The Jurassic is a geologic period and system The geologic time scale is a chronologic schema relating stratigraphy to time that is used by geologists, paleontologists and other earth scientists to describe the timing and relationships between events that have occurred during the history of the Earth. The table of geologic time spans presented here agrees with the dates and nomenclature that extends from about 199.6± 0.6 Ma Annum is one form of the Latin noun meaning year, not a form normally used for derivatives in modern languages: the accusative singular of the second declension masculine noun annus , anni (genitive singular and nominative plural) (million years ago) to 145.5± 4 Ma, that is, from the end of the Triassic The Triassic is a geologic period and system that extends from about 251 to 199 Ma . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events. The extinction event that closed the Triassic period has recently been more to the beginning of the Cretaceous The Cretaceous , usually abbreviated K for its German translation Kreide, is a geologic period and system from circa 145.5 ± 4 to 65.5 ± 0.3 million years ago (Ma). In the geologic timescale, the Cretaceous follows on the Jurassic period and is followed by the Paleogene period. It is the youngest period of the Mesozoic era, and at 80 million. The Jurassic constitutes the middle period of the Mesozoic The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. The division of time into eras dates back to Giovanni Arduino, in the 18th century, although his original name for the era now called the "Mesozoic" was "Secondary" . Lying between the Paleozoic and the Cenozoic, "Mesozoic" means "middle era, also known as the "Age of Reptiles". The start of the period is marked by the major Triassic–Jurassic extinction event. However the end of the Jurassic Period did not witness any major extinction event. The start and end of the period are defined by carefully selected locations; the uncertainty in dating arises from trying to date these horizons.
The chronostratigraphic term Jurassic is directly linked to the Swiss Jura Mountains The Jura Mountains are a small mountain range located north of the Alps, separating the Rhine and Rhone rivers and forming part of the watershed of each. The mountain range sensu Johann Gottfried Ebel is located in France, Switzerland, and Germany. The name “Jura” is derived from the Celtic root "jor" which was latinised into ". Alexander von Humboldt Friedrich Wilhelm Heinrich Alexander Freiherr von Humboldt (September 14, 1769 – May 6, 1859) was a German naturalist and explorer, and the younger brother of the Prussian minister, philosopher, and linguist, Wilhelm von Humboldt (1767-1835). Humboldt's quantitative work on botanical geography was foundational to the field of biogeography (*1769, † 1859) recognised the mainly limestone Limestone is a sedimentary rock composed largely of the mineral calcite . The deposition of limestone strata is often a by-product and indicator of biological activity in the geologic record. Calcium (along with nitrogen, phosphorus, and potassium) is a key mineral to plant nutrition: soils overlying limestone bedrock tend to be pre-fertilized dominated mountain range of the Swiss Jura Mountains The Jura Mountains are a small mountain range located north of the Alps, separating the Rhine and Rhone rivers and forming part of the watershed of each. The mountain range sensu Johann Gottfried Ebel is located in France, Switzerland, and Germany. The name “Jura” is derived from the Celtic root "jor" which was latinised into " as a separate formation that was not at the time included in the established stratigraphic system defined by Abraham Gottlob Werner Abraham Gottlob Werner , was a German geologist who set out a now obsolete theory about the stratification of the Earth's crust and coined the now obsolete word Neptunism (* 1749, † 1817) and named it “Jurakalk” in 1795.[4][5][6] The name “Jura” is derived from the celtic root “jor” which was latinised into “juria”, meaning forest (i.e. “Jura” is forest mountains).[4][5][7]
Contents |
Divisions
Key events in the Jurassic -200 — – -195 — – -190 — – -185 — – -180 — – -175 — – -170 — – -165 — – -160 — – -155 — – -150 — – -145 — – Cretaceous The Cretaceous , usually abbreviated K for its German translation Kreide, is a geologic period and system from circa 145.5 ± 4 to 65.5 ± 0.3 million years ago (Ma). In the geologic timescale, the Cretaceous follows on the Jurassic period and is followed by the Paleogene period. It is the youngest period of the Mesozoic era, and at 80 million Triassic The Triassic is a geologic period and system that extends from about 251 to 199 Ma . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events. The extinction event that closed the Triassic period has recently been more Jurassic Hettangian Sinemurian Pliensbachian Toarcian Aalenian Bajocian Bathonian Callovian The Callovian is a stage on the geologic time scale occurring 164.7 ± 4.0 Ma to 161.2 ± 4.0 Ma . It is the last stage of the Middle Jurassic Oxfordian Kimmeridgian Tithonian The Tithonian is the final stage of the Late Jurassic Epoch. It spans the time between 150.8 ± 4 Ma and 145.5 ± 4 Ma . It is followed by the Berriasian stage of the Early Cretaceous Epoch J u r a s s i c Mesozoic The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. The division of time into eras dates back to Giovanni Arduino, in the 18th century, although his original name for the era now called the "Mesozoic" was "Secondary" . Lying between the Paleozoic and the Cenozoic, "Mesozoic" means "middle An approximate timescale of key Jurassic events. Axis scale: millions of years ago.The Jurassic period of time is usually broken into Early The Early Jurassic epoch (in chronostratigraphy corresponding to the Lower Jurassic series, originally the "Lias") is the earliest of three epochs of the Jurassic period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event (199.6 Ma (million years ago)) and ends at the start of the Middle Jurassic (175.6 Ma), Middle, and Late Jurassic Pangaea broke up into two supercontinents, Laurasia to the north, and Gondwana to the south. The result of this break-up was the spawning of the Atlantic Ocean. However, at this time, the Atlantic Ocean was relatively narrow subdivisions, also known as Lias, Dogger and Malm in Europe.[8] The corresponding terms for the rocks are Lower, Middle, and Upper Jurassic. The separation of the term Jurassic into three sections goes back to Leopold von Buch (* 1774, † 1853).[6] The faunal stages In chronostratigraphy, a stage is a succession of rock strata laid down in an single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries from youngest to oldest are:
Paleogeography and tectonics
Jurassic limestones and marls (the Matmor Formation) in southern Israel Israel officially the State of Israel ( מְדִינַת יִשְׂרָאֵל (help·info), Medinat Yisra'el; Arabic: دَوْلَةُ إِسْرَائِيلَ, Dawlat Isrā'īl), is a country in Western Asia located on the eastern shore of the Mediterranean Sea. It borders Lebanon in the north, Syria in the northeast, Jordan in the east, and.During the early Jurassic period, the supercontinent In geology, a supercontinent is a landmass comprising more than one continental core, or craton. The assembly of cratons and accreted terranes that form Eurasia qualifies as a supercontinent today Pangaea The name was first used by the German originator of the continental drift theory, Alfred Wegener, in the 1920 edition of his book The Origin of Continents and Oceans , in which a postulated supercontinent Pangaea played a key role broke up into the northern supercontinent Laurasia Laurasia was a supercontinent that most recently existed as a part of the split of the Pangaean supercontinent in the late Mesozoic era. It included most of the landmasses which make up today's continents of the northern hemisphere, chiefly Laurentia (the name given to the North American craton), Baltica, Siberia, Kazakhstania, and the North China and the southern supercontinent Gondwana Gondwana , originally Gondwanaland, is the name given to a southern precursor-supercontinent (final ongoing joining occurred between ca. 570-510 Ma, joining East Gondwana to West Gondwana) and then as a remnant separated from Laurasia 180-200 million years ago during the breakup of the Pangaea supercontinent that existed about 500 to 200 Ma ago; the Gulf of Mexico The Gulf of Mexico is the ninth largest body of water in the world. Considered a smaller part of the Atlantic Ocean, it is an ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on opened in the new rift between North America and what is now Mexico's Yucatan Peninsula The Yucatán Peninsula, in southeastern Mexico, separates the Caribbean Sea from the Gulf of Mexico, with the northern coastline on the Yucatán Channel. The peninsula lies east of the Isthmus of Tehuantepec, a northwestern geographic partition separating the region of Central America from the rest of North America. The Jurassic North Atlantic Ocean The Atlantic Ocean is the second-largest of the world's oceanic divisions; with a total area of about 106.4 million square kilometres . It covers approximately one-fifth of the Earth's surface. The first part of its name refers to the Atlas of Greek mythology, making the Atlantic the "Sea of Atlas". The oldest known mention of this name was relatively narrow, while the South Atlantic did not open until the following Cretaceous Period, when Gondwana itself rifted apart.[9] The Tethys Sea The Tethys Ocean was an ocean that existed between the continents of Gondwana and Laurasia during the Mesozoic era before the opening of the Indian Ocean closed, and the Neotethys The Mediterranean Basin comprises the lands around and surrounded by the Mediterranean Sea. In biogeography, the Mediterranean Basin refers to the lands around the Mediterranean Sea that have a Mediterranean climate, with mild, rainy winters and hot, dry summers, which supports characteristic Mediterranean forests, woodlands, and scrub vegetation basin appeared. Climates were warm, with no evidence of glaciation A glacier is a large mass of ice moving slowly over some land surface or down a valley, formed over long periods from the accumulation of snow in areas where the amount of snow that falls exceeds the amount that melts. The word glacier comes from French via the Vulgar Latin glacia, and ultimately from Latin glacies meaning ice. As in the Triassic, there was apparently no land near either pole, and no extensive ice caps existed.
