| Phanerozoic
EON
(544 mya to present) "The
age of visible life" |
ERA |
Periods |
EPOCH |
Evolutionary
Milstones |
|
Cenozoic
Era
(65 mya to today) |
Quaternary
(1.8 mya to today) | Holocene
(11,000 years to today) |
Last
major ice age ends. Modern man migrates to the Americas. |
| Pleistocene
(1.8 mya to 11,000 yrs) |
Neandertals
appear and disappear; Homo erectus and Homo sapiens appear. |
| Tertiary
(65 to 1.8 mya) | Pliocene
(5 to 1.8 mya) |
Ape-like
ancestors of modern humans (Hominids); the Australopithecines
appear and disappear. Homo habilis lives from 2.5 to 1.8
mya. |
| Miocene
(23 to 5 mya) | Grazing
horses, antelopes appear |
| Oligocene
(38 to 23 mya) |
Radiation
of more modern animals: most modern bird forms have appeared; most modern mammals
have appeared. |
| Eocene
(54 to 37 mya) | First
grasses appear, a resource for herbovores; trees thrive. Some modern mammals appear:
advanced primates; camels, cats, dogs, horses & rodents |
| Paleocene
(65 to 54 mya) | Flowering
plants begin radiation extending through the Eocene. Small mammals radiate |
Mesozoic
Era
(245 to 65 mya) |
Cretaceous
(146 to 65 mya) |
Divided
as: Upper; Middle; Lower |
Major extinction
includes dinosaurs and ammonites (K-T)
Appearances include: flowering plants
(angiosperms); lizards; placental animals (early mammals); snakes; social insects;
marsupial and primitive placental animals
Modern insect forms radiate
|
| Jurassic
(208 to 146 mya) | Appearances
include birds; crabs; frogs and salamanders
Dinosaurs radiate to dominate the land
|
| Triassic
(245 to 208 mya) | Breakup
of Pangaea begins
Major extinction event: tabulate corals and conodonts disappear
- ammonoids, reptiles and amphibians decimated
Appearances include: dinosaurs;
crocodiles; marine reptiles; turtles; Pterosauria
and mammals
Major groups of seed plants appear |
|
Paleozoic
Era
(544 to 245 mya) |
Permian
(286 to 245 mya)
|
Major extinction
of invertebrates (P-T). Trilobites fade away
forever. All
but articulate crinoids dissapear
Seedplants
producing large trees |
|
Carboniferous
(360 to 286 mya) | Pennsylvanian
(325 to 286 mya) | Conifers
& many winged insects appear |
| Mississippian
(360 to 325 mya) | Reptiles
appear. Trilobites become scarce |
| Devonian
(410 to 360 mya) | Mass
extinction (F-F)
Land colonized by plants and animals
Appearances include:
insects; sharks; amphibians (tetrapods); lung fishes
and earliest seed plants.
Extensive radiation of fishes. |
| Silurian
(440 to 410 mya) | Jawed
fish, cartilaginous fish and vascular plants appear. Primitive terrestrial predators:
Arachnids. |
| Ordovician
(500 to 440 mya) | Mass
extinction
First land plants; bryozoans appear. Trilobites begin to specialize. |
| Cambrian
(544 to 500 mya) | Tommotian
(530 to 527 mya) | Appearance
of hard parts and vision - fossils become common. Appearances include: vertebrates;
jawless fish; small shelly animals; conodonts; trilobites
radiate repeatedly and reach their peak diversity. | First
major radiation of animals |
|
Precambrian
Time
(4,500 to 544 mya) "deep
time on earth" |
Proterozoic
Era
(2500 to 544 mya) |
Vendian
(650 to 544 mya) or Ediacaran |
No
Epochs |
Extinction
at end of Vendian
Macroscopic, soft-bodied organisms radiating.
Oldest metazoans
(multicellular animals) - Ediacaran Fauna. |
| Neoproterozoic
(900 to 544 mya) - Late |
Macroscopic
fossils of soft-bodied organisms.
Chloroblasts arise from cyanobacteria
through endosymbiosis.
Stromatolite diminishing. |
| Mesoproterozoic
(1600 to 900 mya) - Middle | Sexual
reproduction appears (about 1 billion years ago)
First land fungi |
| Paleoproterozoic
(2500 to 1600 mya) - Early | More
complex
single-celled life with aerobic metabolism begin diversification
Rusting of
earth, depletion of oceanic Fe in banded iron formations
Peak of stromatolite
with cyanobacteria oxygenating the atmosphere |
| Archaean
(3800 to 2500 mya) |
Primitive
Eukarya appear
Photosynthesis
appears
Oldest fossils - Apex Chert of Australia (3.55 BYA) - Prokaryotes
dominate (Eubacteria and Archaea);
simple cell forms form stromatolite
First life
appears - Heterotrophic, anerobic, Asexual
Oldest sedimentary
rocks (3.8 BYA) |
Hadean
(4500 to 3800 mya) | Earth's
environment extremely hostile to life as we know it |
