-
Precambrian Era 4600-570MYA
-fossils extemely rare
-primative aquatic plants -
Period: to
Geologic Timescale Mrs. Edenstrom Sara Stijovic
Geologic history of the Earth. -
Cambrian Period 570-500MYA
The Cambrian period had an abundant amount of marine organisms and the earth was covered with ocean. The entire life was in the ocean.
-trilobites are dominant -
Ordovician period 500-444MYA
During this period, the area north of the tropics was almost entirely ocean, and most of the world's land was collected into the southern supercontinent Gondwana.
The Ordovician is best known for its diverse marine invertebras (graptolites, trilobites...)
When Gondwana settled on the South Pole, the massive glaciers formed, causing shallow seas to drain and sea levels to drop. This caused mass extinction that characterize the end of the Ordovician in which the 85% of species went extinct. -
Silurian Period 444-419MYA
As with other geologic periods, rock beds that define period's start and end are well identified, biut the exact dates are not certain by several milion years. The base of the Silurian isset at a major extinction event when 60% of marine species were wiped out. -
Devonian Period 419-360MYA
The vegetation of the early Devonian consisted primarily of small plants, the tallest being only a meter tall. By the end of the Devonian, ferns, horsetails, seed plants and first gorest has appeared. During the Devonian, two major animal groups colonized the land: tetrapods and terrerstrial athropods. during this period, significant changes in the world's geography took place:the world's land was collected into two supercontinents, Gondwana and Euramerica.
-mass extinction event in the end -
Carboniferous Period 360-299MYA
-several major biological, geological and climatic events occured during this time; one of the greatest evolutionary innovations of the Carboniferous is amniote egg: it gave the ancestors of birds, mammals, and reptiles
-in the beginning, the period had uniform, tropical and humid climate -fewer corals, crinoids, blastoids, cryozoans...gastropod, bony fish, and shark diversity -
Paleozoic Era 570-225MYA
-Cambrian,
-ordovician,
-Silurian,
-Devonian,
-Carboniferous,
-Permian. -
Permian Period 280-225 MYA
- the great forests of fern-like plants shifted to gymnosperms, plants with their offspring enclosed within seeds. Modern conifers, the most familiar gymnosperms of today, first appear in the fossil record of the Permian. The Permian was a time of great changes and life on Earth was never the same again. -extinction of many species of marine life, including trilobites -little change in terrestial animals
-
Triassic Period 225-195MYA
-the great forests of fern-like plants shifted to gymnosperms, plants with their offspring enclosed within seeds. Modern conifers, the most familiar gymnosperms of today, first appear in the fossil record of the Permian. The Permian was a time of great changes and life on Earth was never the same again.
-abundant cycades and conifers
-the period of T-rex -
Jurassic Period 195-136 MYA
-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
-abundant cycades and conifers -
Cretaceous Period 136-65 MYA
-the first appearance of the flowering plants, also called the angiosperms or Anthophyta
-the oldest known ants and butterflies. Aphids, grasshoppers, and gall wasps appear in the Cretaceous, as well as termites and ants in the later part of this period. Another important insect to evolve was the eusocial bee, which was integral to the ecology and evolution of flowering plants
-climax of dinosaurs and ammonites-followed by extinction
-great development of bony fish -
Mesozoic Era 225-65 MYA
-Triassic,
-Jurassic,
-Cretaceous. -
Tertiary Period 65-63.2 MYA
-earliest placental mammals, modern mammals, and large mammals
It spanned the transition from a globally warm world containing relatively high sea levels and dominated by reptiles to a world of polar glaciation, sharply differentiated climate zones, and mammalian dominance. It began in the aftermath of the mass extinction event that occurred at the very end of the Cretaceous Period (the so-called K-T boundary), when as much as 80 percent of species, including the dinosaurs, disappeared. -
Quarternary Period 1.8 MYA-present
-large carnivores, neanderthals, humans, mastodons
-Many genera and even species of shellfish, insects, marine microfossils, and terrestrial mammals living today are similar or identical to their Pleistocene ancestors
-Ice age extinctions were not democratic. Most of the animals that became extinct at the end of the Pleistocene -
Cenozoic Era 65 MYA-present
-Tertiary,
-Quartenary.
