Triassic period 251 - 199. 6 million years ago ↓ PЄ Є O S D C P T J K PG N
Mean atmospheric O2 content over period duration	ca. The Precambrian ( Pre-Cambrian) is an informal name for the supereon comprising the eons of the Geologic timescale that came before the current The Cambrian is a geologic period and system that began about Ma (million years ago at the end of the Proterozoic eon and ended about Ma with The Ordovician is a geologic period and system, the second of six of the Paleozoic era, and covers the time between 488 The Silurian is a geologic period and system that extends from the end of the Ordovician period about 443 The Devonian is a geologic period and system of the Paleozoic era spanning from to  million years ago. The Carboniferous is a geologic period and system that extends from the end of the Devonian period about 359 The Permian is a geologic period and system that extends from 299 The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of The Paleogene (alternatively Palaeogene) is a geologic period and system that began 65 The Neogene is a geologic period and system starting 2303 ± 0 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the 16 Vol %[1] (80 % of modern level)
Mean atmospheric CO2 content over period duration	ca. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single 1750 ppm[2] (6 times pre-industrial level)
Mean surface temperature over period duration	ca. "Parts-per" notation is used especially in Science and Engineering, to denote Ratios (relative proportions in measured quantities particularly 17°C [3] (3°C above modern level)
Key events in the Triassic view • discuss • edit -255 — – -250 — – -245 — – -240 — – -235 — – -230 — – -225 — – -220 — – -215 — – -210 — – -205 — – -200 — – Jurassic Permian Triassic Induan Olenekian Anisian Ladinian Carnian Norian Rhaetian           ← Mass extinction ← Full recovery of woody trees[4] ← Coals return[5] ← Scleractinian corals & calcified sponges[6] T r i a s s i c  Mesozoic  Palæozoic An approximate timescale of key Triassic events. The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning The Permian is a geologic period and system that extends from 299 The Induan (also known as the Feixianguanian) is the first stage of the Early Triassic epoch. The Olenekian (also known as the Yongningzhenian) is a stage of the Early Triassic epoch. In the Geologic timescale, the Anisian is the age of the Middle Triassic epoch and lasted from 245 million years ago until 237 million years The Ladinian (also known as the Falangian) is a stage of the Middle Triassic epoch. The Carnian (less commonly Karnian) is the lowermost stage of the Upper Triassic series (or earliest age of the Late Triassic The Norian Stage was a portion of the Triassic Geological period. See Raetians for the Alpine people of antiquity See Romansh language for the Rhaetian language The Permian–Triassic (P–Tr extinction event, informally known as the Great Dying, was an Extinction event that occurred, and 70 percent of terrestrial Scleractinia, also called Stony Corals, are exclusively marine animals they are very similar to Sea anemones but generate a hard skeleton The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. The Paleozoic or Palaeozoic Era (from the Greek palaio (παλαιο "old" and zoe (ζωη "life" meaning "ancient life" Axis scale: millions of years ago.

The Triassic is a geologic period and system that extends from about 251 to 199 Ma (million years ago). Annum is one form of the Latin noun meaning Year, not a form normally used for derivatives in modern languages the accusative singular As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. The Permian is a geologic period and system that extends from 299 The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning Both the start and end of the Triassic are marked by major extinction events. An extinction event (also known as mass extinction; extinction-level event, ELE is a sharp decrease in the number of Species in a relatively short period The extinction event that closed the Triassic period has recently been more accurately dated, but as with most older geologic periods, the rock beds that define the start and end are well identified, but the exact dates of the start and end of the period are uncertain by a few million years.

