"ichthyosaurs, Triassic Omphalosaurus, Triassic plesiosaurs, Jurassic pliosaurs, Late Cretaceous mosasaurs and Cretaceous ptycodontoid sharks. It is also thought that the break-up of Pangaea throughout the Mesozoic brought together previously isolated communities, forcing them to adapt. The increased shelf space caused by sea-level rise and a hyper-greenhouse climate provided more iterations and chances to evolve, resulting in increasing diversity. Another proposal is the evolution of hermit crabs. These exploit the shells of dead gastropods, effectively doubling the life-span of the shell. This allows durophagous predators nearly twice the prey, making it a viable niche to exploit. The net result of the"
"Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic, which is a unit in chronostratigraphy. The Early Triassic is the oldest epoch of the Mesozoic Era and is divided into the Induan and Olenekian ages. The Lower Triassic series is coeval with the Scythian stage, which is today not included in the official timescales but can be found in older literature. In Europe, most of the Lower Triassic"
"is the traditional abbreviation for the Cretaceous Period derived from the German name ""Kreidezeit"", and ""T"" is the abbreviation for the Tertiary Period (a historical term for the period of time now covered by the Paleogene and Neogene periods). The event marks the end of the Mesozoic Era and the beginning of the Cenozoic Era. ""Tertiary"" being no longer recognized as a formal time or rock unit by the International Commission on Stratigraphy, the K-T event is now called the Cretaceous—Paleogene (or K-Pg) extinction event by many researchers. Non-avian dinosaur fossils are only found below the Cretaceous–Paleogene boundary and became"
"during the Triassic, however, one group (Cynodontia) gave rise to the descendant taxon Mammalia, which survived through the Mesozoic to later diversify during the Cenozoic. The Cenozoic era began with the end of the Mesozoic era and the Cretaceous epoch; and continues to this day. The beginning of the Cenozoic was marked by the Cretaceous-Paleogene extinction event during which all non-avian dinosaurs became extinct. The Cenozoic is sometimes called the ""Age of Mammals"". During the Mesozoic, the prototypical mammal was a small nocturnal insectivore something like a tree shrew. Due to their nocturnal habits, most mammals lost their color vision,"
"there were ferns and mosses. Small dinosaurs began to appear like ""Nyasasaurus"" and the ichnogenus ""Iranosauripus"". Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided. It spans the time between Ma and Ma (million years ago). The Middle Triassic is divided into the Anisian and Ladinian ages or stages. Formerly the middle series in the Triassic was also known as Muschelkalk. This name is now only used for a specific unit of rock strata with approximately Middle"
"Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous epoch or Upper Cretaceous series, the Cretaceous period or system, and of the Mesozoic era or erathem. It spanned the interval from . The Maastrichtian was preceded by the Campanian and succeeded by the Danian (part of the Paleogene and Paleocene). At the end of this period, there was a mass extinction known as the Cretaceous–Paleogene extinction event, (formerly known as the Cretaceous–Tertiary extinction event). At this extinction event, many commonly recognized groups such as non-avian dinosaurs, plesiosaurs and mosasaurs, as"
"Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided. It spans the time between Ma and Ma (million years ago). The Middle Triassic is divided into the Anisian and Ladinian ages or stages. Formerly the middle series in the Triassic was also known as Muschelkalk. This name is now only used for a specific unit of rock strata with approximately Middle Triassic age, found in western Europe. During this time there were no flowering plants, but instead"
"the Cretaceous, the late-Paleozoic-to-early-Mesozoic supercontinent of Pangaea completed its tectonic breakup into the present-day continents, although their positions were substantially different at the time. As the Atlantic Ocean widened, the convergent-margin mountain building (orogenies) that had begun during the Jurassic continued in the North American Cordillera, as the Nevadan orogeny was followed by the Sevier and Laramide orogenies. Though Gondwana was still intact in the beginning of the Cretaceous, it broke up as South America, Antarctica and Australia rifted away from Africa (though India and Madagascar remained attached to each other); thus, the South Atlantic and Indian Oceans were newly"