The Jurassic geological record is good in western Europe Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural River, the Caspian Sea, and by the Caucasus Mountains to the southeast. Europe is washed upon to the north by the Arctic Ocean and, where extensive marine sequences indicate a time when much of the continent was submerged under shallow tropical seas; famous locales include the Jurassic Coast World Heritage Site A UNESCO World Heritage Site is a site that is on the list that is maintained by the international World Heritage Programme administered by the UNESCO World Heritage Committee, composed of 21 state parties which are elected by their General Assembly for a four-year term. A World Heritage Site is a place of either cultural or physical significance and the renowned late Jurassic lagerstätten of Holzmaden and Solnhofen The Solnhofen limestone is a Jurassic Konservat-Lagerstätte that preserves a rare assemblage of fossilized organisms, some of which, such as sea jellies, don't ordinarily fossilize at all. Others, like the early bird Archaeopteryx are preserved in such detail that they are among the most famous and most beautiful fossils in the world. The.[10] In contrast, the North American Jurassic record is the poorest of the Mesozoic, with few outcrops at the surface.[11] Though the epicontinental Sundance Sea left marine deposits in parts of the northern plains of the United States The United States of America is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the and Canada Canada is a country occupying most of upper North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean. It is the world's second largest country by total area and shares the world's longest common border with the United States to the south and northwest during the late Jurassic, most exposed sediments from this period are continental, such as the alluvial Alluvium is soil or sediments deposited by a river or other running water. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand and gravel deposits of the Morrison Formation The Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone and limestone and is light grey, greenish gray, or red. Most of the fossils occur in the green.
The Jurassic was a time of calcite sea A calcite sea is one in which low-magnesium calcite is the primary inorganic marine calcium carbonate precipitate. An aragonite sea is the alternate seawater chemistry in which aragonite and high-magnesium calcite are the primary inorganic carbonate precipitates. The Early Paleozoic and the Middle to Late Mesozoic oceans were predominantly calcite geochemistry in which low-magnesium calcite Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (Ca was the primary inorganic marine precipitate of calcium carbonate. Carbonate hardgrounds were thus very common, along with calcitic ooids, calcitic cements, and invertebrate faunas with dominantly calcitic skeletons (Stanley and Hardie, 1998, 1999).
The first of several massive batholiths A batholith is a large emplacement of igneous intrusive (also called plutonic) rock that forms from cooled magma deep in the Earth's crust. Batholiths are almost always made mostly of felsic or intermediate rock-types, such as granite, quartz monzonite, or diorite (see also granite dome) were emplaced in the northern Cordillera The American Cordillera consists of an essentially continuous sequence of mountain ranges that form the western "backbone" of North America, Central America and South America. From north to south, this sequence of overlapping and parallel ranges begins with the Alaska Range and the Brooks Range in Alaska and run through the Yukon into beginning in the mid-Jurassic, marking the Nevadan orogeny The Nevadan Orogeny was a major mountain building event that took place along the western edge of ancient North America between the Mid to Late Jurassic . The Nevadan orogeny was the first of three major mountain building episodes to transform Western North America between the Late Mesozoic and Early Cenozoic Eras, the latter two being the Sevier.[12] Important Jurassic exposures are also found in Russia Russia (pronounced /ˈrʌʃə/ ; Russian: Россия, pronounced [rʌˈsʲijə]), officially known as both Russia and the Russian Federation(Russian: Российская Федерация (help·info), Rossiyskaya Federatsiya), is a country in northern Eurasia (Europe and Asia together). It is a semi-presidential republic, comprising 83, India India, officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal on the east, India has a coastline of 7,517, South America South America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. It is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the, Japan Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. The characters which make up Japan's name mean "sun-origin", which, Australasia, and the United Kingdom.
Africa
Early Jurassic strata are distributed in a similar fashion to Late Triassic beds, with more common outcrops in the south and less common fossil beds which are predominated by tracks to the north.[13] As the Jurassic proceeded, larger and more iconic groups of dinosaurs like sauropods and ornithopods proliferated in Africa.[13] Middle Jurassic strata are neither well represented nor well studied in Africa.[13] Late Jurassic strata are also poorly represented apart from the spectacular Tendeguru fauna in Tanzania.[13] The Late Jurassic life of Tendeguru is very similar to that found in western North America's Morrison Formation.[13]
Fauna
Large dinosaurs were dominant during the Jurassic Period. Ichthyosaurus from Liassic oil slates in Holzmaden, southern Germany. Gastropod and attached mytilid bivalves on a Jurassic limestone bedding plane in southern Israel. Gigandipus, a dinosaur footprint in the Lower Jurassic Moenave Formation at the St. George Dinosaur Discovery Site at Johnson Farm, southwestern Utah.Aquatic and marine
During the Jurassic, the primary vertebrates living in the seas were fish and marine reptiles. The latter include ichthyosaurs, plesiosaurs and marine crocodiles, of the families Teleosauridae and Metriorhynchidae.