During the Triassic, both marine and continental life show an adaptive radiation beginning from the starkly impoverished biosphere that followed the Permian-Triassic extinction. An adaptive radiation is a rapid Evolutionary radiation characterized by an increase in the morphological and ecological diversity of a single rapidly diversifying lineage The biosphere is the broadest level of ecological study the global sum of all Ecosystems. The Permian–Triassic (P–Tr extinction event, informally known as the Great Dying, was an Extinction event that occurred, and 70 percent of terrestrial Corals of the hexacorallia group made their first appearance. Zoantharia (also known as Hexacorallia, as they have 6-fold symmetry is a subclass of the class Anthozoa within the phylum Cnidaria. The first flowering plants (Angiosperms) may have evolved during the Triassic, as did the first flying vertebrates, the pterosaurs. The flowering plants or angiosperms ( Angiospermae or Magnoliophyta) are the most widespread group For other meanings see Pterodactyl (disambiguation. Pterosaurs (ˈtɛrəsɔr from the Greek πτερόσαυρος pterosauros

Dating and subdivisions

The Triassic was named in 1834 by Friedrich Von Alberti from the three distinct layers (Latin trias meaning triad) —red beds, capped by chalk, followed by black shales— that are found throughout Germany and northwest Europe, called the 'Trias'. Dr Friedrich August von Alberti ( September 4, 1795 &mdash September 12, 1878) was a German Geologist whose ground-breaking The term red beds usually refers to strata of reddish -colored sedimentary rocks such as Sandstone, Siltstone or Shale that Chalk (ʧɔːk is a soft white porous Sedimentary rock, a form of Limestone composed of the Mineral Calcite. Shale (also called mudstone) is a fine-grained Sedimentary rock whose original constituents were Clay minerals or Muds It is characterized by Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe.

The Triassic is usually separated into Early, Middle, and Late Triassic Epochs, and the corresponding rocks are referred to as Lower, Middle, or Upper Triassic. The Early Triassic (also known as Lower Triassic, Buntsandstein, or Scythian) is the first of three epochs of the Triassic The Middle Triassic (also known as Muschelkalk) is the second of three epochs of the Triassic period. The Late Triassic (also known as Upper Triassic, or Keuper) is the third and final of three epochs of the Triassic period. The geologic time scale is a chronologic schema (or idealized Model) relating Stratigraphy to time that is used by Geologists and other The faunal stages from the youngest to oldest are:

Paleogeography

230 Ma plate tectonic reconstruction

During the Triassic, almost all the Earth's land mass was concentrated into a single supercontinent centered more or less on the equator, called Pangaea ("all the land"). In Geology, a supercontinent is a Landmass comprising more than one Continental core or Craton. Pangaea, Pangæa or Pangea (pænˈdʒiːə from παν pan, meaning entire, and Γαῖα Gaea, meaning Earth in From the east a vast gulf entered Pangaea, the Tethys sea. The Tethys Ocean was a Mesozoic era Ocean that existed between the continents of Gondwana and Laurasia before the opening of the Indian It opened farther westward in the mid-Triassic, at the expense of the shrinking Paleo-Tethys Ocean, an ocean that existed during the Paleozoic. The Paleo-Tethys Ocean was an ancient Paleozoic Ocean. It was located between the Paleocontinent Gondwana and the so called Hunic terranes The Paleozoic or Palaeozoic Era (from the Greek palaio (παλαιο "old" and zoe (ζωη "life" meaning "ancient life" The remaining shores were surrounded by the world-ocean known as Panthalassa ("all the sea"). Panthalassa ( Greek, meaning 'all seas' also known as the Panthalassic Ocean, was the vast global Ocean that surrounded the Supercontinent All the deep-ocean sediments laid down during the Triassic have disappeared through subduction of oceanic plates; thus, very little is known of the Triassic open ocean. In Geology, a subduction zone is an area on Earth where two tectonic plates meet and move towards one another with one sliding underneath the other The supercontinent Pangaea was rifting during the Triassic—especially late in the period—but had not yet separated. The first nonmarine sediments in the rift that marks the initial break-up of Pangea—which separated New Jersey from Morocco—are of Late Triassic age; in the U. In Geology, a rift is a place where the Earth 's crust and Lithosphere are being pulled apart and is an example of Extensional tectonics New Jersey ( is a state in the Mid-Atlantic and Northeastern regions of the United States. Morocco (المغرب "al-Maghrib" officially the Kingdom of Morocco (المملكة المغربية is a country located in North Africa S. , these thick sediments comprise the Newark Group. The Newark Group, also known as the Newark Supergroup, is an assemblage of Triassic Sedimentary rocks which outcrop intermittently along the United ^[7] Because of the limited shoreline of one super-continental mass, Triassic marine deposits are globally relatively rare, despite their prominence in Western Europe, where the Triassic was first studied. Western Europe at its most general meaning means 'all the countries in the West of Europe ' In North America, for example, marine deposits are limited to a few exposures in the west. Thus Triassic stratigraphy is mostly based on organisms living in lagoons and hypersaline environments, such as Estheria crustaceans. Stratigraphy, a branch of Geology, studies rock layers and layering ( stratification)

