"the late Paleozoic. The Mesozoic (""middle life"") era lasted from 251 Ma to Ma. It is subdivided into the Triassic, Jurassic, and Cretaceous periods. The era began with the Permian–Triassic extinction event, the most severe extinction event in the fossil record; 95% of the species on Earth died out. It ended with the Cretaceous–Paleogene extinction event that wiped out the dinosaurs.. The Cenozoic (""new life"") era began at Ma, and is subdivided into the Paleogene, Neogene, and Quaternary periods. These three periods are further split into seven sub-divisions, with the Paleogene composed of The Paleocene, Eocene, and Oligocene, the Neogene"
"by an asteroid impactor that created Chicxulub Crater on the Yucatán Peninsula. Towards the Late Cretaceous, large volcanic eruptions are also believed to have contributed to the Cretaceous–Paleogene extinction event. Approximately 50% of all genera became extinct, including all of the non-avian dinosaurs. The Triassic ranges roughly from 252 million to 201 million years ago, preceding the Jurassic Period. The period is bracketed between the Permian–Triassic extinction event and the Triassic–Jurassic extinction event, two of the ""big five"", and it is divided into three major epochs: Early, Middle, and Late Triassic. The Early Triassic, about 252 to 247 million years"
"Jurassic period is divided into three epochs: Early, Middle, and Late. Similarly, in stratigraphy, the Jurassic is divided into the Lower Jurassic, Middle Jurassic, and Upper Jurassic series of rock formations. The Jurassic is named after the Jura Mountains within the European Alps, where limestone strata from the period were first identified. By the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses: Laurasia to the north, and Gondwana to the south. This created more coastlines and shifted the continental climate from dry to humid, and many of the arid deserts of the Triassic were replaced"
"ago and features 3 major epochs: The Early Jurassic, the Middle Jurassic, and the Late Jurassic. The Early Jurassic spans from 200 to 175 million years ago. The climate was tropical, much more humid than the Triassic. In the oceans, plesiosaurs, ichthyosaurs and ammonites were abundant. On land, dinosaurs and other archosaurs staked their claim as the dominant race, with theropods such as ""Dilophosaurus"" at the top of the food chain. The first true crocodiles evolved, pushing the large amphibians to near extinction. All-in-all, archosaurs rose to rule the world. Meanwhile, the first true mammals evolved, remaining relatively small but"
"died out at the end of the Triassic. But in the undergrowth were various types of early mammals, as well as tritylodont mammal-like reptiles, lizard-like sphenodonts, and early lissamphibians. Early Jurassic The Early Jurassic epoch (in chronostratigraphy corresponding to the Lower Jurassic series) is the earliest of three epochs of the Jurassic period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma (million years ago), and ends at the start of the Middle Jurassic 174.1 Ma. Certain rocks of marine origin of this age in Europe are called ""Lias"" and that name was used for the period,"
"are thought to have been shrub to small-tree sized. Ginkgo plants were particularly common in the mid- to high northern latitudes. In the Southern Hemisphere, podocarps were especially successful, while Ginkgos and Czekanowskiales were rare. In the oceans, modern coralline algae appeared for the first time. However, they were a part of another major extinction that happened within the next major time period. Jurassic The Jurassic (; from Jura Mountains) was a geologic period and system that spanned 56 million years from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period Mya."
"during the Jurassic Period around 180 million years ago. The first event was the separation of the western half of Gondwana, which includes Africa and South America, from the eastern half, which includes Antarctica, Australia, Madagascar, and India. Next, 40 million years later, South America and Africa began to split which began to open up the Atlantic Ocean. Also around this time India and Madagascar began to detach from Australia and Antarctica, this separation created the Indian Ocean. Lastly in the Cretaceous India and Madagascar began to split and Australia and Antarctica began to detach from one another. The life"
"Jurassic, Middle Jurassic, and Late Jurassic. The Early Jurassic Epoch spans from 200 million to 175 million years ago. The climate was much more humid than the Triassic, and as a result, the world was very tropical. In the oceans, plesiosaurs, ichthyosaurs and ammonites dominated the seas. On land, dinosaurs and other reptiles dominated the land, with species such as ""Dilophosaurus"" at the apex. The first true crocodiles evolved, pushing the large amphibians to near extinction. The reptiles rose to rule the world. Meanwhile, the first true mammals evolved, but never exceeded the height of a shrew. The Middle Jurassic"
"Late Triassic The Late Triassic is the third and final of three epochs of the Triassic Period in the geologic timescale. The Triassic-Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. The corresponding series is known as the Upper Triassic. In Europe the epoch was called the Keuper, after a German lithostratigraphic group (a sequence of rock strata) that has a roughly corresponding age. The Late Triassic spans the time between Ma and Ma (million years ago). The Late Triassic is divided into the Carnian, Norian and Rhaetian ages."
