Misplaced Pages

#68931

123-458: Perophthalma is a very small butterfly genus in the family Riodinidae . The genus comprises only two species , both found only in Central and South America . They are commonly called eyemarks , alluding to the eyespot on the wings. This Riodinidae -related article is a stub . You can help Misplaced Pages by expanding it . Butterfly Butterflies are winged insects from

246-637: A diapause (resting) stage, and the hatching may take place only in spring. Some temperate region butterflies, such as the Camberwell beauty , lay their eggs in the spring and have them hatch in the summer. Butterfly larvae, or caterpillars, consume plant leaves and spend practically all of their time searching for and eating food. Although most caterpillars are herbivorous, a few species are predators : Spalgis epius eats scale insects , while lycaenids such as Liphyra brassolis are myrmecophilous , eating ant larvae. Some larvae, especially those of

369-711: 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. At the beginning of the Jurassic, all of

492-493: A butterfly cannot fly until the wings are unfolded. A newly emerged butterfly needs to spend some time inflating its wings with hemolymph and letting them dry, during which time it is extremely vulnerable to predators. The colourful patterns on many butterfly wings tell potential predators that they are toxic. Hence, the genetic basis of wing pattern formation can illuminate both the evolution of butterflies as well as their developmental biology . The colour of butterfly wings

615-570: A butterfly through metamorphosis has held great appeal to mankind. To transform from the miniature wings visible on the outside of the pupa into large structures usable for flight, the pupal wings undergo rapid mitosis and absorb a great deal of nutrients. If one wing is surgically removed early on, the other three will grow to a larger size. In the pupa, the wing forms a structure that becomes compressed from top to bottom and pleated from proximal to distal ends as it grows, so that it can rapidly be unfolded to its full adult size. Several boundaries seen in

738-417: A common family. In some species, such as the great spangled fritillary , the eggs are deposited close to but not on the food plant. This most likely happens when the egg overwinters before hatching and where the host plant loses its leaves in winter, as do violets in this example. The egg stage lasts a few weeks in most butterflies, but eggs laid close to winter, especially in temperate regions, go through

861-499: 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. Araucarian conifers have their first unambiguous records during the Early Jurassic, and members of the modern genus Araucaria were widespread across both hemispheres by

984-576: A few butterflies (e.g., harvesters ) eat harmful insects, and a few are predators of ants , while others live as mutualists in association with ants. Culturally, butterflies are a popular motif in the visual and literary arts. The Smithsonian Institution says "butterflies are certainly one of the most appealing creatures in nature". The Oxford English Dictionary derives the word straightforwardly from Old English butorflēoge , butter-fly; similar names in Old Dutch and Old High German show that

1107-444: A few species. Some butterflies have organs of hearing and some species make stridulatory and clicking sounds. Many species of butterfly maintain territories and actively chase other species or individuals that may stray into them. Some species will bask or perch on chosen perches. The flight styles of butterflies are often characteristic and some species have courtship flight displays. Butterflies can only fly when their temperature

1230-606: A hard-ridged outer layer of shell, called the chorion . This is lined with a thin coating of wax which prevents the egg from drying out before the larva has had time to fully develop. Each egg contains a number of tiny funnel-shaped openings at one end, called micropyles ; the purpose of these holes is to allow sperm to enter and fertilize the egg. Butterfly eggs vary greatly in size and shape between species, but are usually upright and finely sculptured. Some species lay eggs singly, others in batches. Many females produce between one hundred and two hundred eggs. Butterfly eggs are fixed to

1353-647: 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

SECTION 10

#1732773041069

1476-508: A leaf before eggs are laid on it. Many butterflies use chemical signals, pheromones ; some have specialized scent scales ( androconia ) or other structures ( coremata or "hair pencils" in the Danaidae). Vision is well developed in butterflies and most species are sensitive to the ultraviolet spectrum. Many species show sexual dimorphism in the patterns of UV reflective patches. Colour vision may be widespread but has been demonstrated in only

1599-416: A leaf with a special glue which hardens rapidly. As it hardens it contracts, deforming the shape of the egg. This glue is easily seen surrounding the base of every egg forming a meniscus. The nature of the glue has been little researched but in the case of Pieris brassicae , it begins as a pale yellow granular secretion containing acidophilic proteins. This is viscous and darkens when exposed to air, becoming

