4600 Million Years ago
|
PRE - CAMBRIAN - Greatest part of geological time. Earth crust, land
masses, seas formed. Great volcanic activity. Fossils generally rare.
|
590 Million Years ago
|
CAMBRIAN - Sudden appearance of many fossils. Widespread life in early
shallow seas. Trilobites very common. |
500 Million Years ago
|
ORDOVICIAN - Mild climate over much of earth, still covered mostly
in sea. Sedimentation, mountain building. Reef building, coral, algae,
sponges, molluscs abundant. |
440 Million Years ago
|
SILURIAN - Evolution of jaw less fishes, first vertebrates. Growth
of first land plants. |
408 Million Years ago
|
DEVONIAN - Peak of mountain building. Explosive evolution. First land
creatures, amphibians, evolved. |
360 Million Years ago
|
CARBONIFEROUS - Richly forested swamps and deltas. North America and
Europe submerged to form large coal fields. Extensive glaciation. Insects
thrived. First reptiles appear. |
286 Million Years ago
|
PERMIAN - Desert over much of Pangaea. Reptiles widespread, insects
evolved. Several marine creatures became extinct, new land flora, conifers
evolved. |
248 Million Years ago
|
TRIASSIC - Pangaea begins to break up. Conifers dominant plants. Great
diversity among reptiles, first dinosaurs and giant marine reptiles appear.
Small primitive mammals evolve. |
213 Million Years ago
|
JURASSIC - Large volcanic activity opens Atlantic Ocean. Dinosaurs
widespread. Air first conquered by flying reptiles and primitive birds.
Early flowering plants appear. |
144 Million Years ago
|
CRETACEOUS - Great deposits of chalk formed in Britain. Dinosaurs and
large reptiles become extinct at the end of this period. First true birds
and early mammals become numerous. |
65 Million Years ago
|
TERTIARY - Explosive growth of mammals. Many large species evolve but
most die out. Flowering plants widespread, climate cools, grasslands appear.
Considerable uplift of land occurs. |
2 Million Years ago - present
|
QUATERNARY - Latest geological period continues up to this very day.
Marked by climatic changes, 4 major ice ages alternated with warmer periods.
Mammals increased and adapted. Man evolves to dominate earth. |