title: Greater Manchester

text: Greater Manchester lies at the heart of the North West transport network. Much of the infrastructure converges at Manchester city centre with the Manchester Inner Ring Road, an amalgamation of several major roads, circulating the city centre. The county is the only place in the UK to have a fully orbital motorway, the M60, which passes through all of the boroughs except Bolton and Wigan. Greater Manchester has a higher percentage of the motorway network than any other county in the country, and according to the "Guinness Book of World Records", it has the most traffic lanes side by side (17), spread across several parallel carriageways (M61 at Linnyshaw in Walkden, close to the M60 interchange). Greater Manchester's of motorway network saw 5.8 billion vehicle kilometres in 2002 – about 6% of the UK's total, or 89,000 vehicles a day. The A580 "East Lancs" road is a primary A road that connects Manchester and Salford with Liverpool. It was the UK's first purpose-built intercity highway and was officially opened by George V on 18 July 1934. Throughout 2008, there were proposals for congestion charging in Greater Manchester. Unlike the London scheme, two cordons would have been used, one covering the main urban core of the Greater Manchester Urban Area and another covering Manchester city centre.


title: Greater Manchester

text: Metrolink is Greater Manchester's light rail system, which began operating in 1992. Principally used for suburban commuting, as of December 2020 the long network consists of eight lines which radiate from Manchester city centre and terminate at Altrincham, Ashton-under-Lyne, Bury, East Didsbury, Eccles, MediaCityUK, Manchester Airport, Rochdale and Trafford Centre. The system is owned by TfGM and operated and maintained under contract by a Keolis / Amey consortium. Greater Manchester has a heavy rail network of 142 route miles (229 km) with 98 stations, forming a central hub to the North West rail network. Train services are provided by private operators and run on the national rail network which is owned and managed by Network Rail. There is an extensive bus network which radiates from Manchester city centre. The largest providers are Diamond Bus North West, First Greater Manchester, Go North West and Stagecoach Manchester. An extensive canal network also remains from the Industrial Revolution.


title: Greater Manchester

text: Manchester Airport, which is the third busiest in the United Kingdom, serves the county and wider region with flights to more worldwide destinations than any other airport in the UK. Since June 2007 it has served 225 routes. The airport handled 21.06  million passengers in 2008.


title: Greater Manchester

text: The three modes of public surface transport in the area are heavily used. 19.7 million rail journeys were made in the then GMPTE-supported area in the 2005/2006 financial year – an increase of 9.4% over 2004/2005; there were 19.9 million journeys on Metrolink; and the bus system carried 219.4 million passengers.


title: Greater Manchester

text: Manchester hosted the 2002 Commonwealth Games which was, at a cost of £200M for the sporting facilities and a further £470M for local infrastructure, by far the biggest and most expensive sporting event held in the UK at the time and the first to be an integral part of urban regeneration. A mix of new and existing facilities were used. New amenities included the Manchester Aquatics Centre, Bolton Arena, the National Squash Centre, and the City of Manchester Stadium. The Manchester Velodrome was built as part of the Manchester bid for the 2000 Summer Olympics. After the Commonwealth Games the City of Manchester Stadium was converted for football use, and the adjacent warm-up track upgraded to become the Manchester Regional Arena. Other facilities continue to be used by elite athletes. Cambridge Policy Consultants estimate 4,500 full-time jobs as a direct consequence, and Grattan points to other long-term benefits accruing from publicity and the improvement of the area's image.


title: Greater Manchester

text: Association football is "woven into the cultural fabric of Greater Manchester", by way of its numerous football clubs – two of which play in the Premier League – which draw support, visitors and economic benefits to Greater Manchester valued at £330 million per year as of 2013. The Manchester Football Association is the sport's governing body in Greater Manchester, and is committed to its promotion and development. Manchester United F.C. are one of the world's best-known football teams, and in 2008 and 2017 "Forbes" estimated that they were the world's richest club. They have won the League Championship a record twenty times (most recently in 2012–2013), the FA Cup twelve times, the Football League Cup five times and have been European Champions three times. Their Old Trafford ground has hosted the FA Cup Final, England international matches and the 2003 UEFA Champions League Final between Juventus and A.C. Milan. Manchester City F.C. moved from Maine Road to the City of Manchester Stadium after the 2002 Commonwealth Games. They have won the league championship seven times (most recently in 2020–21), the FA Cup six times and the Football League Cup eight times. Wigan Athletic F.C. are one of the county's younger sides and won their first major trophy in 2013, defeating Manchester City F.C. in the FA Cup final. They currently play in the Championship, while Bolton Wanderers F.C. play in League One. Below that are League Two sides Rochdale A.F.C., Salford City F.C., Stockport County F.C. and National League side Oldham Athletic A.F.C.


title: Greater Manchester

text: In rugby league, Wigan Warriors, Leigh Centurions, and Salford Red Devils compete in the Super League, the top-level professional rugby league football club competition in Europe. Wigan have won the Super League/Rugby Football League Championship twenty–one times, the Challenge Cup nineteen times, and the World Club Challenge three times. Swinton Lions, and Oldham R.L.F.C. play in the second tier Championship, whilst Rochdale Hornets play in the third tier League 1 There is also a large network of junior/community rugby league clubs across the metropolitan area which act as feeder teams to the elite sides, the most notable being Manchester Rangers. In rugby union, Sale Sharks compete in the Guinness Premiership, and won the league in 2006. Whitefield based Sedgley Park RUFC compete in National Division One, Manchester RUFC in National Division Two and Wigan side Orrell R.U.F.C. in National Division Three North.


title: Greater Manchester

text: Lancashire County Cricket Club began as Manchester Cricket Club and represents the (ancient) county of Lancashire. Lancashire contested the original 1890 County Championship. The team has won the County Championship nine times, most recently in 2011. Their Old Trafford ground, near the football stadium of the same name, regularly hosts test matches. Possibly the most famous took place in 1956, when Jim Laker took a record nineteen wickets in the fourth test against Australia. Cheshire County Cricket Club are a minor counties club who sometimes play in the south of the county.


title: Greater Manchester

text: The National Speedway Stadium in Gorton is the home to top-flight speedway team the Belle Vue Aces, and the Manchester Titans American football club. Greater Manchester was previously home to the largest Greyhound racing track in the United Kingdom, the Belle Vue Stadium, which closed in 2020. Professional ice hockey is held at the purpose-designed rink in Altrincham, the Altrincham Ice Dome, which host the Manchester Storm of the Elite Ice Hockey League and the Altrincham Aces of the National Ice Hockey League.


title: Greater Manchester

text: Horse racing has taken place at several sites in the county. The two biggest courses were both known as Manchester Racecourse – though neither was within the boundaries of Manchester – and ran from the 17th century until 1963. Racing was at Kersal Moor until 1847 when the racecourse at Castle Irwell was opened. In 1867 racing was moved to New Barnes, Weaste, until the site was vacated (for a hefty price) in 1901 to allow an expansion to Manchester Docks. The land is now home to Dock 9 of the re-branded Salford Quays. Racing then moved back to Castle Irwell which later staged a Classic – the 1941 St. Leger – and was home to the Lancashire Oaks (nowadays run at Haydock Park) and the November Handicap, which was traditionally the last major race of the flat season. Through the late-1950s and early-1960s the track saw Scobie Breasley and Lester Piggott annually battle out the closing acts of the jockey's title until racing ceased on 7 November 1963.


title: Greater Manchester

text: The Greater Manchester Athletics Association is the governing body of athletics in Greater Manchester, and organises events and competitions within Greater Manchester. The Greater Manchester Marathon is a long-distance running event along a 26-mile and 385-yard course throughout the borough of Trafford. Professional athletics takes place at the Regional Athletics Arena in Sportcity, which has hosted numerous national trials, Robin Park in Wigan, Longford Park in Stretford (home to Trafford Athletic Club), Woodbank Stadium in Stockport (home to Stockport Harriers) and the Cleavleys Track in Winton (home to Salford Harriers). The 12,000seat Leigh Sports Village is a stadium and athletics venue home to the Leigh Harriers, Leigh Centurions Rugby League Club and the Manchester United W.F.C..


title: Greater Manchester

text: The Greater Manchester Community Basketball Club is an association which represents Greater Manchester in basketball. It supports a variety of teams, including Manchester Magic. The Greater Manchester County Crown Green Bowling Association appoints Junior, Senior and Veteran teams to represent Greater Manchester in the sport of bowls. Founded by Greater Manchester's ten district councils in 1996, GreaterSport is the County Sports Partnership for Greater Manchester which works closely with the sports and physical activity sectors and coordinates events such as the Greater Manchester Youth Games. The Greater Manchester Sports Fund aims to ensure that people in Greater Manchester aged 12–21 competing in any kind of sport, irrespective of background, are able to obtain grants of up to £750 so that they can better fulfil their potential.


title: Greater Manchester

text: Art, tourism, culture and sport provide 16% of employment in Greater Manchester, with the proportion highest in Manchester. In 2014, Will Straw remarked that "Greater Manchester is a creative powerhouse", recognised for its cultural output in areas such as association football, media and digital content, and guitar and dance music. Since the industrial revolution, Greater Manchester has shared a rivalry with the nearby Liverpool, based on economic and industrial competition.


title: Greater Manchester

text: There are several delicacies native to Greater Manchester. Savoury dishes include black pudding, a blood sausage typically associated with Bury and Bury Market; pasty barm, a combined pasty-barm cake created in Bolton; and rag pudding, a suet pastry pudding from Oldham filled with steak and onion and steamed in a cloth or wrapper to cook; the Manchester egg was introduced in 2010. Sweet dishes include Eccles cake — native to Eccles — a small round flaky pastry cake filled with currants, sugar and spice; Manchester tart, a baked tart which consists of a shortcrust pastry shell spread with raspberry jam, covered with a custard filling and topped with flakes of coconut; and Uncle Joe's Mint Balls, traditional sweet mild mints manufactured in Wigan since their inception in 1898. Vimto and Tizer are soft drinks invented in Manchester in 1908 and 1924 respectively. Boddingtons is a bitter developed in Manchester and promoted as the "Cream of Manchester" in a popular 1990s advertising campaign credited with raising the city's profile.


title: Greater Manchester

text: The Greater Manchester Campaign for Real Ale is a branch of the national Campaign for Real Ale, an advocacy group that supports, promotes and preserves the beer and drinks industry, and recognising outstanding venues with awards; The Nursery in Heaton Norris was its National Pub of the Year in 2001, and The Baum in Rochdale was its National Pub of the Year in 2012. The Manchester Food and Drink Festival was launched in 1997 as an urban beverage and gastronomy fair, principally held in Manchester city centre with further events throughout Greater Manchester; smaller separate local events include the Prestwich Food and Drink Festival, the annual World Pie Eating Championship in Wigan, and the annual Ramsbottom Chocolate Festival. As of 2020 Manchester has 1 Michelin Star restaurant: Mana, which is still retained presently. The region also has three eateries in the Bib Gourmand category.