1722-547: A longer lifespan of several months as adults. The thorax of the butterfly is devoted to locomotion. Each of the three thoracic segments has two legs (among nymphalids , the first pair is reduced and the insects walk on four legs). The second and third segments of the thorax bear the wings. The leading edges of the forewings have thick veins to strengthen them, and the hindwings are smaller and more rounded and have fewer stiffening veins. The forewings and hindwings are not hooked together ( as they are in moths ) but are coordinated by

1845-452: A necessity for their successful establishment. Many butterflies, such as the painted lady , monarch, and several danaine migrate for long distances. These migrations take place over a number of generations and no single individual completes the whole trip. The eastern North American population of monarchs can travel thousands of miles south-west to overwintering sites in Mexico . There is

1968-453: 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. 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

2091-658: A reverse migration in the spring. It has recently been shown that the British painted lady undertakes a 9,000-mile round trip in a series of steps by up to six successive generations, from tropical Africa to the Arctic Circle — almost double the length of the famous migrations undertaken by monarch. Spectacular large-scale migrations associated with the monsoon are seen in peninsular India. Migrations have been studied in more recent times using wing tags and also using stable hydrogen isotopes . Butterflies navigate using

2214-412: A segmented palp. Adjoining these is the labium-hypopharynx which houses a tubular spinneret which is able to extrude silk. Caterpillars such as those in the genus Calpodes (family Hesperiidae) have a specialized tracheal system on the 8th segment that function as a primitive lung. Butterfly caterpillars have three pairs of true legs on the thoracic segments and up to six pairs of prolegs arising from

2337-435: A silken girdle may be spun to keep the pupa in a head-up position. Most of the tissues and cells of the larva are broken down inside the pupa, as the constituent material is rebuilt into the imago. The structure of the transforming insect is visible from the exterior, with the wings folded flat on the ventral surface and the two halves of the proboscis, with the antennae and the legs between them. The pupal transformation into

2460-410: A time-compensated sun compass. They can see polarized light and therefore orient even in cloudy conditions. The polarized light near the ultraviolet spectrum appears to be particularly important. Many migratory butterflies live in semi-arid areas where breeding seasons are short. The life histories of their host plants also influence butterfly behaviour. Butterflies in their adult stage can live from

2583-541: A total of about 20,000 species. Traditionally, butterflies have been divided into the superfamilies Papilionoidea and the moth-like Hedyloidea . Recent work has discovered that Hedylidae, the only family within Hedyloidea, is nested within the Papilionoidea, meaning that Papilionoidea would be synonymous with Rhopalocera. The relationships between the rest of the 6 families are extremely well resolved, which

SECTION 20

#1732773041069

2706-470: A trend towards multivoltinism . Courtship is often aerial and often involves pheromones . Butterflies then land on the ground or on a perch to mate. Copulation takes place tail-to-tail and may last from minutes to hours. Simple photoreceptor cells located at the genitals are important for this and other adult behaviours. The male passes a spermatophore to the female; to reduce sperm competition, he may cover her with his scent, or in some species such as

2829-486: A tubular proboscis which is curled up at rest and expanded when needed to feed. The first and second maxillae bear palps which function as sensory organs. Some species have a reduced proboscis or maxillary palps and do not feed as adults. Many Heliconius butterflies also use their proboscis to feed on pollen; in these species only 20% of the amino acids used in reproduction come from larval feeding, which allow them to develop more quickly as caterpillars, and gives them

2952-437: A water-insoluble, rubbery material which soon sets solid. Butterflies in the genus Agathymus do not fix their eggs to a leaf; instead, the newly laid eggs fall to the base of the plant. Eggs are almost invariably laid on plants. Each species of butterfly has its own host plant range and while some species of butterfly are restricted to just one species of plant, others use a range of plant species, often including members of

3075-422: A week to nearly a year depending on the species. Many species have long larval life stages while others can remain dormant in their pupal or egg stages and thereby survive winters. The Melissa Arctic ( Oeneis melissa ) overwinters twice as a caterpillar. Butterflies may have one or more broods per year. The number of generations per year varies from temperate to tropical regions with tropical regions showing

