Period Ordovician Period

Time runs left (older) → right (younger) · Hover a card for details

Marine invertebrates diversify; first mass extinction (485-444 Ma).

485.40 Ma – 443.80 Ma · 41.60 Ma duration

Axis labels in Ma (millions of years ago) · Click a card for details

Ordovician Period 2

470 Ma First Coral Reefs Ordovician reef systems First significant coral-stromatoporoid reef systems in shallow Ordovician seas.
443.8 Ma End-Ordovician Extinction First major mass extinction Two-phase extinction driven by glaciation and sea level fall; ~85% of marine species lost.

100%

Density