title: Greater Manchester

text: The Greater Manchester Museums Group (GMMG) is a partnership of eight of the ten Museum Services in Greater Manchester. Its exhibition centres include: Gallery Oldham, which has in the past featured work by Pablo Picasso; Salford Museum and Art Gallery, a local museum with a recreated Victorian street; and Bolton Museum, which houses material from private collectors, including geological specimens from the estate of Caroline Birley. Separate from the GMMG is The Lowry at Salford Quays, which has a changing display of L. S. Lowry's work alongside travelling exhibitions. Manchester Art Gallery is a major provincial art gallery noted for its collection of Pre-Raphaelite art and housed in a Grade I listed building by Charles Barry.


title: Greater Manchester

text: Greater Manchester's museums showcase the county's industrial and social heritage. The Hat Works in Stockport is the UK's only museum dedicated to the hatting industry; the museum moved in 2000 to a Grade II listed Victorian mill, previously a hat factory. The Museum of Science and Industry in Manchester, amongst other displays, charts the rise of science and industry and especially the part Manchester played in its development; the Museums, Libraries and Archives Council described the displays as "pre-eminent collections of national and international importance". Urbis began its life as a museum of the modern city, which attempted to explain the effects and experiences of life in the city. It was then transformed into an exhibition centre, which had its most successful year in 2006. Urbis entered its third phase since opening in 2012 as the National Football Museum. Stockport Air Raid Shelters uses a mile of tunnels, built to accommodate 6,500 people, to illustrate life in the Second World War's air raid shelters. The Imperial War Museum North in Trafford Park is one of the Imperial War Museum's five branches. Alongside exhibitions of war machinery are displays describing how people's lives are affected by war. The Museum of Transport in Manchester, which opened in 1979, has one of the largest collections of vehicles in the country. The People's History Museum is "the national centre for the collection, conservation, interpretation and study of material relating to the history of working people in Britain". The Pankhurst Museum is based in the early feminist Emmeline Pankhurst's former home and includes a parlour laid out in contemporary style. Manchester United, Manchester City, and Lancashire CCC all have dedicated museums illustrating their histories. Wigan Pier, best known from George Orwell's book "The Road to Wigan Pier", was the name of a wharf on the Leeds and Liverpool Canal in Wigan. It will re-open as a visitor attraction in 2023, after years of closure. The town is also home to the Museum of Wigan Life.


title: Greater Manchester

text: The Greater Manchester Film Festival was launched in 2012. It is an international film festival designed to capitalise on Greater Manchester's "huge strengths in film and television, along with its growing media presence". MediaCityUK, a host venue of the Greater Manchester Film Festival, is a mixed-use property development site at Salford Quays; its principal tenants are mass media organisations such as ITV Granada and the BBC. One of Greater Manchester's most lucrative and acclaimed television exports is "Coronation Street", which is a televised soap opera set in Weatherfield, a fictional borough of Greater Manchester, inspired by life in Salford. Created by Tony Warren, "Coronation Street" was first broadcast on 9 December 1960, making it the world's longest-running TV soap opera in production. It has been filmed in Manchester at Granada Studios since its inception, but filming is now done at a new set at MediaCityUK.


title: Greater Manchester

text: A local television station for Greater Manchester, Channel M, was launched in February 2000, carrying a wide range of local programming, including news, sport and entertainment programming. Following severe cutbacks to its local production amid heavy losses, the station ceased broadcasting in April 2012. A smaller-scale local TV station, That's Manchester, began broadcasting in May 2015.


title: Greater Manchester

text: The "Manchester Evening News" is a regional daily newspaper covering Greater Manchester, published every day except Sunday. It is owned by Reach plc and produced by MEN Media. It sells around 81,000 copies a day and gives away nearly 100,000, making it the market leader in Greater Manchester. The paper was first published in 1868 by Mitchell Henry as part of his parliamentary election campaign for the Manchester constituency. MEN Media "dominates Greater Manchester", reaching 7 out of 10 adults each week within the region through its portfolio of products which also includes the "Oldham Advertiser", the "Rochdale Observer", and the "Salford Advertiser".


title: Greater Manchester

text: Greater Manchester has the highest number of theatre seats per head of population outside London. Most, if not all, of the larger theatres are subsidised by local authorities or the North West Regional Arts Board. The Royal Exchange Theatre formed in the 1970s out of a peripatetic group staging plays at venues such as at the University [of Manchester] Theatre and the Apollo Theatre. A season in a temporary stage in the former Royal Exchange, Manchester was followed by funding for a theatre in the round, which opened in 1976. The Lowry — Greater Manchester's most visited tourist attraction — houses two theatres, used by travelling groups in all the performing arts. The Opera House is a 1,900-seat venue hosting travelling productions, often musicals just out of the West End. Its sister venue, The Palace, hosts generally similar shows. The Oldham Playhouse, one of the older theatres in the region, helped launch the careers of Stan Laurel and Charlie Chaplin. Its productions are described by the 2007 CityLife guide as 'staunchly populist' – and popular. There are many other venues scattered throughout the county, of all types and sizes.


title: Greater Manchester

text: Greater Manchester has four professional orchestras, all based in Manchester. The Hallé Orchestra is the UK's oldest symphony orchestra (and the fourth oldest in the world), supports a choir and a youth orchestra, and releases its recordings on its own record label. The Hallé is based at the Bridgewater Hall but often tours, typically giving 70 performances "at home" and 40 on tour. The BBC Philharmonic Orchestra, one of five BBC orchestras is based in MediaCityUK in Salford. It can trace its history back to the early days of radio broadcasting in 1926. The Manchester Camerata and the Northern Chamber Orchestra are smaller, though still professional, organisations. The main classical venue is the 2,341-seat Bridgewater Hall in Manchester, opened in 1996 at a cost of £42m.


title: Greater Manchester

text: Manchester is also a centre for musical education, via the Royal Northern College of Music and Chetham's School of Music.


title: Greater Manchester

text: The Manchester Arena holds over 21,000 people, and is the largest indoor arena in the United Kingdom. It has been voted "International Venue of the Year", and for several years was the most popular venue in the world. The 23,500-seat Co-op Live arena is under construction in Greater Manchester, it will open in 2023. Sports grounds in Greater Manchester, such as the City of Manchester Stadium, also host large live-music events. A £200million flexible, large-scale cultural, arts, and exhibition space named The Factory is under construction on the former site of Granada Studios in central Manchester. It is named with reference to Factory Records, a Manchester-based independent record label, founded in 1978 by Tony Wilson and Alan Erasmus. Factory Records – which featured acts such as Joy Division, New Order, and the Happy Mondays — and The Haçienda, served as a catalyst in the late-1980s for a blending of alternative rock, psychedelic rock and electronic dance music known as Madchester. Greater Manchester continues to be associated with guitar and dance music.


title: Jurassic

text: The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified.


title: Jurassic

text: The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined.


title: Jurassic

text: By the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses: Laurasia to the north and Gondwana to the south. The climate of the Jurassic was warmer than the present, and there were no ice caps. Forests grew close to the poles, with large arid expanses in the lower latitudes.


title: Jurassic

text: On land, the fauna transitioned from the Triassic fauna, dominated jointly by dinosauromorph and pseudosuchian archosaurs, to one dominated by dinosaurs alone. The first birds appeared during the Jurassic, evolving from a branch of theropod dinosaurs. Other major events include the appearance of the earliest lizards and the evolution of therian mammals. Crocodylomorphs made the transition from a terrestrial to an aquatic life. The oceans were inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, while pterosaurs were the dominant flying vertebrates. The first sharks, rays and crabs also first appeared during the period.


title: Jurassic

text: The chronostratigraphic term "Jurassic" is linked to the Jura Mountains, a forested mountain range that mainly follows the France–Switzerland border. The name "Jura" is derived from the Celtic root "*jor" via Gaulish "*iuris" "wooded mountain", which was borrowed into Latin as a name of a place and evolved into "Juria" and finally "Jura".


title: Jurassic

text: During a tour of the region in 1795, German naturalist Alexander von Humboldt recognized carbonate deposits within the Jura Mountains as geologically distinct from the Triassic aged Muschelkalk of Southern Germany, but he erroneously concluded that they were older. He then named them ('Jura limestone') in 1799.


title: Jurassic

text: In 1829, the French naturalist Alexandre Brongniart published a book entitled "Description of the Terrains that Constitute the Crust of the Earth or Essay on the Structure of the Known Lands of the Earth." In this book, Brongniart used the phrase "terrains jurassiques" when correlating the "Jura-Kalkstein" of Humboldt with similarly aged oolitic limestones in Britain, thus coining and publishing the term "Jurassic".


title: Jurassic

text: The German geologist Leopold von Buch in 1839 established the three-fold division of the Jurassic, originally named from oldest to the youngest: the Black Jurassic, Brown Jurassic, and White Jurassic. The term "Lias" had previously been used for strata of equivalent age to the Black Jurassic in England by William Conybeare and William Phillips in 1822.


title: Jurassic

text: The French palaeontologist Alcide d'Orbigny in papers between 1842 and 1852 divided the Jurassic into ten stages based on ammonite and other fossil assemblages in England and France, of which seven are still used, but none has retained its original definition. The German geologist and palaeontologist Friedrich August von Quenstedt in 1858 divided the three series of von Buch in the Swabian Jura into six subdivisions defined by ammonites and other fossils.


title: Jurassic

text: The German palaeontologist Albert Oppel in his studies between 1856 and 1858 altered d'Orbigny's original scheme and further subdivided the stages into biostratigraphic zones, based primarily on ammonites. Most of the modern stages of the Jurassic were formalized at the Colloque du Jurassique à Luxembourg in 1962.


title: Jurassic

text: The 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. Geologists divide the rocks of the Jurassic into a stratigraphic set of units called stages, each formed during corresponding time intervals called ages.


title: Jurassic

text: Stages can be defined globally or regionally. For global stratigraphic correlation, the International Commission on Stratigraphy (ICS) ratify global stages based on a Global Boundary Stratotype Section and Point (GSSP) from a single formation (a stratotype) identifying the lower boundary of the stage. The ages of the Jurassic from youngest to oldest are as follows:


title: Jurassic

text: Jurassic stratigraphy is primarily based on the use of ammonites as index fossils. The first appearance datum of specific ammonite taxa is used to mark the beginnings of stages, as well as smaller timespans within stages, referred to as "ammonite zones"; these, in turn, are also sometimes subdivided further into subzones. Global stratigraphy is based on standard European ammonite zones, with other regions being calibrated to the European successions.