3198-492: 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

3321-450: Is above 27 °C (81 °F); when it is cool, they can position themselves to expose the underside of the wings to the sunlight to heat themselves up. If their body temperature reaches 40 °C (104 °F), they can orientate themselves with the folded wings edgewise to the sun. Basking is an activity which is more common in the cooler hours of the morning. Some species have evolved dark wingbases to help in gathering more heat and this

3444-458: Is derived from tiny structures called scales, each of which have their own pigments . In Heliconius butterflies, there are three types of scales: yellow/white, black, and red/orange/brown scales. Some mechanism of wing pattern formation are now being solved using genetic techniques. For instance, a gene called cortex determines the colour of scales: deleting cortex turned black and red scales yellow. Mutations, e.g. transposon insertions of

3567-494: 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. Stages can be defined globally or regionally. For global stratigraphic correlation,

3690-403: Is especially evident in alpine forms. As in many other insects, the lift generated by butterflies is more than can be accounted for by steady-state, non-transitory aerodynamics . Studies using Vanessa atalanta in a wind tunnel show that they use a wide variety of aerodynamic mechanisms to generate force. These include wake capture , vortices at the wing edge, rotational mechanisms and

3813-410: Is extruded and inserted into the female's vagina. A spermatophore is deposited in the female, following which the sperm make their way to a seminal receptacle where they are stored for later use. In both sexes, the genitalia are adorned with various spines, teeth, scales and bristles, which act to prevent the butterfly from mating with an insect of another species. After it emerges from its pupal stage,

Perophthalma - Misplaced Pages Continue

3936-565: Is followed by the Kimmeridgian Warm Interval (KWI) between 164 and 150 million years ago. Based on fossil wood distribution, this was one of the wettest intervals of the Jurassic. The Pangaean 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. A prominent drop in temperatures occurred during

4059-470: Is fourth order, with a periodicity of approximately 410,000 years. 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

4182-451: Is good, especially in some species in the blue/violet range. The antennae are composed of many segments and have clubbed tips (unlike moths that have tapering or feathery antennae). The sensory receptors are concentrated in the tips and can detect odours. Taste receptors are located on the palps and on the feet. The mouthparts are adapted to sucking and the mandibles are usually reduced in size or absent. The first maxillae are elongated into

4305-475: 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. The TOAE is often attributed to the eruption of the Karoo-Ferrar large igneous provinces and the associated increase of carbon dioxide concentration in

4428-577: 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

4551-581: Is native to the Americas, but in the nineteenth century or before, spread across the world, and is now found in Australia, New Zealand, other parts of Oceania, and the Iberian Peninsula . It is not clear how it dispersed; adults may have been blown by the wind or larvae or pupae may have been accidentally transported by humans, but the presence of suitable host plants in their new environment was

4674-465: Is restricted to the males, and studies have suggested that the nutrients collected may be provided as a nuptial gift , along with the spermatophore, during mating. In hilltopping , males of some species seek hilltops and ridge tops, which they patrol in search for females. Since it usually occurs in species with low population density, it is assumed these landscape points are used as meeting places to find mates. Butterflies use their antennae to sense

4797-698: Is summarized in the below cladogram. Papilionidae [REDACTED] Hedylidae [REDACTED] Hesperiidae [REDACTED] Pieridae [REDACTED] Nymphalidae [REDACTED] Lycaenidae [REDACTED] Riodinidae [REDACTED] Butterfly adults are characterized by their four scale-covered wings, which give the Lepidoptera their name ( Ancient Greek λεπίς lepís, scale + πτερόν pterón, wing). These scales give butterfly wings their colour: they are pigmented with melanins that give them blacks and browns, as well as uric acid derivatives and flavones that give them yellows, but many of

4920-405: Is taken up by the gut, but there may also be large silk glands, and special glands which secrete distasteful or toxic substances. The developing wings are present in later stage instars and the gonads start development in the egg stage. When the larva is fully grown, hormones such as prothoracicotropic hormone (PTTH) are produced. At this point the larva stops feeding, and begins "wandering" in

5043-418: Is the only boundary between geological periods to remain formally undefined. 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. On land,

Perophthalma - Misplaced Pages Continue

5166-707: 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 . Major impact structures include the Morokweng impact structure ,

5289-622: 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. The oldest part of the Jurassic Period has historically been referred to as the Lias or Liassic, roughly equivalent in extent to

