Radian

The rapid evolution of burrowing worms led to the collapse of the microbial mat ecosystems that dominated the Ediacaran period. While, in our timeline, this would spell the doom of the Ediacara biota, the delayed evolution of worms meant that Vendozoans were still in a position to dominate the new ecosystems - although they would now have to compete with new bilaterian clades.

The complete reshaping of the ecosystems would bring with it new evolutionary pressures, forcing life to diversify beyond anything known to that point. After the Ediacaran-Radian mass extinction would come a second major adaptative radiation in the Early Radian - pushing Vendozoans to new frontiers. This is where the first major phyla would begin to take shape, with new body plans being created.

The Middle Radian would see the rise of the first superpredators, sending the fauna into an evolutionary arms race and giving rise to new, more specialized lineages.