In the invertebrate world, several new groups appeared, including rudists (a reef-forming variety of bivalves) and belemnites. The Jurassic also had diverse encrusting and boring (sclerobiont) communities (see Taylor & Wilson, 2003), and it saw a significant rise in the bioerosion of carbonate shells and hardgrounds. Especially common is the ichnogenus (trace fossil) Gastrochaenolites.
During the Jurassic period about four or five of the twelve clades of planktonic organisms that exist in the fossil record either experienced a massive evolutionary radiation or appeared for the first time.[8]
Terrestrial
On land, large archosaurian reptiles remained dominant. The Jurassic was the golden age of the large herbivorous dinosaurs known as the sauropods—Camarasaurus, Apatosaurus, Diplodocus, Brachiosaurus, and many others—that roamed the land late in the period; their mainstays were either the prairies of ferns, palm-like cycads and bennettitales, or the higher coniferous growth, according to their adaptations. They were preyed upon by large theropods as for example Ceratosaurus, Megalosaurus, Torvosaurus and Allosaurus. All these belong to the 'lizard hipped' or saurischian branch of the dinosaurs. During the Late Jurassic, the first birds evolved from small coelurosaurian dinosaurs. Ornithischian dinosaurs were less predominant than saurischian dinosaurs, although some like stegosaurs and small ornithopods played important roles as small and medium-to-large (but not sauropod-sized) herbivores. In the air, pterosaurs were common; they ruled the skies, filling many ecological roles now taken by birds.
Flora
Conifers were common in the Jurassic period.The arid, continental conditions characteristic of the Triassic steadily eased during the Jurassic period, especially at higher latitudes; the warm, humid climate allowed lush jungles to cover much of the landscape.[14] Gymnosperms were relatively diverse during the Jurassic period.[8] The Conifers in particular dominated the flora, as during the Triassic; they were the most diverse group and constituted the majority of large trees. Extant conifer families that flourished during the Jurassic included the Araucariaceae, Cephalotaxaceae, Pinaceae, Podocarpaceae, Taxaceae and Taxodiaceae.[15] The extinct Mesozoic conifer family Cheirolepidiaceae dominated low latitude vegetation, as did the shrubby Bennettitales.[16] Cycads were also common, as were ginkgos and Dicksoniaceous tree ferns in the forest.[8] Smaller ferns were probably the dominant undergrowth. Caytoniaceous seed ferns were another group of important plants during this time and are thought to have been shrub to small-tree sized.[17] Ginkgo plants were particularly common in the mid- to high northern latitudes.[8] In the Southern Hemisphere, podocarps were especially successful, while Ginkgos and Czekanowskiales were rare.[14][16]
In the oceans modern coralline algae appeared for the first time.[8]
Notes
- ^ Image:Sauerstoffgehalt-1000mj.svg
- ^ Image:Phanerozoic Carbon Dioxide.png
- ^ Image:All palaeotemps.png
- ^ a b Hölder, H. 1964. Jura - Handbuch der stratigraphischen Geologie, IV. Enke-Verlag, 603 pp., 158 figs, 43 tabs; Stuttgart
- ^ a b Arkell, W.J. 1956. Jurassic Geology of the World. Oliver & Boyd, 806 pp.; Edinburgh und London.
- ^ a b Pieńkowski, G.; Schudack, M.E.; Bosák, P.; Enay, R.; Feldman-Olszewska, A.; Golonka, J.; Gutowski, J.; Herngreen, G.F.W.; Jordan, P.; Krobicki, M.; Lathuiliere, B.; Leinfelder, R.R.; Michalík, J.; Mönnig, E.; Noe-Nygaard, N.; Pálfy, J.; Pint, A.; Rasser, M.W.; Reisdorf, A.G.; Schmid, D.U.; Schweigert, G.; Surlyk, F.; Wetzel, A. & Theo E. Wong, T.E. 2008. Jurassic. In: McCann, T. (ed.): The Geology of Central Europe. Volume 2: Mesozoic and Cenozoic, Geological Society, pp.: 823-922; London.