title: Jurassic

text: The oldest part of the Jurassic Period has historically been referred to as the Lias or Liassic, roughly equivalent in extent to the Early Jurassic, but also including part of the preceding Rhaetian. The Hettangian Stage was named by Swiss palaeontologist Eugène Renevier in 1864 after Hettange-Grande in north-eastern France. The GSSP for the base of the Hettangian is located at the Kuhjoch Pass, Karwendel Mountains, Northern Calcareous Alps, Austria; it was ratified in 2010. The beginning of the Hettangian, and thus the Jurassic as a whole, is marked by the first appearance of the ammonite "Psiloceras spelae tirolicum" in the Kendlbach Formation exposed at Kuhjoch. The base of the Jurassic was previously defined as the first appearance of "Psiloceras planorbis" by Albert Oppel in 1856–58, but this was changed as the appearance was seen as too localised an event for an international boundary.


title: Jurassic

text: The Sinemurian Stage was first defined and introduced into scientific literature by Alcide d'Orbigny in 1842. It takes its name from the French town of Semur-en-Auxois, near Dijon. The original definition of Sinemurian included what is now the Hettangian. The GSSP of the Sinemurian is located at a cliff face north of the hamlet of East Quantoxhead, 6 kilometres east of Watchet, Somerset, England, within the Blue Lias, and was ratified in 2000. The beginning of the Sinemurian is defined by the first appearance of the ammonite "Vermiceras quantoxense."


title: Jurassic

text: Albert Oppel in 1858 named the Pliensbachian Stage after the hamlet of Pliensbach in the community of Zell unter Aichelberg in the Swabian Alb, near Stuttgart, Germany. The GSSP for the base of the Pliensbachian is found at the Wine Haven locality in Robin Hood's Bay, Yorkshire, England, in the Redcar Mudstone Formation, and was ratified in 2005. The beginning of the Pliensbachian is defined by the first appearance of the ammonite "Bifericeras donovani".


title: Jurassic

text: The village Thouars (Latin: "Toarcium"), just south of Saumur in the Loire Valley of France, lends its name to the Toarcian Stage. The Toarcian was named by Alcide d'Orbigny in 1842, with the original locality being Vrines quarry around 2 km northwest of Thouars. The GSSP for the base of the Toarcian is located at Peniche, Portugal, and was ratified in 2014. The boundary is defined by the first appearance of ammonites belonging to the subgenus "Dactylioceras" ("Eodactylites")"."


title: Jurassic

text: The Aalenian is named after the city of Aalen in Germany. The Aalenian was defined by Swiss geologist Karl Mayer-Eymar in 1864. The lower boundary was originally between the dark clays of the Black Jurassic and the overlying clayey sandstone and ferruginous oolite of the Brown Jurassic sequences of southwestern Germany. The GSSP for the base of the Aalenian is located at Fuentelsaz in the Iberian range near Guadalajara, Spain, and was ratified in 2000. The base of the Aalenian is defined by the first appearance of the ammonite "Leioceras opalinum".


title: Jurassic

text: Alcide d'Orbigny in 1842 named the Bajocian Stage after the town of Bayeux (Latin: "Bajoce") in Normandy, France. The GSSP for the base of the Bajocian is located in the Murtinheira section at Cabo Mondego, Portugal; it was ratified in 1997. The base of the Bajocian is defined by the first appearance of the ammonite "Hyperlioceras mundum."


title: Jurassic

text: The Bathonian is named after the city of Bath, England, introduced by Belgian geologist d'Omalius d'Halloy in 1843, after an incomplete section of oolitic limestones in several quarries in the region. The GSSP for the base of the Bathonian is Ravin du Bès, Bas-Auran area, Alpes de Haute Provence, France; it was ratified in 2009. The base of the Bathonian is defined by the first appearance of the ammonite "Gonolkites convergens", at the base of the "Zigzagiceras zigzag" ammonite zone"."


title: Jurassic

text: The Callovian is derived from the Latinized name of the village of Kellaways in Wiltshire, England, and was named by Alcide d'Orbigny in 1852, originally the base at the contact between the Forest Marble Formation and the Cornbrash Formation. However, this boundary was later found to be within the upper part of the Bathonian. The base of the Callovian does not yet have a certified GSSP. The working definition for the base of the Callovian is the first appearance of ammonites belonging to the genus "Kepplerites."


title: Jurassic

text: The Oxfordian is named after the city of Oxford in England and was named by Alcide d'Orbigny in 1844 in reference to the Oxford Clay. The base of the Oxfordian lacks a defined GSSP. W. J. Arkell in studies in 1939 and 1946 placed the lower boundary of the Oxfordian as the first appearance of the ammonite "Quenstedtoceras mariae" (then placed in the genus "Vertumniceras"). Subsequent proposals have suggested the first appearance of "Cardioceras redcliffense" as the lower boundary.


title: Jurassic

text: The village of Kimmeridge on the coast of Dorset, England, is the origin of the name of the Kimmeridgian. The stage was named by Alcide d'Orbigny in 1842 in reference to the Kimmeridge Clay. The GSSP for the base of the Kimmeridgian is the Flodigarry section at Staffin Bay on the Isle of Skye, Scotland, which was ratified in 2021. The boundary is defined by the first appearance of ammonites marking the boreal Bauhini Zone and the subboreal Baylei Zone.


title: Jurassic

text: The Tithonian was introduced in scientific literature by Albert Oppel in 1865. The name Tithonian is unusual in geological stage names because it is derived from Greek mythology rather than a place name. Tithonus was the son of Laomedon of Troy and fell in love with Eos, the Greek goddess of dawn. His name was chosen by Albert Oppel for this stratigraphical stage because the Tithonian finds itself hand in hand with the dawn of the Cretaceous. The base of the Tithonian currently lacks a GSSP. The working definition for the base of the Tithonian is the first appearance of the ammonite genus "Gravesia".


title: Jurassic

text: The upper boundary of the Jurassic is currently undefined, and the Jurassic–Cretaceous boundary is currently the only system boundary to lack a defined GSSP. Placing a GSSP for this boundary has been difficult because of the strong regionality of most biostratigraphic markers, and lack of any chemostratigraphic events, such as isotope excursions (large sudden changes in ratios of isotopes), that could be used to define or correlate a boundary. Calpionellids, an enigmatic group of planktonic protists with urn-shaped calcitic tests briefly abundant during the latest Jurassic to earliest Cretaceous, have been suggested to represent the most promising candidates for fixing the Jurassic–Cretaceous boundary In particular, the first appearance "Calpionella alpina," co-inciding with the base of the eponymous Alpina subzone, has been proposed as the definition of the base of the Cretaceous. The working definition for the boundary has often been placed as the first appearance of the ammonite "Strambergella jacobi," formerly placed in the genus "Berriasella", but its use as a stratigraphic indicator has been questioned, as its first appearance does not correlate with that of "C. alpina".


title: Jurassic

text: The Kimmeridge Clay and equivalents are the major source rock for the North Sea oil. The Arabian Intrashelf Basin, deposited during the Middle and Late Jurassic, is the setting of the world's largest oil reserves, including the Ghawar Field, the world's largest oil field. The Jurassic-aged Sargelu and Naokelekan formations are major source rocks for oil in Iraq. Over 1500 gigatons of Jurassic coal reserves are found in north-west China, primarily in the Turpan-Hami Basin and the Ordos Basin.


title: Jurassic

text: Major impact structures include the Morokweng impact structure, a 70 km diameter impact structure buried beneath the Kalahari desert in northern South Africa. The impact is dated to the Tithonian, approximately 146.06 ± 0.16 Mya. Another major structure is the Puchezh-Katunki crater, 40 kilometres in diameter, buried beneath Nizhny Novgorod Oblast in western Russia. The impact has been dated to the Sinemurian, 195.9 ± 1.0 Ma.


title: Jurassic

text: At the beginning of the Jurassic, all of the world's major landmasses were coalesced into the supercontinent Pangaea, which during the Early Jurassic began to break up into northern supercontinent Laurasia and the southern supercontinent Gondwana. The rifting between North America and Africa was the first to initiate, beginning in the early Jurassic, associated with the emplacement of the Central Atlantic Magmatic Province.


title: Jurassic

text: During the Jurassic, the North Atlantic Ocean remained relatively narrow, while the South Atlantic did not open until the Cretaceous. The continents were surrounded by Panthalassa, with the Tethys Ocean between Gondwana and Asia. At the end of the Triassic, there was a marine transgression in Europe, flooding most parts of central and western Europe transforming it into an archipelago of islands surrounded by shallow seas. During the Jurassic, both the North and South Pole were covered by oceans. Beginning in the Early Jurassic, the Boreal Ocean was connected to the proto-Atlantic by the "Viking corridor" or Transcontinental Laurasian Seaway, a passage between the Baltic Shield and Greenland several hundred kilometers wide.


title: Jurassic

text: Madagascar and Antarctica began to rift away from Africa during the late Early Jurassic in association with the eruption of the Karoo-Ferrar large igneous provinces, opening the western Indian Ocean and beginning the fragmentation of Gondwana. At the beginning of the Jurassic, North and South America remained connected, but by the beginning of the Late Jurassic they had rifted apart to form the Caribbean Seaway, also known as the Hispanic Corridor, which connected the North Atlantic Ocean with eastern Panthalassa. Palaeontological data suggest that the seaway had been open since the Early Jurassic.


title: Jurassic

text: As part of the Nevadan orogeny, which began during the Triassic, the Cache Creek Ocean closed, and various terranes including the large Wrangellia Terrane accreted onto the western margin of North America. By the Middle Jurassic the Siberian plate and the North China-Amuria block had collided, resulting in the closure of the Mongol-Okhotsk Ocean.


title: Jurassic

text: During the Early Jurassic, around 190 million years ago, the Pacific Plate originated at the triple junction of the Farallon, Phoenix, and Izanagi tectonic plates, the three main oceanic plates of Panthalassa. The previously stable triple junction had converted to an unstable arrangement surrounded on all sides by transform faults because of a kink in one of the plate boundaries, resulting in the formation of the Pacific Plate at the centre of the junction. During the Middle to early Late Jurassic, the Sundance Seaway, a shallow epicontinental sea, covered much of northwest North America.The eustatic sea level is estimated to have been close to present levels during the Hettangian and Sinemurian, rising several tens of metres during the late Sinemurian–Pliensbachian before regressing to near present levels by the late Pliensbachian. There seems to have been a gradual rise to a peak of ~75 m above present sea level during the Toarcian. During the latest part of the Toarcian, the sea level again dropped by several tens of metres. It progressively rose from the Aalenian onwards, aside from dips of a few tens of metres in the Bajocian and around the Callovian–Oxfordian boundary, peaking possibly as high as 140 metres above present sea level at the Kimmeridgian–Tithonian boundary. The sea levels falls in the late Tithonian, perhaps to around 100 metres, before rebounding to around 110 metres at the Tithonian–Berriasian boundary.


