Before the Cambian explosion there was the Avalon explosion. Following the Cryogenia period, sometimes called snowball earth oxygen levels rose, thanks to cyanobacteria, giving rise to creatures so unlike any alive today that they may be a...See moreBefore the Cambian explosion there was the Avalon explosion. Following the Cryogenia period, sometimes called snowball earth oxygen levels rose, thanks to cyanobacteria, giving rise to creatures so unlike any alive today that they may be a separate kingdom from plants and animals. Written by
David Foss
See less