5412-461: The Cretaceous . Butterflies have a four-stage life cycle , and like other holometabolous insects they undergo complete metamorphosis . Winged adults lay eggs on the food plant on which their larvae , known as caterpillars , will feed. The caterpillars grow, sometimes very rapidly, and when fully developed, pupate in a chrysalis . When metamorphosis is complete, the pupal skin splits,

5535-585: 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 . During a tour of the region in 1795, German naturalist Alexander von Humboldt recognized carbonate deposits within the Jura Mountains as geologically distinct from

5658-513: 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: Jurassic stratigraphy is primarily based on the use of ammonites as index fossils . The first appearance datum of specific ammonite taxa

5781-479: The Lycaenidae , form mutual associations with ants. They communicate with the ants using vibrations that are transmitted through the substrate as well as using chemical signals. The ants provide some degree of protection to these larvae and they in turn gather honeydew secretions . Large blue ( Phengaris arion ) caterpillars trick Myrmica ants into taking them back to the ant colony where they feed on

5904-728: 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 . 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

6027-663: The Toarcian Age started around 183 million years ago and is marked by the Toarcian Oceanic Anoxic Event , a global episode of oceanic anoxia , ocean acidification , and elevated global temperatures associated with extinctions, likely caused by the eruption of the Karoo-Ferrar large igneous provinces . The end of the Jurassic, however, has no clear, definitive boundary with the Cretaceous and

6150-800: The Triassic aged Muschelkalk of southern Germany , but he erroneously concluded that they were older. He then named them Jura-Kalkstein ('Jura limestone') in 1799. 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

6273-474: The Weis-Fogh ' clap-and-fling ' mechanism. Butterflies are able to change from one mode to another rapidly. Butterflies are threatened in their early stages by parasitoids and in all stages by predators, diseases and environmental factors. Braconid and other parasitic wasps lay their eggs in lepidopteran eggs or larvae and the wasps' parasitoid larvae devour their hosts, usually pupating inside or outside

SECTION 50

#1732773041069

6396-455: The ZW sex-determination system where females are the heterogametic sex (ZW) and males homogametic (ZZ). Butterflies are distributed worldwide except Antarctica, totalling some 18,500 species. Of these, 775 are Nearctic ; 7,700 Neotropical ; 1,575 Palearctic ; 3,650 Afrotropical ; and 4,800 are distributed across the combined Oriental and Australian / Oceania regions. The monarch butterfly

6519-540: The lepidopteran suborder Rhopalocera , characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The group comprises the superfamilies Hedyloidea (moth-butterflies in the Americas) and Papilionoidea (all others). The oldest butterfly fossils have been dated to the Paleocene , about 56 million years ago, though molecular likely originated in

6642-402: The monarch and the painted lady , migrate over long distances. Many butterflies are attacked by parasites or parasitoids , including wasps , protozoans , flies , and other invertebrates, or are preyed upon by other organisms. Some species are pests because in their larval stages they can damage domestic crops or trees; other species are agents of pollination of some plants. Larvae of

6765-600: The non-coding DNA around the cortex gene can turn a black-winged butterfly into a butterfly with a yellow wing band. When the butterfly Bicyclus anynana is subjected to repeated inbreeding in the laboratory, there is a dramatic decrease in egg hatching. This severe inbreeding depression is considered to be likely due to a relatively high mutation rate to recessive alleles with substantial damaging effects and infrequent episodes of inbreeding in nature that might otherwise purge such mutations. Although B. anynana experiences inbreeding depression when forcibly inbred in

6888-636: The Aalenian, precessionally forced climatic changes dictated peatland wildfire magnitude and frequency. The European climate appears to have become noticeably more humid at the Aalenian-Bajocian boundary but then became more arid during the middle Bajocian. A transient ice age possibly occurred in the late Bajocian. The Callovian-Oxfordian boundary at the end of the MJCI witnessed particularly notable global cooling, potentially even an ice age. This

7011-540: The Apollos ( Parnassius ) plugs her genital opening to prevent her from mating again. The vast majority of butterflies have a four-stage life cycle: egg , larva (caterpillar), pupa (chrysalis) and imago (adult). In the genera Colias , Erebia , Euchloe , and Parnassius , a small number of species are known that reproduce semi-parthenogenetically ; when the female dies, a partially developed larva emerges from her abdomen. Butterfly eggs are protected by