title: Jurassic

text: The sea level within the long-term trends across the Jurassic was cyclical, with 64 fluctuations, 15 of which were over 75 metres. The most noted cyclicity in Jurassic rocks is fourth order, with a periodicity of approximately 410,000 years.


title: Jurassic

text: During the Early Jurassic the world's oceans transitioned from an aragonite sea to a calcite sea chemistry, favouring the dissolution of aragonite and precipitation of calcite. The rise of calcareous plankton during the Middle Jurassic profoundly altered ocean chemistry, with the deposition of biomineralized plankton on the ocean floor acting as a buffer against large CO emissions.


title: Jurassic

text: The climate of the Jurassic was generally warmer than that of present, by around 5 °C to 10 °C, with atmospheric carbon dioxide likely four times higher. Forests likely grew near the poles, where they experienced warm summers and cold, sometimes snowy winters; there were unlikely to have been ice sheets given the high summer temperatures that prevented the accumulation of snow, though there may have been mountain glaciers. Dropstones and glendonites in northeastern Siberia during the Early to Middle Jurassic indicate cold winters. The ocean depths were likely 8 °C warmer than present, and coral reefs grew 10° of latitude further north and south. The Intertropical Convergence Zone likely existed over the oceans, resulting in large areas of desert and scrubland in the lower latitudes between 40° N and S of the equator. Tropical rainforest and tundra biomes are likely to have been rare or absent.


title: Jurassic

text: The beginning of the Jurassic was likely marked by a thermal spike corresponding to the Triassic–Jurassic extinction and eruption of the Central Atlantic magmatic province. The first part of the Jurassic was marked by the Early Jurassic cool interval between 199 and 183 million years ago. It has been proposed that glaciation was present in the Northern Hemisphere during the Pliensbachian. There was a spike in global temperatures of around 4–8 °C during the early part of the Toarcian corresponding to the Toarcian Oceanic Anoxic Event and the eruption of the Karoo-Ferrar large igneous provinces in southern Gondwana, with the warm interval extending to the end of the Toarcian around 174 million years ago.


title: Jurassic

text: During the Toarcian warm interval, ocean surface temperatures likely exceeded 30 °C, and equatorial and subtropical (30°N–30°S) regions are likely to have been extremely arid, with temperatures in the interior of Pangea likely in excess of 40 °C. The Toarcian warm interval is followed by the Middle Jurassic cool interval between 174 and 164 million years ago. This is followed by the Kimmeridgian warm interval between 164 and 150 million years ago. The Pangean interior had less severe seasonal swings than in previous warm periods as the expansion of the Central Atlantic and western Indian Ocean provided new sources of moisture. The end of the Jurassic was marked by the Tithonian–early Barremian cool interval, beginning 150 million years ago and continuing into the Early Cretaceous.


title: Jurassic

text: The Toarcian Oceanic Anoxic Event (TOAE), also known as the Jenkyns Event, was an episode of widespread oceanic anoxia during the early part of the Toarcian Age, c. 183 Mya. It is marked by a globally documented high amplitude negative carbon isotope excursion, as well as the deposition of black shales and the extinction and collapse of carbonate-producing marine organisms, associated with a major rise in global temperatures.


title: Jurassic

text: The TOAE is often attributed to the eruption of the Karoo-Ferrar large igneous provinces and the associated increase of carbon dioxide concentration in the atmosphere, as well as the possible associated release of methane clathrates. This likely accelerated the hydrological cycle and increased silicate weathering, as evidenced by an increased amount of organic matter of terrestrial origin found in marine deposits during the TOAE. Groups affected include ammonites, ostracods, foraminifera, bivalves, cnidarians, and especially brachiopods, for which the TOAE represented one of the most severe extinctions in their evolutionary history. While the event had significant impact on marine invertebrates, it had little effect on marine reptiles. During the TOAE, the Sichuan Basin was transformed into a giant lake, probably three times the size of modern-day Lake Superior, represented by the Da’anzhai Member of the Ziliujing Formation. The lake likely sequestered ∼460 gigatons (Gt) of organic carbon and ∼1,200 Gt of inorganic carbon during the event. Seawater pH, which had already substantially decreased prior to the event, increased slightly during the early stages of the TOAE, before dropping to its lowest point around the middle of the event. This ocean acidification is the probable cause of the collapse of carbonate production. Additionally, anoxic conditions were exacerbated by enhanced recycling of phosphorus back into ocean water as a result of high ocean acidity and temperature inhibiting its mineralisation into apatite; the abundance of phosphorus in marine environments caused further eutrophication and consequent anoxia in a positive feedback loop.


title: Jurassic

text: The end-Jurassic transition was originally considered one of eight mass extinctions, but is now considered to be a complex interval of faunal turnover, with the increase in diversity of some groups and decline in others, though the evidence for this is primarily European, probably controlled by changes in eustatic sea level.


title: Jurassic

text: There is no evidence of a mass extinction of plants at the Triassic–Jurassic boundary. At the Triassic–Jurassic boundary in Greenland, the sporomorph (pollen and spores) record suggests a complete floral turnover. An analysis of macrofossil floral communities in Europe suggests that changes were mainly due to local ecological succession. At the end of the Triassic, the Peltaspermaceae became extinct in most parts of the world, with "Lepidopteris" persisting into the Early Jurassic in Patagonia. "Dicroidium", a seed fern that was a dominant part of Gondwanan floral communities during the Triassic, also declined at the Triassic–Jurassic boundary, surviving as a relict in Antarctica into the Sinemurian.


title: Jurassic

text: Conifers formed a dominant component of Jurassic floras. The Late Triassic and Jurassic was a major time of diversification of conifers, with most modern conifer groups appearing in the fossil record by the end of the Jurassic, having evolved from voltzialean ancestors.


title: Jurassic

text: Araucarian conifers have their first unambiguous records during the Early Jurassic, and members of the modern genus "Araucaria" were widespread across both hemispheres by the Middle Jurassic.


title: Jurassic

text: Also abundant during the Jurassic is the extinct family Cheirolepidiaceae, often recognised through their highly distinctive "Classopolis" pollen. Jurassic representatives include the pollen cone "Classostrobus" and the seed cone "Pararaucaria". Araucarian and Cheirolepidiaceae conifers often occur in association.


title: Jurassic

text: The oldest definitive record of the cypress family (Cupressaceae) is "Austrohamia minuta" from the Early Jurassic (Pliensbachian) of Patagonia, known from many parts of the plant. The reproductive structures of "Austrohamia" have strong similarities to those of the primitive living cypress genera "Taiwania" and "Cunninghamia." By the Middle to Late Jurassic Cupressaceae were abundant in warm temperate–tropical regions of the Northern Hemisphere, most abundantly represented by the genus "Elatides".


title: Jurassic

text: Members of the extinct genus "Schizolepidopsis" which likely represent a stem-group to the pine family (Pinaceae), were widely distributed across Eurasia during the Jurassic. The oldest unambiguous record of Pinaceae is the pine cone "Eathiestrobus", known from the Late Jurassic (Kimmeridgian) of Scotland, which remains the only known unequivocal fossil of the group before the Cretaceous. Despite being the earliest known member of the Pinaceae, "Eathiestrobus" appears to be a member of the pinoid clade of the family, suggesting that the initial diversification of Pinaceae occurred earlier than has been found in the fossil record.


title: Jurassic

text: During the Early Jurassic, the flora of the mid-latitudes of Eastern Asia were dominated by the extinct deciduous broad leafed conifer "Podozamites," which appears to not be closely related to any living family of conifer. Its range extended northwards into polar latitudes of Siberia and then contracted northward in the Middle to Late Jurassic, corresponding to the increasing aridity of the region.


title: Jurassic

text: The earliest record of the yew family (Taxaceae) is "Palaeotaxus rediviva", from the Hettangian of Sweden, suggested to be closely related to the living "Austrotaxus", while "Marskea jurassica" from the Middle Jurassic of Yorkshire, England and material from the Callovian–Oxfordian Daohugou Bed in China are thought to be closely related to "Amentotaxus," with the latter material assigned to the modern genus, indicating that Taxaceae had substantially diversified by the end of the Jurassic.


title: Jurassic

text: Podocarpaceae, today largely confined to the Southern Hemisphere, occurred in the Northern Hemisphere during the Jurassic, Examples include "Podocarpophyllum" from the Early to Middle Jurassic of Central Asia and Siberia, "Scarburgia" from the Middle Jurassic of Yorkshire, and "Harrisiocarpus" from the Jurassic of Poland.


title: Jurassic

text: Ginkgoales, of which the sole living species is "Ginkgo biloba", were more diverse during the Jurassic: they were among the most important components of Eurasian Jurassic floras and were adapted to a wide variety of climatic conditions. The earliest representatives of the genus "Ginkgo," represented by ovulate and pollen organs similar to those of the modern species, are known from the Middle Jurassic in the Northern Hemisphere. Several other lineages of ginkgoaleans are known from Jurassic rocks, including "Yimaia", "Grenana", "Nagrenia" and "Karkenia". These lineages are associated with "Ginkgo-"like leaves, but are distinguished from living and fossil representatives of "Ginkgo" by having differently arranged reproductive structures. "Umaltolepis," historically thought to be ginkgoalean, and "Vladimaria" from the Jurassic of Asia have strap-shaped ginkgo-like leaves ("Pseudotorellia") with highly distinct reproductive structures with similarities to those of peltasperm and corystosperm seed ferns; these have been placed in the separate order Vladimariales, which may be related to Ginkgoales.


title: Jurassic

text: Bennettitales, having first become widespread during the preceding Triassic, were diverse and abundant members of Jurassic floras across both hemispheres. The foliage of Bennettitales bears strong similarities to those of cycads, to such a degree that they cannot be reliably distinguished on the basis of morphology alone. Leaves of Bennettitales can be distinguished from those of cycads their different arrangement of stomata, and the two groups are not thought to be closely related. Jurassic Bennettitales predominantly belong to the group Williamsoniaceae, which grew as shrubs and small trees. The Williamsoniaceae are thought to have had a divaricate branching habit, similar to that of living "Banksia", and adapted to growing in open habitats with poor soil nutrient conditions. Bennettitales exhibit complex, flower-like reproductive structures some of which are thought to have been pollinated by insects. Several groups of insects that bear long proboscis, including extinct families such as kalligrammatid lacewings and extant ones such as acrocerid flies, are suggested to have been pollinators of bennettitales, feeding on nectar produced by bennettitalean cones.


