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Big bang Theory
The big bang theory is the theory when its prevailing cosmological model that describes the early development of the universe. It occurred approximately 13.75 billion years ago. The universe was once in an extremely hot and dense state that expanded rapidly. Thie rapid expansion caused the universe to cool and resulted in its present state of expansion. -
Birth of the Earth
About four and one half billion years ago our protosun was slowly collapsing under the force of its gravity. As it did this, due to the immense compression caused by gravity it became extremely hot. Millions of degrees centigrade. The more compact it got, the hotter it got. It was not alone in the sky, it was part of a community of stars and protostars that lay in the outer regions of our galaxy, the Milky Way. -
Precambrian Time
The Precambrian Era spans from the formation of Earth about 4570 Ma (million years) ago to the beginning of the Cambrian Period, about 541.0 ± 1.0 Ma. During this period macroscopic hard-shelled animals first appeared in abundance. The Precambrian Era is the earliest geologic age which are marked by layers of sedimentary rock. -
Paleozoic Era
The Paleozoic Era is the first of three geologic eras and lasted about 325 million years, from about 570 million years ago to about 245 million years ago. It consisted of six major periods. -
Cambrian Period
The Cambrian Era is the first geologic period of the pelozoic era lasting from 541.0-1.0 to 485.4 1.9 million years ago. It is succeeded by the Ordovician.The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's Cambrian rocks are best exposed. -
Ordovician Period
it is a geologic period and system, the second of six of the Paleozoic Era. It covers the time between 485.4-1.9 to 443.4-1.5 million years ago. It follows the cambrian period and is followed by the silurian period. -
Silurian Period
The Silurian (443.7 to 416.0 million years ago) was a time when the Earth underwent changes that was very important for the environment and life within it. Large glacial formations melte and caused a large rise in levels of the major seas. Coral reefs made their first appearance. -
Devonian Period
The Devonian Period lasted from 417 million years ago to 354 million years ago. It is named for Devon, England where the old red sandstone of the Devonian was first studied. It is the age of fish. -
Mississippian Period
The Mississippian is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earliest/lowermost of two subperiods of the Carboniferous period and lasted from roughly 358.9 ± 0.4 to 323.2 ± 0.4 million years ago.
The rock beds that define the Mississippian are well identified. -
Pennsylvanian Period
It is the younger of two subperiods of the Carboniferous Period. It lasted from roughly 323.2 ± 1.3 to 298.9 ± 0.8 Ma (million years ago). The rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain by a few million years. -
Permian Period
Permianis the geologic period and system which extends fron 298.9-0.2 to 252.2 million years ago. It is the last period of the Paleozoic Era fand follows the Carboniferous Period of the Mesozoic Era. -
Mesozoic Era
The “Age of Dinosaurs” is the Mesozoic Era. It is divided into three periods: the Triassic (245-208 million years ago), Jurassic (208-145 million years ago), and Cretaceous (145-66 million years ago). -
Triassic Period
Triassic is a geologic period and system that extends from about 250 to 200 ma and is the first period of the Mesozoic era,and lies between the Permian and Jurassic periods. -
Jurassic Period
The Jurassic Period is a geologic period and system that extends from 201.3-0.6 million years ago to 145-4 ma. Dinosaurs dominated the land and land plants were abundant. -
Cretaceous Period
The Cretaceous is usually noted is 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. -
Cenozoic Era
The last and most recent of the geologic periods.The Age of Mammals. It is also the period of flowering plants, the insects, the newest fish (teleostei) and modern birds. -
Eocene Epoch
Eocene Epoch is the econd of three major worldwide divisions of the Paleogene Period (65.5 million to 23 million years ago) that began 55.8 million years ago and ended 33.9 million years ago. It began the appearance of many modern groups of organisms, especially mammals and mollusks. -
Oligocene Epoch
The third and last major worldwide division of the Paleogene Period, that took place between 33.9 million to 23 million years ago. The Oligocene Epoch is subdivided into two ages and their corresponding rock stages: the Rupelian and the Chattian. sparseness of the number of modern animals that originated during that time. The number of modern animals that originated during this time were sparse.
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Paleocene Epoch
The Paleocene epoch began 65 million years ago and ended 54.8 million years ago. It was a time of dense forests. The extinction of the dinosaurs and other giant reptiles at the end of the Cretaceous allowed for mammals and birds and so many new creatures appeared. -
Miocene Epoch
A geologic epoch of the neogene period and extends from about 23.03 to 5.332 million years ago. Itwas a time of warmer global climates and kelp forests and grasslands made their first appearances. -
Pliocene Epoch
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. it is the second and youngest epoch of the Neogene period in the Cenozoic era. -
Pleistocene Epoch
It is the geologic epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the worlds recent period of repeating glaciations. -
Holocene Epoch
It is a geologic epoch which began at the end of the Pleistocene and continues to the present. The holocene is part of the quaterny period. Its name comes from the greek words holos for whole or entire. During the Holocene epoch, the earth's surface to its present form was completed.
