GEOLOGIC TIME SCALE
TIME
DURATION
EON ERA PERIOD EPOCH TIME SPAN (million
HIGHLIGHT
years)
Hadean 4,567 to 536 Named after Hades, was marked by intense volcanism and heavy asteroid impacts
4,031 Ma
Archean 4,031 to 1531 The first single-celled organisms appeared as well as the first cyanobacteria, which began to produce oxygen.
2,500 Ma
Proterozoic 2,500 to 1961 First appearance of animals during this time and development of the first multicellular organisms.
538.8 Ma
Phanerozoic 538 to 0 Ma 538 It is the eon in which we live, and is characterized by the emergence of all major groups of plants and animals.
Paleozoic 541 to 252 Ma Earth's continents were combined into a single supercontinent called Pangaea.
Refferences: Cambrian 541-485.4 Marine arthropods were the most common animals of the time
https://en.wiki Ordovician 485.4-443 The first coral reefs appeared during this time, and fish became more common.
Silurian 443.8-419 The first jawed fish as well as the first land animals, such as insects and scorpions.
pedia.org/wiki/
Devonian 419.2-358 First amphibians appeared during this time, and land plants began to spread widely.
Geologic_time
Carboniferous 358.9-298 Vast amounts of coal use today were formed from plants that lived during this time.
_scale Permian 298.9-252 Ended with the largest mass extinction in Earth's history, which killed off about 90% of all marine life.
https://www.g Mesozoic 252 to 66 Ma "age of dinosaurs." During this time, dinosaurs were the dominant land animals on Earth.
Triassic 252.2-201. The first dinosaurs appeared during this time.
eologyin.com/
Jurassic 201.3-145 Dinosaurs were the dominant land animals of the time and the climate became warmer.
2014/12/geolo
Cretaceous 145-66 Ended with the second-largest mass extinction in Earth's history, killed off all dinosaurs except for birds.
gic-time-scale-
Cenozoic 66 Ma to present Great diversity among mammals, and is also marked by the rise of human civilization.
major-eons-
Paleogene 66-23.03 It was a time of recovery from the Cretaceous mass extinction, the first primates appeared.
eras.html Paleocene 66.0-56.0 Began with the extinction of the dinosaurs and ended with the rise of the first mammals and birds.
Eocene 56.0-33.9 Warm, wet climates and lush forests.
Oligocene 33.9-23.0 Time of cooling and drying climates
Neogene 23.03-2.58 The first hominins appeared during this time, as well as the first grasses.
Miocene 23.0-5.3 Continued cooling and drying climates. Hominins began to walk upright.
Pliocene 5.3-2.6 Hominins became more diverse during this time, and the first Homo species appeared.
Quarternary 2.58 million Humans evolved and became the dominant species on Earth. The Quaternary Period is also known for its ice ages.
years ago to
present
Pleistocene 2.6 ma Characterized by a series of ice ages and interglacial periods. Humans evolved during this time.
Holocene 11,700 ago It has been a time of relatively stable climates and human expansion.
CODING
EON (Blue)
ATIBAGOS, ANAFE S.
ERA (Yellow)
PERIOD (Green)
BSE ED SCIENCE 3
EPOCH (Red)