title: Jurassic

text: Cycads reached their apex of diversity during the Jurassic and Cretaceous Periods. Despite the Mesozoic sometimes being called the "Age of Cycads", cycads are thought to have been a relatively minor component of mid-Mesozoic floras, with the Bennettitales and Nilssoniales, which have cycad-like foliage, being dominant. The Nilssoniales have often been considered cycads or cycad relatives, but have been found to be distinct on chemical grounds, and perhaps more closely allied with Bennettitales."" Cycads are thought to have been mostly confined to tropical and subtropical latitudes throughout their evolutionary history. The relationships of most Mesozoic cycads to living groups are ambiguous. Modern cycads are pollinated by beetles, and such an association is thought to have formed by the Early Jurassic.


title: Jurassic

text: Although there have been several claimed records and phylogenetic stem group age estimates for individual early diverging angiosperm orders, there are no widely accepted Jurassic fossil records of flowering plants, which make up 90% of living plant species, and fossil evidence suggests that the group diversified during the following Cretaceous.


title: Jurassic

text: "Seed ferns" (Pteridospermatophyta) is a collective term to refer to disparate lineages of fern like plants that produce seeds but have uncertain affinities to living seed plant groups. A prominent group of Jurassic seed ferns is the Caytoniales, which reached their zenith during the Jurassic, with widespread records in the Northern Hemisphere, though records in the Southern Hemisphere remain rare. Due to their berry-like seed-bearing capsules, they have often been suggested to have been closely related or perhaps ancestral to flowering plants, but the evidence for this is inconclusive. A variety of other Jurassic seed ferns of uncertain placement are known, including "Pachypteris" from Europe, which has sometimes been allied with the corystosperms.


title: Jurassic

text: Czekanowskiales, also known as Leptostrobales, are a group of seed plants uncertain affinities with persistent heavily dissected leaves borne on deciduous short shoots, subtended by scale-like leaves, known from the Late Triassic (possibly Late Permian) to Cretaceous. They are thought to have had a tree- or shrub-like habit and formed a conspicuous component of Northern Hemisphere Mesozoic temperate and warm-temperate floras. The genus "Phoenicopsis" was widespread in Early-Middle Jurassic floras of Eastern Asia and Siberia.


title: Jurassic

text: The Pentoxylales, a small but clearly distinct group of liana-like seed plants of obscure affinities, first appeared during the Jurassic. Their distribution appears to have been confined to Eastern Gondwana.


title: Jurassic

text: Living families of ferns widespread during the Jurassic include Dipteridaceae, Matoniaceae, Gleicheniaceae, Osmundaceae and Marattiaceae. Polypodiales, which make up 80% of living fern diversity, have no record from the Jurassic and are thought to have diversified in the Cretaceous, though the widespread Jurassic herbaceous fern genus "Coniopteris," historically interpreted as a close relative of tree ferns of the family Dicksoniaceae, has recently been reinterpreted as an early relative of the group.


title: Jurassic

text: The Cyatheales, the group containing most modern tree ferns, appeared during the Late Jurassic, represented by members of the genus "Cyathocaulis", which are suggested to be early members of Cyatheaceae on the basis of cladistic analysis. Only a handful of possible records exist of the Hymenophyllaceae from the Jurassic, including "Hymenophyllites macrosporangiatus" from the Russian Jurassic.


title: Jurassic

text: The oldest remains of modern horsetails of the genus "Equisetum" first appear in the Early Jurassic, represented by "Equisetum dimorphum" from the Early Jurassic of Patagonia and "Equisetum laterale" from the Early to Middle Jurassic of Australia. Silicified remains of "Equisetum thermale" from the Late Jurassic of Argentina exhibit all the morphological characters of modern members of the genus. The estimated split between "Equisetum bogotense" and all other living "Equisetum" is estimated to have occurred no later than the Early Jurassic.


title: Jurassic

text: Quillworts virtually identical to modern species are known from the Jurassic onwards. "Isoetites rolandii" from the Middle Jurassic of Oregon is the earliest known species to represent all major morphological features of modern "Isoetes". More primitive forms such as "Nathorstiana," which retain an elongated stem, persisted into the Early Cretaceous.


title: Jurassic

text: The moss "Kulindobryum" from the Middle Jurassic of Russia, which was found associated with dinosaur bones, is thought to be related to the Splachnaceae, which grow on animal caracasses. "Bryokhutuliinia" from the same region is thought to be related to Dicranales. "Heinrichsiella" from the Jurassic of Patagonia is thought to belong to either Polytrichaceae or Timmiellaceae.


title: Jurassic

text: The liverwort "Pellites hamiensis" from the Middle Jurassic Xishanyao Formation of China is the oldest record of the family Pelliaceae. "Pallaviciniites sandaolingensis" from the same deposit is thought to belong to the subclass Pallaviciniineae within the Pallaviciniales. "Ricciopsis sandaolingensis", also from the same deposit, is the only Jurassic record of Ricciaceae.


title: Jurassic

text: The Triassic–Jurassic extinction decimated pseudosuchian diversity, with crocodylomorphs, which originated during the early Late Triassic, being the only group of pseudosuchians to survive, with all others, including the herbivorous aetosaurs and carnivorous "rauisuchians" becoming extinct. The morphological diversity of crocodylomorphs during the Early Jurassic was around the same as those of Late Triassic pseudosuchians, but they occupied different areas of morphospace, suggesting that they occupied different ecological niches to their Triassic counterparts and that there was an extensive and rapid radiation of crocodylomorphs during this interval. While living crocodilians are confined to an aquatic ambush predator lifestyle, Jurassic crocodylomorphs exhibited a wide variety of life habits. An unnamed protosuchid known from teeth from the Early Jurassic of Arizona represents the earliest known herbivorous crocodylomorph, an adaptation that appeared several times during the Mesozoic.


title: Jurassic

text: The Thalattosuchia, a clade of predominantly marine crocodylomorphs, first appeared during the Early Jurassic and became a prominent part of marine ecosystems. Within Thalattosuchia, the Metriorhynchidae became highly adapted for life in the open ocean, including the transformation of limbs into flippers, the development of a tail fluke, and smooth, scaleless skin. The morphological diversity of crocodylomorphs during the Early and Middle Jurassic was relatively low compared to that in later time periods and was dominated by terrestrial small-bodied, long-legged sphenosuchians, early crocodyliforms and thalattosuchians. The Neosuchia, a major group of crocodylomorphs, first appeared during the Early to Middle Jurassic. The Neosuchia represents the transition from an ancestrally terrestrial lifestyle to a freshwater aquatic ecology similar to that occupied by modern crocodilians. The timing of the origin of Neosuchia is disputed. The oldest record of Neosuchians has been suggested to be "Calsoyasuchus," from the Early Jurassic of Arizona, which in many analyses has been recovered as the earliest branching member of the neosuchian family Goniopholididae, which radically alters times of diversification for crocodylomorphs. However, this placement has been disputed, with some analyses finding it outside Neosuchia, which would place the oldest records of Neosuchia in the Middle Jurassic. "Razanandrongobe" from the Middle Jurassic of Madagascar has been suggested the represent the oldest record of Notosuchia, a primarily Gondwanan clade of mostly terrestrial crocodylomorphs, otherwise known from the Cretaceous and Cenozoic.


title: Jurassic

text: Stem-group turtles (Testudinata) diversified during the Jurassic. Jurassic stem-turtles belong to two progressively more advanced clades, the Mesochelydia and Perichelydia. It is thought that the ancestral condition for mesochelydians is aquatic, as opposed to terrestrial for testudinates. The two modern groups of turtles (Testudines), Pleurodira and Cryptodira, diverged by the beginning of the Late Jurassic. The oldest known pleurodires, the Platychelyidae, are known from the Late Jurassic of Europe and the Americas, while the oldest unambiguous cryptodire, "Sinaspideretes," an early relative of softshell turtles, is known from the Late Jurassic of China. The Thalassochelydia, a diverse lineage of marine turtles unrelated to modern sea turtles, are known from the Late Jurassic of Europe and South America.


title: Jurassic

text: Rhynchocephalians (the sole living representative being the tuatara) had achieved a global distribution by the beginning of the Jurassic. Rhynchocephalians reached their highest morphological diversity in their evolutionary history during the Jurassic, occupying a wide range of lifestyles, including the aquatic pleurosaurs with long snake-like bodies and reduced limbs, the specialized herbivorous eilenodontines, as well as "Oenosaurus," which had broad tooth plates indicative of durophagy. Rhynchocephalians disappeared from Asia after the Early Jurassic. The last common ancestor of living squamates (which includes lizards and snakes) is estimated to have lived around 190 million years ago during the Early Jurassic, with the major divergences between modern squamate lineages estimated to have occurred during the Early to Middle Jurassic. Squamates first appear in the fossil record during the Middle Jurassic including members of modern clades such as Scincomorpha, though many Jurassic squamates have unclear relationships to living groups. "Eichstaettisaurus" from the Late Jurassic of Germany has been suggested to be an early relative of geckos and displays adaptations for climbing. "Dorsetisaurus" from the Late Jurassic of North America and Europe represents the oldest widely accepted record of Anguimorpha. "Tamaulipasaurus" from Early Jurassic of Mexico and "Marmoretta" from the Middle Jurassic of Britain represents late surviving lepidosauromorphs outside both Rhynchocephalia and Squamata.


title: Jurassic

text: The earliest known remains of Choristodera, a group of freshwater aquatic reptiles with uncertain affinities to other reptile groups, are found in the Middle Jurassic. Only two genera of choristodere are known from the Jurassic. One is the small lizard-like "Cteniogenys", thought to be the most basal known choristodere; it is known from the Middle to Late Jurassic of Europe and Late Jurassic of North America, with similar remains also known from the upper Middle Jurassic of Kyrgyzstan and western Siberia. The other is "Coeruleodraco" from the Late Jurassic of China, which is a more advanced choristodere, though still small and lizard-like in morphology.


title: Jurassic

text: Ichthyosaurs suffered an evolutionary bottleneck during the end-Triassic extinction, with all non-neoichthyosaurians becoming extinct. Ichthyosaurs reached their apex of species diversity during the Early Jurassic, with an array of morphologies including the huge apex predator "Temnodontosaurus" and swordfish-like "Eurhinosaurus," though Early Jurassic ichthyosaurs were significantly less morphologically diverse than their Triassic counterparts. At the Early–Middle Jurassic boundary, between the end of the Toarcian and the beginning of the Bajocian, most lineages of ichythosaur appear to have become extinct, with the first appearance of the Ophthalmosauridae, the clade that would encompass almost all ichthyosaurs from then on, during the early Bajocian. Ophthalmosaurids were diverse by the Late Jurassic, but failed to fill many of the niches that had been occupied by ichthyosaurs during the Early Jurassic.


