminating in Earliest Evidence of Life on Earth
The Ordovician extinction devastated the marine biodiversity that had flourished since the Cambrian Explosion roughly 90 million years earlier Late Ordovician Glaciation and Mass Extinction
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