"the epochs were renamed and redefined. Tertiary Tertiary is the former term for the geologic period from 66 million to 2.58 million years ago, a timespan that occurs between the superseded Secondary period and the Quaternary. The Tertiary is no longer recognized as a formal unit by the International Commission on Stratigraphy, but the word is still widely used. The traditional span of the Tertiary has been divided between the Paleogene and Neogene periods and extends to the first stage of the Pleistocene Epoch, the Gelasian stage. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene"
"a boom of reptilian evolution on land as the first true dinosaurs evolved, as well as pterosaurs. By the end of the period the first gigantic dinosaurs had evolved and advanced pterosaurs colonised Pangaea's deserts. The climactic change, however, resulted in a large die-out known as the Triassic-Jurassic extinction event, in which all archosaurs (excluding ancient crocodiles), synapsids, and almost all large amphibians became extinct, as well as 34% of marine life in the fourth mass extinction event. The extinction's cause is debated. The Jurassic ranges from 200 million to 145 million years ago, and features three major epochs: Early"
"as the first true dinosaurs evolved, as well as pterosaurs. During the Late Triassic, some advanced cynodonts gave rise to the first Mammaliaformes. All this climatic change, however, resulted in a large die-out known as the Triassic-Jurassic extinction event, in which many archosaurs (excluding pterosaurs, dinosaurs and crocodylomorphs), most synapsids, and almost all large amphibians became extinct, as well as 34% of marine life, in the Earth's fourth mass extinction event. The cause is debatable;flood basalt eruptions at the Central Atlantic magmatic province is cited as one possible cause. The Jurassic ranges from 200 million years to 145 million years"
"Triassic–Jurassic extinction event The Triassic–Jurassic extinction event marks the boundary between the Triassic and Jurassic periods, , and is one of the major extinction events of the Phanerozoic eon, profoundly affecting life on land and in the oceans. In the seas, a whole class (conodonts) and 23-34% of marine genera disappeared. On land, all archosaurs other than crocodylomorphs (Sphenosuchia and Crocodyliformes) and Avemetatarsalia (pterosaurs and dinosaurs), some remaining therapsids, and many of the large amphibians became extinct. About 42% of all terrestrial tetrapods went extinct. This event vacated terrestrial ecological niches, allowing the dinosaurs to assume the dominant roles in"
"Early Jurassic The Early Jurassic epoch (in chronostratigraphy corresponding to the Lower Jurassic series) is the earliest of three epochs of the Jurassic period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma (million years ago), and ends at the start of the Middle Jurassic 174.1 Ma. Certain rocks of marine origin of this age in Europe are called ""Lias"" and that name was used for the period, as well, in 19th-century geology. In southern Germany rocks of this age are called Black Jurassic. There are two possible origins for the name Lias: the first reason is"
"Jurassic (208-146 million years ago) when a discontinuous reef system 7,000 km long stretched across the northern Tethys and North Atlantic basins. This chain of sponge reefs is the largest known biostructure to have ever existed on Earth. The sponge reefs declined throughout the Cretaceous period as coral and rudist reefs were becoming prominent. It is theorized that the spread of diatoms may have been detrimental to the sponges, as diatoms compete with hexactinellid sponges for silica. It is estimated through radiocarbon dating of reef cores that the reefs have been living on the continental shelf of Western Canada for"
"epochs: Early, Middle, and Late. Similarly, in stratigraphy, the Jurassic is divided into the Lower Jurassic, Middle Jurassic, and Upper Jurassic series of rock formations, also known as ""Lias"", ""Dogger"" and ""Malm"" in Europe. The separation of the term Jurassic into three sections originated with Leopold von Buch. The faunal stages from youngest to oldest are: During the early Jurassic period, the supercontinent Pangaea broke up into the northern supercontinent Laurasia and the southern supercontinent Gondwana; the Gulf of Mexico opened in the new rift between North America and what is now Mexico's Yucatan Peninsula. The Jurassic North Atlantic Ocean"
"by many new predators such as ""Allosaurus"". Conifer forests made up a large portion of the forests. In the oceans, plesiosaurs were quite common, and ichthyosaurs flourished. This epoch was the peak of the reptiles. The Late Jurassic spans from 163 to 145 million years ago. During this epoch, the first avialans, like ""Archaeopteryx"", evolved from small coelurosaurian dinosaurs. The increase in sea levels opened up the Atlantic seaway, which has grown continually larger until today. The divided landmasses gave opportunity for the diversification of new dinosaurs. The Cretaceous is the longest period of the Mesozoic, but has only two"
