Period

Million Years Ago

Major Events

Primary Victims

Species Killed *

Neogene

.01

Glacial event
Humans evolve

Plankton, marine invertebrates, mammals

60 - 80% (?)

Paleogene

24

Climatic cooling

Plankton, mammals
Plankton, marine invertebrates, mammals

?
?

Cretaceous

65

Flowering plants dominate land

Plankton, marine invertebrates, reef
builders, marine reptiles, dinosaurs
Marine invertebrates

65 - 70%
?

Jurassic

144




213

Earliest birds evolve

Marine invertebrates, dinosaurs


Marine invertebrates

Marine invertebrates, mammal-like reptiles

?

80% of Bivalves

?

Triassic

248

Earliest mammals evolve
Minor glacial event

-

-

Permian

-

-

Sea-floor protozoans, marine invertebrates, reef builders, mammal-like reptiles

75 - 90% of main victims

Pennsylvanian

286

-

-

-

Mississippian

320

360

Earliest reptiles evolve

Vertebrates invade land

-

-

Devonian

408

Glacial event




Land plants become conspicuous

Plankton, marine invertebrates, reef builders, primitive fish

70% of invertebrates

Silurian

438

Glacial event

Marine invertebrates, reef builders

80 - 95% (?)

Ordovician

505

Earliest fish evolve

Marine invertebrates (trilobites)

80 - 90% (?)

Cambrian

590

Great diversification of sea life

-

-

Pre-Cambrian

650

Glacial event

Acritarchs (algae)

70%