Climate

Middle Triassic marginal marine sequence, southwestern Utah

The Triassic climate was generally hot and dry, forming typical red bed sandstones and evaporites. The State of Utah (ˈjuːtɔː or) is a western state of the United States. The term red beds usually refers to strata of reddish -colored sedimentary rocks such as Sandstone, Siltstone or Shale that Sandstone is a Sedimentary rock composed mainly of Sand -size Mineral or rock grains. Evaporites (iˈvæpəraɪt are water-soluble Mineral sediments that result from the Evaporation of bodies of surficial Water. There is no evidence of glaciation at or near either pole; in fact, the polar regions were apparently moist and temperate, a climate suitable for reptile-like creatures. "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. Pangaea's large size limited the moderating effect of the global ocean; its continental climate was highly seasonal, with very hot summers and cold winters. Continental climate is a Climate that is characterized by Winter Temperatures cold enough to support a fixed period of Snow cover each Year ^[8] It probably had strong, cross-equatorial monsoons. A cross is a geometrical figure consisting of two lines or bars perpendicular to each other dividing one or two of the lines in half The equator (sometimes referred to colloquially as "the Line") is the intersection of the Earth 's surface with the plane perpendicular to the A monsoon is a seasonal prevailing wind which lasts for several months ^[9]

Life

Triassic flora as depicted in Meyers Konversations-Lexikon (1885-90)

Three categories of organisms can be distinguished in the Triassic record: holdovers from the Permian-Triassic extinction, new groups which flourished briefly, and other new groups which went on to dominate the Mesozoic world. Meyers Konversations-Lexikon was a major German Encyclopedia that existed in various editions from 1839 until 1984 when it merged with the Brockhaus The Permian–Triassic (P–Tr extinction event, informally known as the Great Dying, was an Extinction event that occurred, and 70 percent of terrestrial The Mesozoic Era is one of three geologic eras of the Phanerozoic eon.

