These familiar marine arthropods first arose about 545 million years ago in the early Cambrian and thrived throughout the world's oceans until they were wiped out in the Permian extinctions about ...

Others propose that an extinction of life just before the Cambrian opened up ecological roles, or "adaptive space," that the new forms exploited. External, ecological factors like these were ...

While many scientists think that they subsequently evolved into new forms of animals that continued into the Cambrian period, others say that they were wiped out by extinction. 800 mya ...

The archaic sponge reef-dwellers of the Cambrian gave way to bryozoans ... This resulted in the second largest mass extinction of all time, wiping out at least half of all marine animal species ...

This is exemplified by the well-known mass extinction events and associated ... resolution diversity curve of Proterozoic and early Cambrian eukaryotic fossil species. The findings revealed ...

which navigated through multiple cycles of flourishing and extinction, culminating in the emergence of a complex ecosystem characterized by the iconic Cambrian explosion when a wide variety of ...