age of paleozoic
The Cambrian spans from 541 million years to 485 million years and is the first period of the Paleozoic Era of the Phanerozoic Eon. The Cambrian marked a boom in evolution in an event known as the Cambrian Explosion in which the largest number of creatures evolved in any single period of the history of the Earth. Marine and nonmarine sedimentary rocks of Paleozoic age underlie all of Kansas. All the systems of the Paleozoic Era are recognized (Pl. 1). In the eastern part of the State, upper Paleozoic rocks that are chiefly Permian and Pennsylvanian in age crop out. Some Mississippian rocks are exposed in Cherokee County in extreme southeastern Kansas. Many of the series in the Paleozoic are absent or only partially developed in Kansas. By the end of the Paleozoic, almost all major groups of life, except the flowering plants and mammals, had developed. The Paleozoic ended in the greatest mass extinction event in world history. During this massive die-off nearly 95% of all marine species went extinct. The Paleozoic Era ended with the largest mass extinction in Earth's history, the Permian–Triassic extinction event. The effects of this catastrophe were so devastating that it took life on land 30 million years into the Mesozoic Era to recover. Recovery of life in the sea may have been much faster. This last 10% of Earth's history is called the Phanerozoic Eon or eon of evident life.. This means that rocks from the Phanerozoic contain fossils, lots of fossils! The Paleozoic period lasted about 325 million years, from about 570 million years ago to about 245 million years ago. So much happened during the Paleozoic that it is divided into seven geologic time periods, shown on the red steps of the Staircase of Time.. This means that rocks from the Phanerozoic contain fossils, lots of fossils! The Paleozoic period lasted about 325 million years, from about 570 million years ago to about 245 million years ago. Many different things happened during each period, but we can only give a summary of them here. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian Period witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. The Devonian | The Carboniferous: Coal Swamps and Glaciers | The Permian | The Great Permian Extinction. Learning Objectives | Terms | Review Questions | Links | References. The Paleozoic era literally translates as the time of ancient life and spans the time period between 544 and 245 million years ago. The Paleozoic is the first of three eras within the Phanerozoic eon (the time of visible life). While life originated during the Archean and increased in complexity during the earlier Proterozoic, the Paleozoic era is marked by the spread of animals with hard preservable parts such as shells and exoskeletons. The great Precambrian expanse of time is divided into the Proterozoic, Archean, and Hadean eons in order of increasing age. The names of the eras in the Phanerozoic eon (the eon of visible life) are the Cenozoic (recent life), Mesozoic (middle life) and Paleozoic (ancient life). The further subdivision of the eras into 12 periods is based on identifiable but less profound changes in life-forms. Neogene Period, Cenozoic Era, Phanerozoic Eon [23 Myr - 1.8 Myr ] In the time scale of Lutgens & Tarbuck, the Neogene Period and the Paleogene Period below are combined and called the Tertiary Period. Calling this span from roughly 66 Myr to 1.8 Myr the Tertiary Period is fairly common in geologic literature. It is sometimes referred to as the age of mammals. Lutgens & Tarbuck further subdivide this Neogene Period into the Miocene Epoch from 23.8 to 5.3 Myr and the Pliocene Epoch from 5.3 to 1.8 Myr.
325 million years, from about 570 million years ago to about 245 million years ago.