In marine environments, new modern types of corals appeared in the Early Triassic, forming small patches of reefs of modest extent compared to the great reef systems of Devonian times or modern reefs. An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere. Corals are Marine organisms from the class Anthozoa and exist as small Sea anemone –like Polyps typically in colonies of many In nautical terminology a reef is a rock, sandbar, or other feature lying beneath the surface of the water (six fathoms or less at low water The Devonian is a geologic period and system of the Paleozoic era spanning from to  million years ago. The shelled cephalopods called ammonites recovered, diversifying from a single line that survived the Permian extinction. The cephalopods ( Greek plural (kephalópoda "head-feet" are the Mollusc class Cephalopoda characterized by Ammonites are an extinct group of marine animals of the subclass Ammonoidea in the class Cephalopoda phylum The fish fauna was remarkably uniform, reflecting the fact that very few families survived the Permian extinction. There were also many types of marine reptiles. These included the Sauropterygia, which featured pachypleurosaurs and nothosaurs (both common during the Middle Triassic, especially in the Tethys region), placodonts, and the first plesiosaurs; the first of the lizardlike Thalattosauria (askeptosaurs); and the highly successful ichthyosaurs, which appeared in Early Triassic seas and soon diversified, some eventually developing to huge size during the late Triassic. Sauropterygia (" Lizard Flippers quot is a group of very successful aquatic Reptiles that flourished during the Age of the Dinosaurs before Pachypleurosaurs were primitive Sauropterygian reptiles that vaguely resembled aquatic lizards and were limited to the Triassic period Nothosaurs (order Nothosauroidea) were Triassic marine Sauropterygian Reptiles that may have lived like seals of today catching The Tethys Ocean was a Mesozoic era Ocean that existed between the continents of Gondwana and Laurasia before the opening of the Indian Placodonts (" Tablet Teeth " were a group of marine Reptiles that lived during the Triassic period becoming extinct at the end Plesiosaurs (ˈpliːziəˌsɔɹ ( Greek: plesios/πλησιος meaning 'near' or 'close to' and sauros/σαυρος meaning Thalattosaurs (meaning "ocean lizards" are a group of prehistoric Marine reptiles which lived during the mid-late Triassic Period Askeptosaurus is an extinct genus of aquatic Reptile related to the thalattosaurian group Ichthyosaurs ( Greek for 'fish lizard' - ιχθυς / ichthyos meaning 'fish' and σαυρος / sauros meaning 'lizard' were giant

On land, the holdover plants included the lycophytes, the dominant cycads, ginkgophyta (represented in modern times by Ginkgo biloba) and glossopterids. The Division Lycopodiophyta (sometimes called Lycophyta) is a tracheophyte subdivision of the Kingdom Plantae It is the oldest extant (living Cycads are a group of Seed plants characterized by a large crown of compound leaves and a stout trunk. The Ginkgoaceae is a family of Gymnosperms which appeared during the Mesozoic Era of which the only extant representative is Ginkgo biloba Ginkgo is a genus of highly unusual non-flowering plants with one extant species G Glossopteridales is an extinct order of plants belonging to Pteridospermatophyta, or Seed Ferns The spermatophytes, or seed plants came to dominate the terrestrial flora: in the northern hemisphere, conifers flourished. The spermatophytes (from the Greek word "Σπερματόφυτα" (also known as phanerogams) comprise those Plants that produce Seeds They are Glossopteris (a seed fern) was the dominant southern hemisphere tree during the Early Triassic period. Glossopteris ( Greek glossa (γλώσσα meaning "tongue" because the leaves were tongue-shaped is the largest and best-known Genus Pteridospermatophyta, also called seed ferns, is an extinct Spermatophyte group of the Plantae kingdom.

Temnospondyl amphibians were among those groups that survived the Permian-Triassic extinction, some lineages (e. Temnospondyli (from Greek τεμνειν temnein = "to cut" + σπονδυλως spondulos = "vertebra" are an important and extremely diverse Prehistoric amphibian Amphibians (class Amphibia such as Frogs Toads Salamanders Newts Gymnophiona, Sirens and g. Trematosaurs) flourishing briefly in the Early Triassic, while others (e. g. capitosaurs) remained successful throughout the whole period, or only came to prominence in the Late Triassic (e. g. plagiosaurs, metoposaurs). As for other amphibians, the first Lissamphibia are known from the Early Triassic, but the group as a whole did not become common until the Jurassic, when the temnospondyls had become very rare. The subclass Lissamphibia includes all recent Amphibians Extant amphibians fall into one of three orders - the Anura ( Frogs including The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning

Middle and Upper Triassic shallow marine sequence, Makhtesh Ramon, Israel. Makhtesh Ramon (מכתש רמון litRamon Crater is a spectacular geological feature of Israel's Negev Desert.