7134-748: 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 . 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

7257-593: 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 . Alcide d'Orbigny in 1842 named

7380-560: The Black Jurassic in England by William Conybeare and William Phillips in 1822. William Phillips, the geologist, worked with William Conybeare to find out more about the Black Jurassic in England. 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

7503-655: 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. 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

SECTION 60

#1732773041069

7626-464: 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

7749-460: 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 . The upper boundary of the Jurassic is currently undefined, and

7872-483: 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. The Sinemurian Stage

7995-797: 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. During the Callovian, the Turgai Epicontinental Sea formed, creating a marine barrier between Europe and Asia. Madagascar and Antarctica began to rift away from Africa during

8118-742: 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

8241-572: 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

8364-526: 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. The earliest record of

8487-416: The Middle Jurassic. 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. The oldest definitive record of the cypress family ( Cupressaceae )

8610-501: The Middle to Late Jurassic, corresponding to the increasing aridity of the region. 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

8733-653: The North Atlantic Ocean with eastern Panthalassa. Palaeontological data suggest that the seaway had been open since the Early Jurassic. 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

8856-719: The North China-Amuria block had collided, resulting in the closure of the Mongol-Okhotsk Ocean . 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

8979-733: 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

9102-770: The Tithonian, known as the Early Tithonian Cooling Event (ETCE). The end of the Jurassic was marked by the Tithonian–early Barremian Cool Interval (TBCI), beginning 150 million years ago and continuing into the Early Cretaceous . 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

9225-744: The Toarcian around 174 million years ago. During the Toarcian Warm Interval, ocean surface temperatures likely exceeded 30 °C (86 °F), 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 (104 °F).The Toarcian Warm Interval is followed by the Middle Jurassic Cool Interval (MJCI) between 174 and 164 million years ago, which may have been punctuated by brief, ephemeral icehouse intervals. During

9348-430: The abdomen, generally with short prolegs on segments 3–6 and 10; the three pairs of true legs on the thorax have five segments each. Many are well camouflaged; others are aposematic with bright colours and bristly projections containing toxic chemicals obtained from their food plants. The pupa or chrysalis, unlike that of moths, is not wrapped in a cocoon. Many butterflies are sexually dimorphic . Most butterflies have

9471-405: The abdominal segments. These prolegs have rings of tiny hooks called crochets that are engaged hydrostatically and help the caterpillar grip the substrate. The epidermis bears tufts of setae , the position and number of which help in identifying the species. There is also decoration in the form of hairs, wart-like protuberances, horn-like protuberances and spines. Internally, most of the body cavity

9594-502: The adult colour pattern are marked by changes in the expression of particular transcription factors in the early pupa. The reproductive stage of the insect is the winged adult or imago . The surface of both butterflies and moths is covered by scales, each of which is an outgrowth from a single epidermal cell. The head is small and dominated by the two large compound eyes . These are capable of distinguishing flower shapes or motion but cannot view distant objects clearly. Colour perception

9717-433: The adult insect climbs out, expands its wings to dry, and flies off. Some butterflies, especially in the tropics, have several generations in a year, while others have a single generation, and a few in cold locations may take several years to pass through their entire life cycle. Butterflies are often polymorphic , and many species make use of camouflage , mimicry , and aposematism to evade their predators. Some, like

9840-467: The air for wind and scents. The antennae come in various shapes and colours; the hesperiids have a pointed angle or hook to the antennae, while most other families show knobbed antennae. The antennae are richly covered with sensory organs known as sensillae . A butterfly's sense of taste is coordinated by chemoreceptors on the tarsi , or feet, which work only on contact, and are used to determine whether an egg-laying insect's offspring will be able to feed on

9963-434: The ant eggs and larvae in a parasitic relationship. Caterpillars mature through a series of developmental stages known as instars . Near the end of each stage, the larva undergoes a process called apolysis , mediated by the release of a series of neurohormones . During this phase, the cuticle , a tough outer layer made of a mixture of chitin and specialized proteins , is released from the softer epidermis beneath, and

10086-428: 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

10209-462: 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 ) . 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