"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"
"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"
"of the Mesozoic era, the continents had rifted into nearly their present form. Laurasia became North America and Eurasia, while Gondwana split into South America, Africa, Australia, Antarctica and the Indian subcontinent, which collided with the Asian plate. This impact gave rise to the Himalayas. The Tethys Sea, which had separated the northern continents from Africa and India, began to close up, forming the Mediterranean sea. The Paleogene (alternatively Palaeogene) Period is a unit of geologic time that began and ended 23.03 Ma and comprises the first part of the Cenozoic Era. This period consists of the Paleocene, Eocene and"
"Mesozoic The Mesozoic Era ( or ) is an interval of geological time from about . It is also called the Age of Reptiles, a phrase introduced by the 19th century paleontologist Gideon Mantell who viewed it as dominated by diapsids such as ""Iguanodon"", ""Megalosaurus"", ""Plesiosaurus"" and ""Pterodactylus"". To paleobotanists, this Era is also called the Age of Conifers. ""Mesozoic"" means ""middle life"", deriving from the Greek prefix ""meso-""/""μεσο-"" for ""between"" and ""zōon""/""ζῷον"" meaning ""animal"" or ""living being"". The name ""Mesozoic"" was proposed in 1840 by the British geologist John Phillips (1800–1874). It is one of three geologic eras of"
"Permian, the Triassic and the early part of the Cretaceous—a span of 200 million years—is missing from the stratigraphic record. The rifting apart of Pangaea formed the Atlantic Ocean as North America shifted into the Northern Hemisphere. Small outcrops from the Cretaceous at the end of the Mesozoic are found in southwest Kentucky, near the state line with Tennessee, in the Jackson Purchase Region and parts of Mississippian Plateau. These sands, clays and gravels deposited at the flooded eastern edge of the Western Interior Seaway and never consolidated into rock. In the Paleogene and Neogene, in the Cenozoic brackish, freshwater"
"Mesoamerican Archaic period The Archaic period, also known as the preceramic period, is a period in Mesoamerican chronology that begins around 8000 BCE and ends around 2000 BCE and is generally divided into Early, Middle, and Late Archaic periods. The period is preceded by the Paleoindian (or Lithic) period and followed by the Preclassic period. Scholars have found it difficult to determine exactly when the Paleoindian period ends and the Archaic begins, but it is generally linked with changing climate associated with the transition from the Pleistocene to the Holocene epochs, and absence of extinct Pleistocene animals. It is also"
"ammonites and rudists, while dinosaurs continued to dominate on land. During this time, new groups of mammals and birds, as well as flowering plants, appeared. The Cretaceous (along with the Mesozoic) ended with the Cretaceous–Paleogene extinction event, a large mass extinction in which many groups, including non-avian dinosaurs, pterosaurs and large marine reptiles died out. The end of the Cretaceous is defined by the abrupt Cretaceous–Paleogene boundary (K–Pg boundary), a geologic signature associated with the mass extinction which lies between the Mesozoic and Cenozoic eras. The Cretaceous as a separate period was first defined by Belgian geologist Jean d'Omalius d'Halloy"
"Mesolithic In Old World archaeology, Mesolithic (Greek: μέσος, ""mesos"" ""middle""; λίθος, ""lithos"" ""stone"") is the period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic is often used synonymously, especially for outside northern Europe, and for the corresponding period in the Levant and Caucasus. The Mesolithic has different time spans in different parts of Eurasia. It refers to the final period of hunter-gatherer cultures in Europe and Western Asia, between the end of the Last Glacial Maximum and the Neolithic Revolution. In Europe it spans roughly ~12,500 to 5,000 BP; in Southwest Asia (the Epipalaeolithic Near East) roughly 22,000"