Archosauromorph reptiles — especially archosaurs — progressively replaced the synapsids that had dominated the Permian. Archosauromorpha ( Greek for "ruling lizard forms" is an Infraclass of Diapsid Reptiles that first appeared during the late Permian Archosaurs ( Greek for 'ruling lizards' are a group of Diapsid Reptiles represented by Modern birds and Crocodilians This group also Synapsids ('fused arch' also known as theropsids ('beast face' are a class of Animals that includes Mammals and everything closer to mammals than Although Cynognathus was a characteristic top predator in earlier Triassic (Olenekian and Anisian) Gondwana, and both kannemeyeriid dicynodonts and gomphodont cynodonts remained important herbivores during much of the period. Cynognathus was a metre-long Predator of the Lower Triassic. It was one of the more Mammal -like of the " Mammal-like reptiles " The Olenekian (also known as the Yongningzhenian) is a stage of the Early Triassic epoch. In the Geologic timescale, the Anisian is the age of the Middle Triassic epoch and lasted from 245 million years ago until 237 million years Gondwana (ɡɒnˈdwɑːnə originally Gondwanaland) was a southern Supercontinent that existed about 500 to 200 Ma ago Kannemeyeriidae is a family of large stocky beaked and sometimes tusked Dicynodonts they were the dominant large terrestrial herbivores through most of the The Dicynodontia are a Taxon of Therapsids or Mammal-like reptiles. Cynodonts, or 'dog teeth' are a taxon of Therapsids which includes modern mammals and their extinct close relatives Herbivory is a form of Predation in which an Organism, known as a herbivore, consumes principally Autotrophs ref name=Campbell>Campbell By the end of the Triassic, synapsids played only bit parts. During the Carnian (early part of the Late Triassic), some advanced cynodont gave rise to the first mammals. The Carnian (less commonly Karnian) is the lowermost stage of the Upper Triassic series (or earliest age of the Late Triassic At the same time the Ornithodira, which until then had been small and insignificant, evolved into pterosaurs and a variety of dinosaurs. Ornithodira is a Clade within the larger group Archosauria In 1986 Jacques Gauthier coined the name for a node clade containing the last common For other meanings see Pterodactyl (disambiguation. Pterosaurs (ˈtɛrəsɔr from the Greek πτερόσαυρος pterosauros The Crurotarsi were the other important archosaur clade, and during the Late Triassic these also reached the height of their diversity, with various groups including the phytosaurs, aetosaurs, several distinct lineages of Rauisuchia, and the first crocodylians (the Sphenosuchia). The Crurotarsi ("cross-ankles" are a group of archosaurs, whose name was erected as a node-based clade by Paul Sereno in 1991 A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor Phytosaurs - family Phytosauridae or Parasuchidae - were a group of large (2 to 12 meters long - average size 3 to 4 meters semi-aquatic predatory The Aetosaurs (literally "Eagle Lizards" ( family) Stagonolepididae, Order Aetosauria) are an Extinct Clade of heavily Rauisuchia are a poorly known assemblage of predatory and mostly large (often 4 to 6 meters Triassic Archosaurs Originally it was believed that they were related Crocodilia is an order of large Reptiles that appeared about 84 million years ago in the late Cretaceous Period ( Campanian stage Sphenosuchia is the name of a suborder of basal Crocodylomorphs that first appeared in the Triassic and occurred into the Middle Jurassic Meanwhile the stocky herbivorous rhynchosaurs and the small to medium-sized insectivorous or piscivorous Prolacertiformes were important basal archosauromorph groups throughout most of the Triassic. Rhynchosaurs were a group of unusual Triassic Diapsid Reptiles related to the archosaurs. Prolacertiformes (sometimes called protorosaurs) were an order of archosauromorph Reptiles that lived during the Permian and Triassic In Phylogenetics, a basal Clade is the earliest clade to branch in a larger clade it appears at the base of a cladogram