"Rhaetian The Rhaetian is, in geochronology, the latest age of the Triassic period or in chronostratigraphy the uppermost stage of the Triassic system. It lasted from to million years ago. It was preceded by the Norian and succeeded by the Hettangian (the lowermost stage or earliest age of the Jurassic). In this age, Pangaea began to break up, though the Atlantic Ocean was not yet formed. The Rhaetian is named after the Rhaetian Alps, a mountain chain stretching over parts of eastern Switzerland, northern Italy and western Austria. The stage was introduced in scientific literature by Austrian geologist Eduard Suess"
"northern plains of the United States and Canada during the late Jurassic, most exposed sediments from this period are continental, such as the alluvial deposits of the Morrison Formation. The first of several massive batholiths were emplaced in the northern Cordillera beginning in the mid-Jurassic, marking the Nevadan orogeny. Important Jurassic exposures are also found in Russia, India, South America, Japan, Australasia and the United Kingdom. The Cretaceous Period extends from circa to . During the Cretaceous, the late Paleozoic-early Mesozoic supercontinent of Pangaea completed its breakup into present day continents, although their positions were substantially different at the time."
"the Paleozoic, Mesozoic and Cenozoic, which are divided by major mass extinctions. 542 Ma – 251.0 Ma and contains the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian periods. From 251.4 Ma to 66 Ma and containing the Triassic, Jurassic and Cretaceous periods. 66 Ma – present Timeline of the evolutionary history of life This timeline of the evolutionary history of life represents the current scientific theory outlining the major events during the development of life on planet Earth. In biology, evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity"
"Tertiary Tertiary is the former term for the geologic period from 66 million to 2.58 million years ago, a timespan that occurs between the superseded Secondary period and the Quaternary. The Tertiary is no longer recognized as a formal unit by the International Commission on Stratigraphy, but the word is still widely used. The traditional span of the Tertiary has been divided between the Paleogene and Neogene periods and extends to the first stage of the Pleistocene Epoch, the Gelasian stage. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start of"
"known from the Jurassic, to be more precise between 227 and 121 Ma. The Cretaceous sauropods form two groups. The Diplodocoidea lived from 121 to 66 Ma. The Titanosauriformes lived from 132 to 66 Ma. The latter clade consists of series of nested subgroups, the Titanosauria, the Titanosauridae and Saltasauridae. Both the Diplodocoidea and Titanosauriformes are descended from the Neosauropoda, the earliest of which lived in about 169 Ma. The sauropods are famous for being the largest land animals that ever lived, and for having relatively small skulls. The enlargement of prosauropod and sauropod dinosaurs into these giants and the"
"the Triassic period, the French region of Provence subsided and was covered by the sea, leaving thick layers of various limestone deposits. Several million years later, with the arrival of the Jurassic period, the area was covered by a warm shallow sea, which allowed the growth of various Corals. The Cretaceous period saw what is now Basse Provence being raised and the sea reaching the current location of the Alps, which were themselves erected during the tertiary era. As a result of the large-scale geological activity, many of the Jurassic limestone deposits fractured, forming relief with valleys and other such"
"Paleogene The Paleogene (; also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago (Mya) to the beginning of the Neogene Period Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon. The Paleogene is most notable for being the time during which mammals diversified from relatively small, simple forms into a large group of diverse animals in the wake of the Cretaceous–Paleogene extinction event that ended the preceding Cretaceous Period. This period consists"
"Following the Paleozoic, the Mesozoic extended roughly 186 million years, from when the Cenozoic Era began. This time frame is separated into three geologic periods. From oldest to youngest: The lower boundary of the Mesozoic is set by the Permian–Triassic extinction event, during which approximately 90% to 96% of marine species and 70% of terrestrial vertebrates became extinct. It is also known as the ""Great Dying"" because it is considered the largest mass extinction in the Earth's history. The upper boundary of the Mesozoic is set at the Cretaceous–Paleogene extinction event (or K–Pg extinction event), which may have been caused"