10332-658: The blues, greens, reds and iridescent colours are created by structural coloration produced by the micro-structures of the scales and hairs. As in all insects, the body is divided into three sections: the head, thorax , and abdomen . The thorax is composed of three segments, each with a pair of legs. In most families of butterfly the antennae are clubbed, unlike those of moths which may be threadlike or feathery. The long proboscis can be coiled when not in use for sipping nectar from flowers. Nearly all butterflies are diurnal , have relatively bright colours, and hold their wings vertically above their bodies when at rest, unlike

10455-441: The desiccated husk. Most wasps are very specific about their host species and some have been used as biological controls of pest butterflies like the large white butterfly . When the small cabbage white was accidentally introduced to New Zealand, it had no natural enemies. In order to control it, some pupae that had been parasitised by a chalcid wasp were imported, and natural control was thus regained. Some flies lay their eggs on

10578-688: The end of the Jurassic. The oldest unambiguous members of Podocarpaceae are known from the Jurassic, found across both hemispheres, including Scarburgia and Harrisiocarpus from the Middle Jurassic of England, as well as unnamed species from the Middle-Late Jurassic of Patagonia. 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

10701-653: 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 corystosperm 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 Early Jurassic. Conifers formed

10824-419: The epidermis begins to form a new cuticle. At the end of each instar, the larva moults , the old cuticle splits and the new cuticle expands, rapidly hardening and developing pigment. Development of butterfly wing patterns begins by the last larval instar. Caterpillars have short antennae and several simple eyes . The mouthparts are adapted for chewing with powerful mandibles and a pair of maxillae, each with

10947-417: 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

11070-506: The evidence for this is primarily European, probably controlled by changes in eustatic sea level. 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

11193-741: The family Hesperiidae (skippers). Molecular clock estimates suggest that butterflies originated sometime in the Late Cretaceous , but only significantly diversified during the Cenozoic, with one study suggesting a North American origin for the group. The oldest American butterfly is the Late Eocene Prodryas persephone from the Florissant Fossil Beds , approximately 34   million years old. Butterflies are divided into seven families that contain

11316-405: The fauna transitioned from the Triassic fauna, dominated jointly by dinosauromorph and pseudosuchian archosaurs , to one dominated by dinosaurs alone. The first stem-group birds appeared during the Jurassic, evolving from a branch of theropod dinosaurs. Other major events include the appearance of the earliest crabs and modern frogs , salamanders and lizards . Mammaliaformes , one of

11439-472: The few cynodont lineages to survive the end of the Triassic, continued to diversify throughout the period, with the Jurassic seeing the emergence of the first crown group 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 . Modern sharks and rays first appeared and diversified during

11562-686: The first appearance of Cardioceras redcliffense as the lower boundary. 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

11685-465: 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 . 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,

11808-409: The friction of their overlapping parts. The front two segments have a pair of spiracles which are used in respiration. The abdomen consists of ten segments and contains the gut and genital organs. The front eight segments have spiracles and the terminal segment is modified for reproduction. The male has a pair of clasping organs attached to a ring structure, and during copulation, a tubular structure

11931-402: The genus Elatides . The Jurassic also saw the first appearances of some modern genera of cypresses, such as Sequoia . 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

12054-500: The grass was growing. The earliest Lepidoptera fossils date to the Triassic - Jurassic boundary, around 200   million years ago. Butterflies evolved from moths, so while the butterflies are monophyletic (forming a single clade ), the moths are not. The oldest known butterfly is Protocoeliades kristenseni from the Palaeocene aged Fur Formation of Denmark, approximately 55   million years old, which belongs to

12177-1030: The laboratory it recovers within a few generation when allowed to breed freely. During mate selection, adult females do not innately avoid or learn to avoid siblings, implying that such detection may not be critical to reproductive fitness. Inbreeding may persist in B anynana because the probability of encountering close relatives is rare in nature; that is, movement ecology may mask the deleterious effect of inbreeding resulting in relaxation of selection for active inbreeding avoidance behaviors. Butterflies feed primarily on nectar from flowers. Some also derive nourishment from pollen , tree sap, rotting fruit, dung, decaying flesh, and dissolved minerals in wet sand or dirt. Butterflies are important as pollinators for some species of plants. In general, they do not carry as much pollen load as bees , but they are capable of moving pollen over greater distances. Flower constancy has been observed for at least one species of butterfly. Adult butterflies consume only liquids, ingested through