Among other reptiles, the earliest turtles, like Proganochelys and Proterochersis, appeared during the Norian (middle of the Late Triassic). Proganochelys is the oldest Turtle species discovered to date known only from fossils found in Germany and Thailand in strata from the The Norian Stage was a portion of the Triassic Geological period. The Lepidosauromorpha—specifically the Sphenodontia—are first known in the fossil record a little earlier (during the Carnian). Lepidosauromorpha is a group of Reptiles comprising all Diapsids closer to Lizards than to Archosaurs (including Crocodiles and Sphenodontia is an order of lizard-like reptiles that includes only one living genus the Tuatara ( Sphenodon) The Procolophonidae were an important group of small lizard-like herbivores. The Procolophonids - family Procolophonidae (Superfamily Procolophonoidea)- are a group of small reptiles

Archosaurs were initially rarer than the therapsids which had dominated Permian terrestrial ecosystems, but they began to displace therapsids in the mid-Triassic. Therapsids are an order of Synapsids (Class Synapsida Traditionally synapsids were referred to as Reptiles and were known as The Permian is a geologic period and system that extends from 299 ^[10] This "Triassic Takeover" may have contributed to the evolution of mammals by forcing the surviving therapsids and their mammaliform successors to live as small, mainly nocturnal insectivores; nocturnal life probably forced at least the mammaliforms to develop fur and higher metabolic rates. __FORCETOC__ See also Evolutionary history of life The evolution of mammals from Synapsids (mammal-like " Reptiles quot was a gradual process Mammaliaformes ("mammal-shaped" is a Clade that contains the Mammals and their closest extinct relatives An insectivore is a type of carnivore with a diet that consists chiefly of Insects and similar small creatures Basal metabolic rate ( BMR) is the amount of energy expended while at rest in a neutrally temperate environment in the post-absorptive state (meaning that the digestive system ^[11]

Coal

When the Triassic commenced a coal hiatus (no coal) appeared simultaneously all over the world at the Permian-Triassic boundary ^[5] Probably a sudden large drop in sea level permitted whatever caused the hiatus, and thus accounts for the sudden appearance, for at the close of the Permian there was an even quicker drop in sea level than the slower drop that had occurred in its last half, the sharpest in history ^[12]. The Permian is a geologic period and system that extends from 299 There had been many salt deposits in Permian basins in the last half ^[13]. There are large salt basins in the southwest United States and a very large basin is suspected in central Canada, now eroded away ^[14]. Possibly a tsunami opened up some of these basins, evaporation from which would have previously delayed the sea level decline, and thus account for that quicker drop at the end. This or something like this could account for a subsequent rapid rise when the inland sea created evaporated again after barriers were reestablished. Glaciers can be safely ruled out because there is no evidence of glaciers anywhere during the Triassic. Immediately above the boundary the glossopteris flora was suddenly ^[15] largely displaced by an Australia wide coniferous flora containing few species and containing a lycopod herbaceous under story. Conifers became common in Eurasia also. Each of these groups of conifers arose from endemic species because conifers are very poor at crossing ocean barriers and they remained separated for hundreds of millions of years, largely to the present. Podocarpis was south and Pines, Junipers, and Sequoias were north, for instance. The dividing line ran through the Amazon Valley, across the Sahara, and north of Arabia, India, Thailand, and Australia ^{[16] [17]}. It has been suggested that there was a climate barrier for the conifers ^[18], although water barriers are more plausible. If so, something that can cross at least short water barriers must have been involved in producing the coal hiatus. Hot climate could have been an important auxiliary factor across Antarctica or the Bering Straights , however. There was a spike of fern and lycopod spores immediately after the close of the Permian ^[19]. In addition there was also a spike of fungal spores immediately after the Permian-Triassic boundary ^[20]. This spike may have lasted 50,000 years in Italy and 200,000 years in China and must have contributed to the climate warmth. If so, something besides an instant catastrophe must have been involved to cause the coal hiatus because fungi would surely have removed all dead vegetation and coal forming detritus in a few decades in most tropical places. Besides, the fungal spores rose gradually and declined similarly. There was also much woody debris. Each phenomenon would hint at widespread vegetative death. Whatever caused the coal hiatus must have started in North America 25 million years sooner ^[21]. Weesner believes that Mastotermitidae termites may go back to the Permian ^[22] and fossil wings have been discovered in the Permian of Kansas which have a close resemblance to wings of Mastotermes of the Mastotermitidae, which is the most primitive living termite and which is thought to be the descendant of Cryptocercus genus, the wood roach. Mastotermes darwiniensis, Common names Giant Northern Termite and Darwin Termite, is a Termite Species found only This fossil is called Pycnoblattina. It folded its wings in a convex pattern between segments 1a and 2a. Mastotermes is the only living insect that does the same ^[23], so it is possible that they are responsible for the coal hiatus. This is plausible because termites attack the trunk, which is the most vulnerable part. Modern termites also eat detritus. If parasitoids were what brought back the coal after about 10 million years past the opening, their initial evolution must have taken place in or near Australia because the coal reappeared there first by several million years ^[24]. A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host Organism which it ultimately kills Ancestors of the Evaniidae, which parasitize roach egg sacs ^[25], could have been the ones involved, and this may explain why termites evolved separated eggs except in Mastotermitidae. The ensign wasps (family Evaniidae) are a small cosmopolitan group of very distinctive appearance with 20 extant genera containing some 450 known species During the Triassic coal hiatus in the beginning of the Triassic it was possible to find stump impressions up to 45 cm (17. 7 in) and root impressions up to 18 cm (7 in) in south Australia, but no roots or logs. The soil was extremely low in organic matter and there was no detritus at all ^[26].