title: Jurassic

text: Plesiosaurs originated at the end of the Triassic (Rhaetian). By the end of the Triassic, all other sauropterygians, including placodonts and nothosaurs, had become extinct. At least six lineages of plesiosaur crossed the Triassic–Jurassic boundary. Plesiosaurs were already diverse in the earliest Jurassic, with the majority of plesiosaurs in the Hettangian-aged Blue Lias belonging to the Rhomaleosauridae. Early plesiosaurs were generally small-bodied, with body size increasing into the Toarcian. There appears to have been a strong turnover around the Early–Middle Jurassic boundary, with microcleidids and rhomaleosaurids becoming extinct and nearly extinct respectively after the end of the Toarcian with the first appearance of the dominant clade of plesiosaurs of the latter half of the Jurassic, the Cryptoclididae during the Bajocian. The Middle Jurassic saw the evolution of short-necked and large-headed thalassophonean pliosaurs from ancestrally small-headed, long-necked forms"." Some thalassophonean pliosaurs, such as some species of "Pliosaurus", had skulls up to two metres in length with body lengths estimated around 10–12 metres, making them the apex predators of Late Jurassic oceans. Plesiosaurs invaded freshwater environments during the Jurassic, with indeterminate remains of small-bodied pleisosaurs known from freshwater sediments from the Jurassic of China and Australia.


title: Jurassic

text: Pterosaurs first appeared in the Late Triassic. A major radiation of Jurassic pterosaurs is the Rhamphorhynchidae, which first appeared in the late Early Jurassic (Toarcian); they are thought to been piscivorous. Anurognathids, which first appeared in the Middle Jurassic, possessed short heads and densely furred bodies, and are thought to have been insectivores. Derived monofenestratan pterosaurs such as wukongopterids appeared in the late Middle Jurassic. Advanced short-tailed pterodactyloids first appeared at the Middle–Late Jurassic boundary. Jurassic pterodactyloids include the ctenochasmatids, like "Ctenochasma", which have closely spaced needle-like teeth that were presumably used for filter feeding. The bizarre Late Jurassic ctenochasmatoid "Cycnorhamphus" had a jaw with teeth only at the tips, with bent jaws like those of living openbill storks that may have been used to hold and crush hard invertebrates.


title: Jurassic

text: Dinosaurs, which had morphologically diversified in the Late Triassic, experienced a major increase in diversity and abundance during the Early Jurassic in the aftermath of the end-Triassic extinction and the extinction of other reptile groups, becoming the dominant vertebrates in terrestrial ecosystems. "Chilesaurus", a morphologically aberrant herbivorous dinosaur from the Late Jurassic of South America, has uncertain relationships to the three main groups of dinosaurs, having been recovered as a member of all three in different analyses.


title: Jurassic

text: Advanced theropods belonging to Neotheropoda first appeared in the Late Triassic. Basal neotheropods, such as coelophysoids and dilophosaurs, persisted into the Early Jurassic, but became extinct by the Middle Jurassic. The earliest averostrans appear during the Early Jurassic, with the earliest known member of Ceratosauria being "Saltriovenator" from the early Sinemurian (199.3–197.5 million years ago) of Italy. The unusual ceratosaur "Limusaurus" from the Late Jurassic of China had a herbivorous diet, with adults having edentulous beaked jaws, making it the earliest known theropod to have converted from an ancestrally carnivorous diet. The earliest members of the Tetanurae appeared during the late Early Jurassic or early Middle Jurassic. The Megalosauridae represent the oldest radiation of the Tetanurae, first appearing in Europe during the Bajocian. The oldest member of Allosauroidea has been suggested to be "Asfaltovenator" from the Middle Jurassic of South America. Coelurosaurs first appeared during the Middle Jurassic, including early tyrannosaurs such as "Proceratosaurus" from the Bathonian of Britain. Some coelurosaurs from the Late Jurassic of China including "Shishugounykus" and "Haplocheirus" are suggested to represent early alvarezsaurs, however, this has been questioned. Scansoriopterygids, a group of small feathered coelurosaurs with membraneous, bat-like wings for gliding, are known from the Middle to Late Jurassic of China. The oldest record of troodontids is suggested to be "Hesperornithoides" from the Late Jurassic of North America. Tooth remains suggested to represent those of dromaeosaurs are known from the Jurassic, but no body remains are known until the Cretaceous.


title: Jurassic

text: The earliest avialans, which include birds and their ancestors, appear during the Middle to Late Jurassic, definitively represented by "Archaeopteryx" from the Late Jurassic of Germany. Avialans belong to the clade Paraves within Coelurosauria, which also includes dromaeosaurs and troodontids. The Anchiornithidae from the Middle-Late Jurassic of Eurasia have frequently suggested to be avialans, but have also alternatively found as a separate lineage of paravians.


title: Jurassic

text: The earliest definitive ornithischians appear during the Early Jurassic, represented by basal ornithischians like "Lesothosaurus", heterodontosaurids, and early members of Thyreophora. The earliest members of Ankylosauria and Stegosauria appear during the Middle Jurassic. The basal neornithischian "Kulindadromeus" from the Middle Jurassic of Russia indicates that at least some ornithischians were covered in protofeathers. The earliest members of Ankylopollexia, which become prominent in the Cretaceous, appeared during the Late Jurassic, represented by bipedal forms such as "Camptosaurus". Ceratopsians first appeared in the Late Jurassic of China, represented by members of Chaoyangsauridae.


title: Jurassic

text: Sauropods became the dominant large herbivores in terrestrial ecosystems during the Jurassic. Some Jurassic sauropods reached gigantic sizes, becoming the largest organisms to have ever lived on land.


title: Jurassic

text: Basal bipedal sauropodomorphs, such as massospondylids, continued to exist into the Early Jurassic, but became extinct by the beginning of the Middle Jurassic. Quadrupedal sauropomorphs appeared during the Late Triassic. The quadrupedal "Ledumahadi" from the earliest Jurassic of South Africa reached an estimated weight of 12 tons, far in excess of other known basal sauropodomorphs. Gravisaurian sauropods first appeared during the Early Jurassic, with the oldest definitive record being "Vulcanodon" from Zimbabwe, likely of Sinemurian age. Eusauropods first appeared during the late Early Jurassic (Toarcian) and diversified during the Middle Jurassic; these included cetiosaurids, turiasaurs, and mamenchisaurs. Neosauropods such as macronarians and diplodocoids first appeared during the Middle Jurassic, before becoming abundant and globally distributed during the Late Jurassic.


title: Jurassic

text: The diversity of temnospondyls had progressively declined through the Late Triassic, with only brachyopoids surviving into the Jurassic and beyond. Members of the family Brachyopidae are known from Jurassic deposits in Asia, while the chigutisaurid "Siderops" is known from the Early Jurassic of Australia. Modern lissamphibians began to diversify during the Jurassic. The Early Jurassic "Prosalirus" thought to represent the first frog relative with a morphology capable of hopping like living frogs. Morphologically recognisable stem-frogs like the South American "Notobatrachus" are known from the Middle Jurassic, with modern crown-group frogs like "Enneabatrachus" and "Rhadinosteus" appearing by the Late Jurassic. While the earliest salamander-line amphibians are known from the Triassic, crown group salamanders first appear during the Middle to Late Jurassic in Eurasia, alongside stem-group relatives. Many Jurassic stem-group salamanders, such as "Marmorerpeton" and "Kokartus", are thought to have been neotenic. Early representatives of crown group salamanders include "Chunerpeton, Pangerpeton" and "Linglongtriton" from the Middle to Late Jurassic Yanliao Biota of China. These belong to the Cryptobranchoidea, which contains living Asiatic and giant salamanders. "Beiyanerpeton", and "Qinglongtriton" from the same biota are thought to be early members of Salamandroidea, the group which contains all other living salamanders. Salamanders dispersed into North America by the end of the Jurassic, as evidenced by "Iridotriton", found in the Late Jurassic Morrison Formation. The oldest undisputed stem-caecilian is the Early Jurassic "Eocaecilia" from Arizona. The fourth group of lissamphibians, the extinct albanerpetontids, first appeared in the Middle Jurassic, represented by "Anoualerpeton priscus" from the Bathonian of Britain, as well as indeterminate remains from equivalently aged sediments in France and the Anoual Formation of Morocco.


title: Jurassic

text: Mammaliaformes, having originated from cynodonts at the end of the Triassic, diversified extensively during the Jurassic. Important groups of Jurassic Mammaliaformes include Morganucodonta, Docodonta, Eutriconodonta, Dryolestida, Haramiyida and Multituberculata. While most Jurassic mammalaliaformes are solely known from isolated teeth and jaw fragments, exceptionally preserved remains have revealed a variety of lifestyles. The docodontan "Castorocauda" was adapted to aquatic life, similarly to the platypus and otters. Some members of Haramiyida and the eutriconodontan tribe Volaticotherini had a patagium akin to those of flying squirrels, allowing them to glide through the air. The aardvark-like mammal "Fruitafossor", of uncertain taxonomy, was likely a specialist on colonial insects, similarly to living anteaters. Australosphenida, a group of mammals possibly related to monotremes, first appeared in the Middle Jurassic of Gondwana. Therian mammals, represented today by living placentals and marsupials, appear during the early Late Jurassic, represented by "Juramaia," a eutherian mammal closer to the ancestry of placentals than marsupials. "Juramaia" is much more advanced than expected for its age, as other therian mammals are not known until the Early Cretaceous. Two groups of non-mammalian cynodonts persisted beyond the end of the Triassic. The insectiviorous Tritheledontidae has a few records from the Early Jurassic. The Tritylodontidae, a herbiviorous group of cynodonts that first appeared during the Rhaetian, has abundant records from the Jurassic, overwhelmingly from the Northern Hemisphere.


title: Jurassic

text: The last known species of conodont, a class of jawless fish whose hard, tooth-like elements are key index fossils, finally became extinct during the earliest Jurassic after over 300 million years of evolutionary history, with an asynchronous extinction occurring first in the Tethys and eastern Panthalassa and survivors persisting into the earliest Hettangian of Hungary and central Panthalassa. End-Triassic conodonts were represented by only a handful of species and had been progressively declining through the Middle and Late Triassic.


title: Jurassic

text: Lungfish (Dipnoi) were present in freshwater environments of both hemispheres during the Jurassic. Genera include "Ceratodus" and "Ptychoceratodus", which are more closely related to living South American and African lungfish than Queensland lungfish, and "Ferganoceratodus" from the Jurassic of Asia, which is not closely related to either group of living lungfish. Mawsoniids, a marine and freshwater/brackish group of coelacanths, which first appeared in North America during the Triassic, expanded into Europe and South America by the end of the Jurassic. The marine Latimeriidae, which contains the living coelacanths of the genus "Latimeria", were also present in the Jurassic, having originated in the Triassic.