"Period of the Mesozoic Era, with the opening of the Tethys Ocean, between the Eurasian and African tectonic plates, between about 240 MBP and 220 MBP (million years before present). The present Mediterranean Sea descends from this somewhat larger Tethys sea. At about 180 MBP, in the Jurassic Period, the two plates reversed direction and began to compress the Tethys floor, causing it to be subducted under Eurasia and pushing up the edge of the latter plate in the Alpine Orogeny of the Oligocene and Miocene Periods. Several microplates were caught in the squeeze and rotated or were pushed laterally,"
"three to occur during the duration of the triassic mass extinction. This stage developed about 217 to 204 million years ago. This stage comes after the Carnian stage, and is known for its rising populations of mesozoic organisms as well as the decline in populations of previous species that had once played important roles in the environment. This stage identifies with its own species of ammonoid index fossils, which is how it differs from the preceding Carnian stage. In this stage, fossils and evidence of ""Cyrtopleurites bicrenatus"" are found in these different areas of the world, which seem to be"
"much of Permian and Triassic period (280 - 195 Ma), while changing sea levels added a thick limestone covering, with only the tops of the Cévennes protruding as islands in the Jurassic sea. This in turn was eroded, The Cévennes forms the watershed between the Atlantic and Mediterranean. In late Cretaceous and early Tertiary times further mountain building occurred. The Alpine orogeny lifted and deformed the Alps and the Pyrenees though the Massif Central acted as a rigid block, and the cover rocks remained mostly horizontal. Some have been folded through later faulting at the time of the opening of"
"end of the Cretaceous allowed for the expansion of mammals, which had evolved from the therapsids, a group of synapsid amniotes, during the late Triassic Period. The Cenozoic world has seen great diversification of bony fishes, frogs, birds and mammals. Over half of all living vertebrate species (about 32,000 species) are fish (non-tetrapod craniates), a diverse set of lineages that inhabit all the world's aquatic ecosystems, from snow minnows (Cypriniformes) in Himalayan lakes at elevations over to flatfishes (order Pleuronectiformes) in the Challenger Deep, the deepest ocean trench at about . Fishes of myriad varieties are the main predators in"
"Paleozoic The Paleozoic (or Palaeozoic) Era (; from the Greek ""palaios"" (παλαιός), ""old"" and ""zoe"" (ζωή), ""life"", meaning ""ancient life"") is the earliest of three geologic eras of the Phanerozoic Eon. It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification"
"recent descendants. Psocoptera was first appeared in the Permian period, they are often regarded as the most primitive of the hemipteroids. The Triassic () was a period when arid and semiarid savannas developed and when the first mammals, dinosaurs, and pterosaurs also appeared. During the Triassic, almost all the Earth's land mass was still concentrated into Pangaea. From the east a vast gulf entered Pangaea, the Tethys sea. The remaining shores were surrounded by the world-ocean known as Panthalassa. The supercontinent Pangaea was rifting during the Triassic—especially late in the period—but had not yet separated. The climate of the Triassic"
"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"
"that hybodonts flourished at that time. A shift in hybodonts was seen during the Middle Jurassic, a transition between the distinctly different assemblages seen in the Triassic – Early Jurassic and the Late Jurassic – Cretaceous. As neoselachians (group of modern sharks) diversified further during the Late Jurassic, hybodontiforms became less prevalent in open marine conditions but remained diverse in fluvial and restricted settings during the Cretaceous. By the Cretaceous, hybodontiforms were primarily (though not solely) restricted to freshwater settings. They remained successful during the Cretaceous by adapting to freshwater conditions, for example seven genera were found in freshwater deposits"
