Geological Eons and Periods

Flashcards covering geological eons and periods, key dates, notable organisms, and milestones in the history of life on Earth.

EON HADÉEN

3.8-4.57 billion years ago; marks the beginning of the solar system.

EON ARCHÉEN

2.5-3.8 billion years ago; characterized by the first traces of life and stromatolites.

Stromatolites

The first fossils known, primarily formed by cyanobacteria.

3.5 billion years ago

EON PROTÉROZOÏQUE

0.542-2.5 billion years ago; noted for the emergence of eukaryotes and multicellular organisms.

Eukaryotes

First appeared between 1.7-1.9 billion years ago in Gabon.

Homoese naturelle chez bilateria

585 million years ago.

EON PHANÉROZOÏQUE

542 million years ago to present; includes significant biological milestones like the Cambrian explosion.

PÉRIODE CAMBRIEN

Occurred around 542 million years ago; associated with the first fossils of bilateria.

PÉRIODE ORDOVICIAN

Lasted approximately 488 million years ago.

PÉRIODE SILURIAN

Lasted approximately 444 million years ago.

PÉRIODE DEVONIAN

Lasted approximately 416 million years ago.

PÉRIODE CARBONIFEROUS

Lasted approximately 359 million years ago.

PÉRIODE PERMIAN

Lasted approximately 299 million years ago.

PÉRIODE TRIASSIC

Lasted approximately 251 million years ago.

PÉRIODE JURASSIQUE

Lasted approximately 200 million years ago.

PÉRIODE CRETACEOUS

Lasted approximately 146 million years ago.

PÉRIODE TERTIARY

Lasted approximately 65 million years ago.

LUCA

The last universal common ancestor; indicated by the earliest fossils of plants. archéan era

apparition de l’homéose naturelle chez les arthropodes

540 million years ago; cambrien period

first fossiles of metazoic embryos

580 million years ago

appeared during the proterozoic era

• chenjiang and burgess

• site: Doushantuo

• Burgess: marella, yohoia, odaria

• Chen Jiang: allantospongia (éponge), trilobites

first multicellular organisms

620-575 mya

fossiles from cambrien

arthropodes, mollusques, échinodermes, chordés, nématodes, brachiopodes, cnidaires, cténaires, éponges

first metazoa fossil

• 575 million years ago; eon proterozoic

• ediacara

  • taxon: kimberella

  • phylum: Lophotrochozoa

cambrien explosion

530-542 million years ago

sudden appearance of most of the big branches of metazoa

metazoa

600 million years ago (proterozoic eon)

Les métazoaires sont des Eucaryotes (Unicontes Opisthocontes) multicellulaires mobiles hétérotrophes.