title: Jurassic

text: Ray-finned fish (Actinopterygii) were major components of Jurassic freshwater and marine ecosystems. Archaic "palaeoniscoid" fish, which were common in both marine and freshwater habitats during the preceding Triassic declined during the Jurassic, being largely replaced by more derived actinopterygian lineages. The oldest known Acipenseriformes, the group that contains living sturgeon and paddlefish, are from the Early Jurassic. Amiiform fish (which today only includes the bowfin) first appeared during the Early Jurassic, represented by "Caturus" from the Pliensbachian of Britain; after their appearance in the western Tethys, they expanded to Africa, North America and Southeast and East Asia by the end of the Jurassic. Pycnodontiformes, which first appeared in the western Tethys during the Late Triassic, expanded to South America and Southeast Asia by the end of the Jurassic, having a high diversity in Europe during the Late Jurassic. During the Jurassic, the Ginglymodi, the only living representatives being gars (Lepisosteidae) were diverse in both freshwater and marine environments. The oldest known representatives of anatomically modern gars appeared during the Upper Jurassic. Stem-group teleosts, which make up over 99% of living Actinopterygii, had first appeared during the Triassic in the western Tethys; they underwent a major diversification beginning in the Late Jurassic, with early representatives of modern teleost clades such as Elopomorpha and Osteoglossoidei appearing during this time. The Pachycormiformes, a group of marine stem-teleosts, first appeared in the Early Jurassic and included both tuna-like predatory and filter-feeding forms, the latter included the largest bony fish known to have existed: "Leedsichthys", with an estimated maximum length of over 15 metres, known from the late Middle to Late Jurassic.


title: Jurassic

text: During the Early Jurassic, the shark-like hybodonts, which represented the dominant group of chondrichthyians during the preceding Triassic, were common in both marine and freshwater settings; however, by the Late Jurassic, hybodonts had become minor components of most marine communities, having been largely replaced by modern neoselachians, but remained common in freshwater and restricted marine environments. The Neoselachii, which contains all living sharks and rays, radiated beginning in the Early Jurassic. The oldest known ray (Batoidea) is "Antiquaobatis" from the Pliensbachian of Germany. Jurassic batoids known from complete remains retain a conservative, guitarfish-like morphology. The oldest known Hexanchiformes and carpet sharks (Orectolobiformes) are from the Early Jurassic (Pliensbachian & Toarcian, respectively) of Europe. The oldest known members of the Heterodontiformes, the only living member of which is the bullhead shark ("Heterodontus"), first appeared in the Early Jurassic, with representatives of the living genus appearing during the Late Jurassic. The oldest known mackerel sharks (Lamniformes) are from the Middle Jurassic, represented by the genus "Palaeocarcharias", which has an orectolobiform-like body but shares key similarities in tooth histology with lamniformes, including the absence of orthodentine. The oldest record of angelsharks (Squatiniformes) is "Pseudorhina" from the Late Jurassic (Oxfordian–Tithonian) of Europe, which already has a bodyform similar to living members of the order. The oldest known remains of Carcharhiniformes, the largest order of living sharks, first appear in the late Middle Jurassic (Bathonian) of the western Tethys (England and Morocco). Known dental and exceptionally preserved body remains of Jurassic Carchariniformes are similar to those of living catsharks. Synechodontiformes, an extinct group of sharks closely related to Neoselachii, were also widespread during the Jurassic. The oldest remains of modern chimaeras are from the Early Jurassic of Europe, with members of the living family Callorhinchidae appearing during the Middle Jurassic. Unlike living chimaeras, these were found in shallow water settings. The closely related "Squaloraja" and myriacanthoids are also known from the Jurassic of Europe.


title: Jurassic

text: There appears to have been no major extinction of insects at the Triassic–Jurassic boundary. Many important insect fossil localities are known from the Jurassic of Eurasia, the most important being the Karabastau Formation of Kazakhstan and the various Yanliao Biota deposits in Inner Mongolia, China, such as the Daohugou Bed, dating to the Callovian–Oxfordian. The diversity of insects stagnated throughout the Early and Middle Jurassic, but during the latter third of the Jurassic origination rates increased substantially while extinction rates remained flat. The increasing diversity of insects in the Middle–Late Jurassic corresponds with a substantial increase in the diversity of insect mouthparts. The Middle to Late Jurassic was a time of major diversification for beetles. Weevils first appear in the fossil record during the Middle to Late Jurassic, but are suspected to have originated during the Late Triassic to Early Jurassic. The oldest known lepidopterans (the group containing butterflies and moths) are known from the Triassic–Jurassic boundary, with wing scales belonging to the suborder Glossata and Micropterigidae-grade moths from the deposits of this age in Germany. Modern representatives of both dragonflies and damselflies also first appeared during the Jurassic. Although modern representatives are not known until the Cenozoic, ectoparasitic insects thought to represent primitive fleas, belonging to the family Pseudopulicidae, are known from the Middle Jurassic of Asia. These insects are substantially different from modern fleas, lacking the specialised morphology of the latter and being larger. Parasitoid wasps (Apocrita) first appeared during the Early Jurassic and subsequently became widespread, reshaping terrestrial food webs. The Jurassic saw also saw the first appearances of several other groups of insects, including Phasmatodea (stick insects), Mantophasmatidae, Embioptera (webspinners), and Raphidioptera (snakeflies).


title: Jurassic

text: Only a handful of records of mites are known from the Jurassic, including "Jureremus", an oribatid mite belonging to the family Cymbaeremaeidae known from the Late Jurassic of Britain and Russia, and a member of the still living orbatid genus "Hydrozetes" from the Early Jurassic of Sweden. Spiders diversified through the Jurassic. The Early Jurassic "Seppo koponeni" may represent a stem group to Palpimanoidea. "Eoplectreurys" from the Middle Jurassic of China is considered a stem lineage of Synspermiata. The oldest member of the family Archaeidae, "Patarchaea", is known from the Middle Jurassic of China. "Mongolarachne" from the Middle Jurassic of China is among the largest known fossil spiders, with legs over 5 centimetres long. The only scorpion known from the Jurassic is "Liassoscorpionides" from the Early Jurassic of Germany, of uncertain placement. Eupnoi harvestmen (Opiliones) are known from the Middle Jurassic of China, including members of the family Sclerosomatidae.


title: Jurassic

text: During the end-Triassic extinction, 46%–72% of all marine genera became extinct. The effects of the end Triassic extinction were greatest at tropical latitudes and were more severe in Panthalassa than the Tethys or Boreal oceans. Tropical reef ecosystems collapsed during the event, and would not fully recover until much later in the Jurassic. Sessile filter feeders and photosymbiotic organisms were among most severely affected.


title: Jurassic

text: Having declined at the Triassic–Jurassic boundary, reefs substantially expanded during the Late Jurassic, including both sponge reefs and scleractinian coral reefs. Late Jurassic reefs were similar in form to modern reefs but had more microbial carbonates and hypercalcified sponges, and had weak biogenic binding. Reefs sharply declined at the close of the Jurassic, which caused an associated drop in diversity in decapod crustaceans. The earliest planktonic foraminifera, which constitute the suborder Globigerinina, are known from the late Early Jurassic (mid-Toarcian) of the western Tethys, expanding across the whole Tethys by the Middle Jurassic and becoming globally distributed in tropical latitudes by the Late Jurassic. Coccolithophores and dinoflagellates, which had first appeared during the Triassic, radiated during the Early to Middle Jurassic, becoming prominent members of the phytoplankton. Microconchid tube worms, the last remaining order of Tentaculita, a group of animals of uncertain affinities that were convergent on "Spirorbis" tube worms, were rare after the Triassic and had become reduced to the single genus "Punctaconchus," which became extinct in the late Bathonian. The oldest known diatom is from Late Jurassic–aged amber from Thailand, assigned to the living genus "Hemiaulus."


title: Jurassic

text: Crinoids diversified throughout the Jurassic, reaching their peak Mesozoic diversity during the Late Jurassic, primarily due to the radiation of sessile forms belonging to the orders Cyrtocrinida and Millericrinida. Echinoids (sea urchins) underwent substantial diversification beginning in the Early Jurassic, primarily driven by the radiation of irregular (asymmetrical) forms, which were adapting to deposit feeding. Rates of diversification sharply dropped during the Late Jurassic.


title: Jurassic

text: The Jurassic was a significant time for the evolution of decapods. The first true crabs (Brachyura) are known from the Early Jurassic, with the earliest being "Eocarcinus praecursor" from the early Pliensbachian of England, which lacked the crab-like morphology (carcinisation) of modern crabs, and "Eoprosopon klugi" from the late Pliensbachian of Germany, which may belong to the living family Homolodromiidae. Most Jurassic crabs are known only from carapace pieces, which makes it difficult to determine their relationships. While rare in the Early and Middle Jurassic, crabs became abundant during the Late Jurassic as they expanded from their ancestral silty sea floor habitat into hard substrate habitats like reefs, with crevices in reefs providing refuge from predators. Hermit crabs also first appeared during the Jurassic, with the earliest known being "Schobertella hoelderi" from the late Hettangian of Germany. Early hermit crabs are associated with ammonite shells rather than those of gastropods. Glypheids, which today are only known from two species, reached their peak diversity during the Jurassic, with around 150 species out of a total fossil record of 250 known from the period. Jurassic barnacles were of low diversity compared to present, but several important evolutionary innovations are known, including the first appearances of calcite shelled forms and species with an epiplanktonic mode of life.


title: Jurassic

text: Brachiopod diversity declined during the Triassic–Jurassic extinction. Spire-bearing groups (Spiriferinida and Athyridida) declined at the Triassic–Jurassic boundary and did not recover their biodiversity, becoming extinct in the TOAE. Rhynchonellida and Terebratulida also declined during the Triassic–Jurassic extinction but rebounded during the Early Jurassic; neither clade underwent much morphological variation. Brachiopods substantially declined in the Late Jurassic; the causes are poorly understood. Proposed reasons include increased predation, competition with bivalves, enhanced bioturbation or increased grazing pressure.


title: Jurassic

text: Like the preceding Triassic, bryozoan diversity was relatively low compared to the Paleozoic. The vast majority of Jurassic bryozoans are members of Cyclostomatida, which experienced a radiation during the Middle Jurassic, with all Jurassic representatives belonging to the suborders Tubuliporina and Cerioporina. Cheilostomata, the dominant group of modern bryozoans, first appeared during the Late Jurassic.