"mid-Triassic 4M to 6M years after the extinction, and not fully proliferated until 30M years after the extinction. Animal life was then dominated by various archosaurs: dinosaurs, pterosaurs, and aquatic reptiles such as ichthyosaurs, plesiosaurs, and mosasaurs. The climatic changes of the late Jurassic and Cretaceous favored further adaptive radiation. The Jurassic was the height of archosaur diversity, and the first birds and eutherian mammals also appeared. Some have argued that insects diversified in symbiosis with angiosperms, because insect anatomy, especially the mouth parts, seems particularly well-suited for flowering plants. However, all major insect mouth parts preceded angiosperms, and insect"
"metamorphism in the Late Eocene (40–30 Ma), presumably due to the collision between the continents of India and Eurasia. Sedimentary strata from the Palaeozoic are mainly Carboniferous sandstone, metasandstone, shale and phyllite, and lesser Ordovician, Silurian and Permian limestone. Precambrian strata are rarely exposed. Rocks from the Triassic include inter-bedded limestone and basaltic volcanic units, most common along the terrane's southern margin. In the northern terrane the Jurassic strata are deepwater sandstone and shale, often with ophiolitic assemblages. In the southern terrane the Jurassic strata are marine limestone and mudstone. Strata from the Lower Cretaceous are clastic mudstone, sandstone and"
"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"
"of Pangaea into Laurasia and Gondwana in an extinction known as the Jurassic-Cretaceous extinction. Sea levels rose, destroying fern prairies and creating shallows. Ichthyosaurs became extinct whereas sauropods, as a whole, did not; in fact, some species, like ""Titanosaurus"", lived until the K-T extinction. The increase in sea-levels opened up the Atlantic sea way which would continue to get larger over time. The divided world would give opportunity for the diversification of new dinosaurs. The Cretaceous is the longest period in the Mesozoic, spans from 145 million to 66 million years ago, and is divided into two epochs: Early Cretaceous,"
"Cretaceous. Cidaroids also are thought to have contributed to the downfall of the crinoids. Mesozoic marine revolution The Mesozoic Marine Revolution (MMR) is the rapid adaption to shell-crushing (durophagous) and boring predation in benthic organisms throughout the Mesozoic era (251 Mya to 66 Mya). The term was first coined by Geerat J. Vermeij, who based his work on that of Steven M. Stanley. While initially restricted to the Late Cretaceous (145 Mya to 66 Mya), more recent studies have suggested that the beginning of this ecological arms race extends back into the Norian (Late Triassic) It is the important transition"
"Lastly at the end of the Triassic and the beginning of the Jurassic was the first appearance of small shrew like mammals that came from reptiles. The main characteristic of Pangea’s climate is that its position on Earth was advantageous for starting a cycle of megamonsoonal circulation. The monsoons reached their maximum strength in the Triassic period of the Mesozoic. During the late Carboniferous, there was peat formation in what is currently Europe and the Eastern areas of North America. The wetter, swamp like conditions needed to form peat were contrasted with the dry conditions on the Colorado Plateau. Nearing"
"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"
"Caledonians slowly phase into the Variscan orogeny. The break up of Pangea occurs during the Kimmerian tectonic phase for most of the Mesozoic, until the early-mid Cretaceous, this marks the start of creating the present position of our continents today. During the Jurassic, rifting activity reaches its maximum and North America starts to move apart from Eurasia following that event in the Cretaceous the southern part of North America starts to open up the Atlantic Ocean with the separation of South America and Africa. At the end of the Mesozoic the North Sea reached its final position where it lies"
"diversification actually slowed when they arrived, so their anatomy originally must have been suited for some other purpose. Mesozoic The Mesozoic Era ( or ) is an interval of geological time from about . It is also called the Age of Reptiles, a phrase introduced by the 19th century paleontologist Gideon Mantell who viewed it as dominated by diapsids such as ""Iguanodon"", ""Megalosaurus"", ""Plesiosaurus"" and ""Pterodactylus"". To paleobotanists, this Era is also called the Age of Conifers. ""Mesozoic"" means ""middle life"", deriving from the Greek prefix ""meso-""/""μεσο-"" for ""between"" and ""zōon""/""ζῷον"" meaning ""animal"" or ""living being"". The name ""Mesozoic"" was"