"Late Jurassic The Late Jurassic is the third epoch of the Jurassic period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata. In European lithostratigraphy, the name ""malm"" indicates rocks of Late Jurassic age. In the past, this name was also used to indicate the unit of geological time, but this usage is now discouraged to make a clear distinction between lithostratigraphic and geochronologic/chronostratigraphic units. The Late Jurassic is divided into three ages, which correspond with the three (faunal) stages of Upper Jurassic rock:"
"Earth of the Varangian glaciation. The Phanerozoic Eon is the current eon in the geologic timescale. It covers roughly 541 million years. During this period continents drifted about, eventually collected into a single landmass known as Pangea and then split up into the current continental landmasses. The Phanerozoic is divided into three eras – the Paleozoic, the Mesozoic and the Cenozoic. Most of biological evolution occurred during this time period. The Paleozoic spanned from roughly (Ma) and is subdivided into six geologic periods; from oldest to youngest they are the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian. Geologically, the Paleozoic"
"Epoch spans from 100 million to 65 million years ago. The Late Cretaceous featured a cooling trend that would continue into the Cenozoic Era. Eventually, tropical ecology was restricted to the equator and areas beyond the tropic lines featured extreme seasonal changes of weather. Dinosaurs still thrived as new species such as ""Tyrannosaurus"", ""Ankylosaurus"", ""Triceratops"" and Hadrosaurs dominated the food web. Whether or not Pterosaurs went into a decline as birds radiated is debated, however many families survived until the end of the Cretaceous, alongside new species such as the gigantic ""Quetzalcoatlus"". Marsupials evolved within the large conifer forests as"
"Jura Mountains. A series of tectonic events in the Triassic, Jurassic and Cretaceous periods caused different paleogeographic regions. The Alps are subdivided by different lithology (rock composition) and nappe structure according to the orogenic events that affected them. The geological subdivision differentiates the Western, Eastern Alps and Southern Alps: the Helveticum in the north, the Penninicum and Austroalpine system in the centre and, south of the Periadriatic Seam, the Southern Alpine system. According to geologist Stefan Schmid, because the Western Alps underwent a metamorphic event in the Cenozoic Era while the Austroalpine peaks underwent an event in the Cretaceous Period,"
"zone. The Triassic saw active crustal stretching via the rifting process, lower sea levels and volcanic activity. As the Jurassic (200–145 Ma) started, Pangaea began to break up into two continents, Gondwana and Laurasia. At this time sea levels rose. The burial of algae and bacteria below the mud of the sea floor during this time resulted in the formation of North Sea oil and natural gas, much of it trapped in overlying sandstone by deposits formed as the seas fell to form the swamps and salty lakes and lagoons that were home to dinosaurs. Volcanism and a rift system"
"Epoch spans from 175 million to 163 million years ago. During this epoch, dinosaurs flourished as huge herds of sauropods, such as ""Brachiosaurus"" and ""Diplodocus"", filled the fern prairies of the Middle Jurassic. Many other predators rose as well, such as ""Allosaurus"". Conifer forests made up a large portion of the world's forests. In the oceans, plesiosaurs were quite common, and ichthyosaurs were flourishing. This epoch was the peak of the reptiles. The Late Jurassic Epoch spans from 163 million to 145 million years ago. The Late Jurassic featured a massive extinction of sauropods and ichthyosaurs due to the separation"
"Pleistocene The Pleistocene (, often colloquially referred to as the Ice Age) is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the world's most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era. In the ICS timescale, the Pleistocene is divided into four stages or ages, the Gelasian, Calabrian, Middle Pleistocene (unofficially the 'Chibanian') and Upper"
"stages were characterized by: The [[Permian–Triassic extinction event]] about 252 million years ago, which was a prolonged event due to the accumulation of several extinction pulses, ended the dominance of carnivorous therapsids. In the early Triassic, most medium to large land carnivore niches were taken over by [[archosaur]]s which, over an extended period (35 million years), came to include the [[Crocodylomorpha|crocodylomorphs]], the [[pterosaur]]s and the dinosaurs; however, large cynodonts like ""[[Trucidocynodon]]"" and [[Traversodontidae|traversodontids]] still occupied large sized carnivorous and herbivorous niches respectively. By the Jurassic, the dinosaurs had come to dominate the large terrestrial herbivore niches as well. The first"