- ^ Rollier, L. 1903. Das Schweizerische Juragebirge. Sonderabdruck aus dem Geographischen Lexikon der Schweiz, Verlag von Gebr. Attinger, 39 pp; Neuenburg
- ^ a b c d e f Kazlev, M. Alan (2002) Palaeos website Accessed July. 22, 2008
- ^ Late Jurassic
- ^ Jurassic Period
- ^ map
- ^ Monroe and Wicander, 607.
- ^ a b c d e Jacobs, Louis, L. (1997). "African Dinosaurs." Encyclopedia of Dinosaurs. Edited by Phillip J. Currie and Kevin Padian. Academic Press. p. 2-4.
- ^ a b Haines, 2000.
- ^ Behrensmeyer et al., 1992, 349.
- ^ a b Behrensmeyer et al., 1992, 352
- ^ Behrensmeyer et al., 1992, 353
References
| Geology portal |
| Paleontology portal |
| Time portal |
- Behrensmeyer, Anna K., Damuth, J.D., DiMichele, W.A., Potts, R., Sues, H.D. & Wing, S.L. (eds.) (1992), Terrestrial Ecosystems through Time: the Evolutionary Paleoecology of Terrestrial Plants and Animals, University of Chicago Press, Chicago and London, ISBN 0-226-04154-9 (cloth), ISBN 0-226-04155-7 (paper)
- Haines, Tim (2000) Walking with Dinosaurs: A Natural History, New York: Dorling Kindersley Publishing, Inc., p. 65. ISBN 0-563-38449-2
- Kazlev, M. Alan (2002) Palaeos website Accessed Jan. 8, 2006
- Mader, Sylvia (2004) Biology, eighth edition
- Monroe, James S., and Reed Wicander. (1997) The Changing Earth: Exploring Geology and Evolution, 2nd ed. Belmont: West Publishing Company, 1997. ISBN 0-314-09577-2
- Ogg, Jim; June, 2004, Overview of Global Boundary Stratotype Sections and Points (GSSP's) http://www.stratigraphy.org/gssp.htm Accessed April 30, 2006.
- Stanley, S.M. and Hardie, L.A. (1998). "Secular oscillations in the carbonate mineralogy of reef-building and sediment-producing organisms driven by tectonically forced shifts in seawater chemistry". Palaeogeography, Palaeoclimatology, Palaeoecology 144: 3-19.
- Stanley, S.M. and Hardie, L.A. (1999). "Hypercalcification; paleontology links plate tectonics and geochemistry to sedimentology". GSA Today 9: 1-7.
- Taylor, P.D. and Wilson, M.A., 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62: 1-103. [1].
External links
| Look up jurassic in Wiktionary, the free dictionary. |
| Wikimedia Commons has media related to: Jurassic |
| Jurassic period | ||
|---|---|---|
| Lower/Early Jurassic | Middle Jurassic | Upper/Late Jurassic |
| Hettangian | Sinemurian Pliensbachian | Toarcian | Aalenian | Bajocian Bathonian | Callovian | Oxfordian | Kimmeridgian Tithonian |
| Preceded by Proterozoic eon | 542 Ma - Phanerozoic eon - Present | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 542 Ma - Paleozoic era - 251 Ma | 251 Ma - Mesozoic era - 65 Ma | 65 Ma - Cenozoic era - Present | ||||||||||
| Cambrian | Ordovician | Silurian | Devonian | Carboniferous | Permian | Triassic | Jurassic | Cretaceous | Paleogene | Neogene | Quaternary | |
Categories: Jurassic
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Schenectady Gazette, NY
By Mike MacAdam Watching the Cleveland Indians drop 14 runs on the Yankees in the second inning on Saturday reminded me of a line from " Jurassic Park," after Laura Dern's character rips into the developer of the park, played by Richard Attenborough. ...
everyone's foroobject wists
2009-04-24 15:00:00
The Bartini Beriev is one of those objects that scores on every level of . Jurassic. technology fetishism: highly unusual experimental design (check); looks like something from science fiction (check); Soviet (check); abandoned and rotting ...
Q. How did they die? I am a dino-freak, and I love all the movies, ever since I was 4, butI never knew what happened to them, obviously they were eaten by something, but what?... Please help me out here.
Asked by jojosills14 - Tue Mar 31 10:42:33 2009 - - 4 Answers - 0 Comments
A. Or a aquatic/marine dinosaur attacked the boat and killed them, or a flying one flew down and get them. I think some of the camara shots to the water suggest that something from there attacked them.
Answered by Darth Eugene Vader - Tue Mar 31 11:20:22 2009