title: Jurassic

text: The end-Triassic extinction had a severe impact on bivalve diversity, though it had little impact on bivalve ecological diversity. The extinction was selective, having less of an impact on deep burrowers, but there is no evidence of a differential impact between surface-living (epifaunal) and burrowing (infaunal) bivalves. Bivalve family level diversity after the Early Jurassic was static, though genus diversity experienced a gradual increase throughout the period. Rudists, the dominant reef-building organisms of the Cretaceous, first appeared in the Late Jurassic (mid-Oxfordian) in the northern margin of the western Tethys, expanding to the eastern Tethys by the end of the Jurassic.


title: Jurassic

text: Ammonites were devastated by the end-Triassic extinction, with only a handful of genera belonging to the family Psiloceratidae of the suborder Phylloceratina surviving and becoming ancestral to all later Jurassic and Cretaceous ammonites. Ammonites explosively diversified during the Early Jurassic, with the orders Psiloceratina, Ammonitina, Lytoceratina, Haploceratina, Perisphinctina and Ancyloceratina all appearing during the Jurassic. Ammonite faunas during the Jurassic were regional, being divided into around 20 distinguishable provinces and subprovinces in two realms, the northern high latitude Pan-Boreal realm, consisting of the Arctic, northern Panthalassa and northern Atlantic regions, and the equatorial–southern Pan-Tethyan realm, which included the Tethys and most of Panthalassa.


title: Jurassic

text: The oldest definitive records of the squid-like belemnites are from the earliest Jurassic (Hettangian–Sinemurian) of Europe and Japan; they expanded worldwide during the Jurassic. Belemnites were shallow-water dwellers, inhabiting the upper 200 metres of the water column on the continental shelves and in the littoral zone. They were key components of Jurassic ecosystems, both as predators and prey, as evidenced by the abundance of belemnite guards in Jurassic rocks.


title: Jurassic

text: The earliest vampyromorphs, of which the only living member is the vampire squid, first appeared during the Early Jurassic. The earliest octopuses appeared during the Middle Jurassic, having split from their closest living relatives, the vampyromorphs, during the Triassic to Early Jurassic. All Jurassic octopuses are solely known from the hard gladius. Octopuses likely originated from bottom-dwelling (benthic) ancestors which lived in shallow environments. "Proteroctopus" from the late Middle Jurassic La Voulte-sur-Rhône lagerstätte, previously interpreted as an early octopus, is now thought to be a basal taxon outside the clade containing vampyromorphs and octopuses.


title: Rattlesnake

text: Rattlesnakes are venomous snakes that form the genera "Crotalus" and "Sistrurus" of the subfamily Crotalinae (the pit vipers). All rattlesnakes are vipers. Rattlesnakes are predators that live in a wide array of habitats, hunting small animals such as birds and rodents.


title: Rattlesnake

text: Rattlesnakes receive their name from the rattle located at the end of their tails, which makes a loud rattling noise when vibrated that deters predators or serves as a warning to passers-by. Rattlesnakes are the leading contributor to snakebite injuries in North America, but rarely bite unless provoked or threatened; if treated promptly, the bites are seldom fatal.


title: Rattlesnake

text: The 36 known species of rattlesnakes have between 65 and 70 subspecies, all native to the Americas, ranging from British Columbia through Ontario in southern Canada, to central Argentina. The largest rattlesnake, the eastern diamondback, can measure up to in length.


title: Rattlesnake

text: Rattlesnakes are preyed upon by hawks, weasels, king snakes, and a variety of other species. Rattlesnakes are heavily preyed upon as neonates, while they are still weak and immature. Large numbers of rattlesnakes are killed by humans. Rattlesnake populations in many areas are severely threatened by habitat destruction, poaching, and extermination campaigns.


title: Rattlesnake

text: The scientific name "Crotalus" is derived from the Greek κρόταλον, meaning "castanet". The name "Sistrurus" is the Latinized form of the Greek word for "tail rattler" (Σείστρουρος, "seistrouros") and shares its root with the ancient Egyptian musical instrument the sistrum, a type of rattle.


title: Rattlesnake

text: Rattlesnakes are native to the Americas from southern Canada to central Argentina, with the majority of species inhabiting arid regions. The large majority of species live in the American Southwest and Mexico. Four species may be found east of the Mississippi River, and two in South America. In the United States, the state with the most types of rattlesnakes is Arizona, with 13.


title: Rattlesnake

text: Rattlesnakes are found in almost every habitat type capable of supporting terrestrial ectothermic vertebrates, but individual species may have extremely specific habitat requirements, living where certain plant associations occur or within a narrow range of elevations. Most species live near open, rocky areas. Rocks offer them cover from predators, plentiful prey (e.g. rodents, lizards, insects, etc. that live amidst the rocks), and open basking areas. However, rattlesnakes can also be found in a wide variety of other habitats, including prairies, marshes, deserts, and forests. Rattlesnakes prefer a temperature range between 80 and 90 °F (26 and 32 °C), but can survive temperatures below freezing, recovering from brief exposure to temperatures as low as 4 °F (−16 °C), and surviving for several days in temperatures as low as 37 °F (3 °C).


title: Rattlesnake

text: The most probable ancestral area of rattlesnakes is the Sierra Madre Occidental region in Mexico. The most probable vegetation or habitat of the ancestral area appears to be pine-oak forests.


title: Rattlesnake

text: Rattlesnakes typically consume mice, rats, rabbits, squirrels, small birds, and other small animals. They lie in wait for their prey, or hunt for it in holes. The rattlesnake’s defence and hunting mechanisms are bound to its physiology and its environment. More importantly environmental temperature can influence the ability of ectotherms. The prey is killed quickly with a venomous bite as opposed to constriction. If the bitten prey moves away before dying, the rattlesnake can follow it by its scent. When it locates the fallen prey, it checks for signs of life by prodding with its snout, flicking its tongue, and using its sense of smell. Once the prey has become incapacitated, the rattlesnake locates its head by odors emitted from the mouth. The prey is then ingested head first, which allows wings and limbs to fold at the joints in a manner that minimizes the girth of the meal. The gastric fluids of rattlesnakes are extremely powerful, allowing for the digestion of flesh and bone. Optimal digestion occurs when the snake maintains a body temperature between 80 and 85 °F (25 and 29 °C). If the prey is small, the rattlesnake often continues hunting. If the meal was adequate, the snake finds a warm, safe location in which to coil up and rest until the prey is digested. Feeding habits play an important ecological role by limiting the size of rodent populations, which prevents crop damage and stabilizes ecosystems.


title: Rattlesnake

text: Rattlesnakes are believed to require at least their own body weight in water annually to remain hydrated. The method by which they drink depends on the water source. In larger bodies of water (streams, ponds, etc.), they submerge their heads and ingest water by opening and closing their jaws, which sucks in water. If drinking dew or small puddles, they sip the liquid either by capillary action or by flattening and flooding their lower jaws.


title: Rattlesnake

text: Newborn rattlesnakes are heavily preyed upon by a variety of species, including cats, ravens, crows, roadrunners, raccoons, opossums, skunks, coyotes, weasels, whipsnakes, kingsnakes, and racers. Young of the smaller crotaline species are frequently killed and eaten by small predatory birds, such as jays, kingfishers, and shrikes. Some species of ants in the genus "Formica" are known to prey upon neonates, and "Solenopsis invicta" (fire ants) likely do, as well. On occasion, hungry adult rattlesnakes cannibalize neonates. The small proportion (often as few as 20%) of rattlesnakes that make it to their second year are heavily preyed upon by a variety of larger predators, including coyotes, eagles, hawks, owls, falcons, feral pigs, badgers, indigo snakes, and kingsnakes.


title: Rattlesnake

text: The common kingsnake ("Lampropeltis getula"), a constrictor, is immune to the venom of rattlesnakes and other vipers, and rattlesnakes form part of its natural diet. Rattlesnakes sense kingsnakes' presence by their odor. When they realize a kingsnake is nearby, they begin enacting a set of defensive postures known as "body bridging". Unlike its normal erect and coiled defensive-striking posture, the rattlesnake keeps its head low to the ground in an attempt to prevent the kingsnake from gaining a hold on it (the head being the first part of the rattlesnake to be ingested). The rattlesnake jerks its body about, while bridging its back upwards, forming an elevated coil that faces the kingsnake. The elevated coil is used to strike the attacker, and is also used to shield the head from the kingsnake.


title: Rattlesnake

text: Like all pit vipers, rattlesnakes have two organs that can sense radiation; their eyes and a set of heat-sensing "pits" on their faces that enable them to locate prey and move towards it, based on the prey's thermal radiation signature. These pits have a relatively short effective range of about 1 ft, but give the rattlesnake a distinctive advantage in hunting for warm-blooded creatures at night.


title: Rattlesnake

text: Aside from their eyes, rattlesnakes are able to detect thermal radiation emitted by warm-blooded organisms in their environment. Functioning optically like a pinhole camera eye, thermal radiation in the form of infrared light passes through the opening of the pit and strikes the pit membrane located in the back wall, warming this part of the organ. Due to the high density of heat-sensitive receptors innervating this membrane, the rattlesnake can detect temperature changes of 0.003 °C or less in its immediate surroundings. Infrared cues from these receptors are transmitted to the brain by the trigeminal nerve, where they are used to create thermal maps of the snake's surroundings. Due to the small sizes of the pit openings, typically these thermal images are low in resolution and contrast. Nevertheless, rattlesnakes superimpose visual images created from information from the eyes with these thermal images from the pit organs to more accurately visualize their surroundings in low levels of light. Research conducted recently on the molecular mechanism of this ability suggests the temperature sensitivity of these pit organs is closely linked to the activity of transient receptor potential ankyrin 1, a temperature-sensitive ion channel saturated in the pit membrane.


title: Rattlesnake

text: Rattlesnake eyes, which contain many rod cells, are well adapted to nocturnal use. Rattlesnakes, though, are not exclusively nocturnal, and their vision is more acute during daylight conditions. Rattlesnakes also possess cone cells, which means they are capable of some form of color vision. The rattlesnake eye lacks a fovea, making vision of sharply defined images impossible. Instead, they mostly rely on the perception of movement. Rattlesnake eyes are capable of horizontal rotation, but they do not appear to move their eyeballs to follow moving objects.


title: Rattlesnake

text: Rattlesnakes have an exceptionally keen sense of smell. They can sense olfactory stimuli both through their nostrils and by flicking their tongues, which carry scent-bearing particles to the Jacobson's organs in the roof of their mouths.


title: Rattlesnake

text: Like all snakes, rattlesnakes lack external ear openings, and the structures of their middle ear are not as highly specialized as those of other vertebrates, such as mammals. Thus, their sense of hearing is not very effective, but they are capable of sensing vibrations in the ground, passed by the skeleton to the auditory nerve.