-
Cambrian 570 M-500 M
The period gets its name from Cambria, the Roman name for Wales, where Adam Sedgwick, one of the pioneers of geology, studied rock strata. Charles Darwin was one of his students.
Trilobites were the dominant species. -
Period: to
Geologic Timescale
-
Ordovician 500M- 435 M
For the most part the Earth's climate was warm and wet.
Most of the world's landmasses came together to create the supercontinent of Gondwana, which included the continents of Africa, South America, Antarctica, and Australia. -
Silurian 435 M- 395M
The Paleozoic era's Silurian period saw animals and plants finally emerge on land. But first there was a period of biological regrouping following the disastrous climax to the Ordovician.
Tiktaalik Eurypterids develop -
Devonian 395 M- 345M
During the Devonian there were important changes in the land masses on the globe. North America and Europe had collided forming a large continent called Euramerica. This caused the formation of the Appalachian Mountain Range. The other large land mass was Gondwana. It was made up of South America, Africa, Antarctica, India and Australia. Armored fish go extinct, but abundance of several species of fish. Earliest amphibians and ammonites. -
Carboniferous 345M-280M
In addition to having the ideal conditions for the formation of coal, several major biological, geological, and climatic events occurred during this time. Biologically, we see one of the greatest evolutionary innovations of the Carboniferous: the amniote egg, which allowed for the further exploitation of the land by certain tetrapods. It gave the ancestors of birds, mammals, and reptiles the ability to lay their eggs on land without fear of desiccation. -
Permian 280 M-225M
During the Permian all the world's land masses joined together into a single supercontinent, Pangea. Unlike most other geological periods which have a three-part division into early, middle, and late, the Permian Period was conventionally divided into early and late only. The warm shallow oceans swarmed with many kinds of life, basically very similar to Carboniferous forms. -
Triassic- 225M-195M
In many ways, the Triassic was a time of transition. It was at this time that the world-continent of Pangaea existed, altering global climate and ocean circulation. The Triassic also follows the largest extinction event in the history of life, and so is a time when the survivors of that event spread and recolonized. -
Jurassic - 195M-136M
Great plant-eating dinosaurs roaming the earth, feeding on lush ferns and palm-like cycads and bennettitaleans … smaller but vicious carnivores stalking the great herbivores … oceans full of fish, squid, and coiled ammonites, plus great ichthyosaurs and long-necked plesiosaurs … vertebrates taking to the air, like the pterosaurs and the first birds. This was the Jurassic Period, 199.6 to 145.5 million years ago — a 54-million-year chunk of the Mesozoic Era. -
Cretaceous - 136M-65M
The Cretaceous is usually noted for being the last portion of the "Age of Dinosaurs", but that does not mean that new kinds of dinosaurs did not appear then. It is during the Cretaceous that the first ceratopsian and pachycepalosaurid dinosaurs appeared. Also during this time, we find the first fossils of many insect groups, modern mammal and bird groups, and the first flowering plants. -
Tertiary - 65 M- 1.8M
The climate change from the beginning to the end of the time period was very significant. In the beginning, the Earth was warm and moist compared to the weather now. But, by the middle of the period, the Earth had started to cool.After the previous time period (the Cretaceous) ended with the extinction of dinosaurs, large reptiles, and many other animals, mammals no longer faced as much competition. Mammals became the dominant species on Earth. -
Quaternary - 1.8 M – Present
The Quaternary period, which began about 1.8 million years ago (1,800,000 years ago), is still going on today - we live in the Quaternary period. So far, it's a much shorter period than the others. At the beginning of the Quaternary period, early people in Africa were already using stone tools. The climate was mostly on the cooler side, with ice ages coming and going every forty thousand years or so. Among the bigger mammals were saber-toothed tigers, mammoths and mastodons, humans...