12300-545: 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

12423-416: 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

12546-403: 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

12669-506: The majority of moths which fly by night, are often cryptically coloured (well camouflaged), and either hold their wings flat (touching the surface on which the moth is standing) or fold them closely over their bodies. Some day-flying moths, such as the hummingbird hawk-moth , are exceptions to these rules. Butterfly larvae , caterpillars , have a hard ( sclerotised ) head with strong mandibles used for cutting their food, most often leaves. They have cylindrical bodies, with ten segments to

12792-428: 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 from

12915-401: The name is ancient, but modern Dutch and German use different words ( vlinder and Schmetterling ) and the common name often varies substantially between otherwise closely related languages. A possible source of the name is the bright yellow male of the brimstone ( Gonepteryx rhamni ); another is that butterflies were on the wing in meadows during the spring and summer butter season while

13038-422: The ocean floor acting as a buffer against large CO 2 emissions. The climate of the Jurassic was generally warmer than that of present, by around 5–10 °C (9–18 °F), with atmospheric carbon dioxide likely about four times higher. Intermittent "cold snap" intervals are known to have occurred during this time period, however, interrupting the otherwise warm greenhouse climate. Forests likely grew near

13161-460: 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. The Jurassic also witnessed the decline of the Pangaean megamonsoon that had characterised the preceding Permian and Triassic periods. Variation in the frequency of wildfire activity in the Jurassic

13284-513: The outside of caterpillars and the newly hatched fly larvae bore their way through the skin and feed in a similar way to the parasitoid wasp larvae. Predators of butterflies include ants, spiders, wasps, and birds. Jurassic The start of the Jurassic was marked by the major Triassic–Jurassic extinction event , associated with the eruption of the Central Atlantic Magmatic Province (CAMP). The beginning of

13407-497: The period, while the first known crown-group teleost fish appeared near the end of the period. The flora was dominated by ferns and gymnosperms , including conifers , of which many modern groups made their first appearance during the period, as well as other groups like the extinct Bennettitales . The chronostratigraphic term "Jurassic" is linked to the Jura Mountains , a forested mountain range that mainly follows

13530-592: 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". 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

13653-611: 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 (14 °F) warmer than present, and coral reefs grew 10° of latitude further north and south. The Intertropical Convergence Zone likely existed over

13776-529: The proboscis. They sip water from damp patches for hydration and feed on nectar from flowers, from which they obtain sugars for energy, and sodium and other minerals vital for reproduction. Several species of butterflies need more sodium than that provided by nectar and are attracted by sodium in salt; they sometimes land on people, attracted by the salt in human sweat. Some butterflies also visit dung and scavenge rotting fruit or carcasses to obtain minerals and nutrients. In many species, this mud-puddling behaviour

13899-431: The quest for a suitable pupation site, often the underside of a leaf or other concealed location. There it spins a button of silk which it uses to fasten its body to the surface and moults for a final time. While some caterpillars spin a cocoon to protect the pupa, most species do not. The naked pupa, often known as a chrysalis, usually hangs head down from the cremaster, a spiny pad at the posterior end, but in some species

14022-648: 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 . The Callovian is derived from the Latinized name of the village of Kellaways in Wiltshire , England, and

14145-573: The three series of von Buch in the Swabian Jura into six subdivisions defined by ammonites and other fossils. 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. The Jurassic Period

14268-407: 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 . During

14391-585: 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

14514-474: 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

14637-569: Was governed by the 405 kyr eccentricity cycle. Thanks to the breakup of Pangaea, the hydrological cycle during the Jurassic was significantly enhanced. 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

14760-582: 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 . The Oxfordian

14883-490: Was present in the Northern Hemisphere during both the early Pliensbachian and the latest Pliensbachian. There was a spike in global temperatures of around 4–8 °C (7–14 °F) 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

15006-687: Was ratified in 2000. The beginning of the Sinemurian is defined by the first appearance of the ammonite Vermiceras quantoxense . 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

15129-430: Was ratified in 2021. The boundary is defined by the first appearance of ammonites marking the boreal Bauhini Zone and the subboreal Baylei Zone. 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 ,

#68931