Lagerstätten

Triassic sandstone near Stadtroda, Germany. Stadtroda (Roda until 1925 is a town of 6293 people located in Thuringia, Germany.

The Monte San Giorgio lagerstätte, now in the Lake Lugano region of northern Italy and Switzerland, was in Triassic times a lagoon behind reefs with an anoxic bottom layer, so there were no scavengers and little turbulence to disturb fossilization, a situation that can be compared to the better-known Jurassic Solnhofen limestone lagerstätte. Monte San Giorgio is a wooded mountain (1096 m above sea level located in the south of canton Ticino in Switzerland. A Lagerstätte ( German; literally place of storage; plural Lagerstätten) is a sedimentary deposit that exhibits extraordinary fossil Lake Lugano ( Italian: Lago di Lugano or Ceresio) is a Lake in the south-east of Switzerland, at the border between Switzerland and Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest Switzerland (English pronunciation; Schweiz Swiss German: Schwyz or Schwiiz Suisse Svizzera Svizra officially the Swiss Confederation A lagoon is a body of comparatively shallow salt or Brackish water separated from the deeper Sea by a shallow or exposed sandbank, coral The Solnhofen limestone is a Jurassic Konservat-Lagerstätte that preserves a rare assemblage of Fossilized organisms some of which such as sea jellies The remains of fish and various marine reptiles (including the common pachypleurosaur Neusticosaurus, and the bizarre long-necked archosauromorph Tanystropheus), along with some terrestrial forms like Ticinosuchus and Macrocnemus, have been recovered from this locality. Pachypleurosaurs were primitive Sauropterygian reptiles that vaguely resembled aquatic lizards and were limited to the Triassic period Archosauromorpha ( Greek for "ruling lizard forms" is an Infraclass of Diapsid Reptiles that first appeared during the late Permian Tanystropheus, or Long Necked One was a 6  Metre (20  ft) long Reptile that dated from the Middle Triassic period Ticinosuchus is an Extinct Genus of Rauisuchian Archosaur that was about 3 m (10 ft long Macrocnemus is an Extinct Genus of prolacertiform Reptile from the Middle Triassic of Europe. All these fossils date from the Anisian/Ladinian transition (about 237 million years ago). In the Geologic timescale, the Anisian is the age of the Middle Triassic epoch and lasted from 245 million years ago until 237 million years The Ladinian (also known as the Falangian) is a stage of the Middle Triassic epoch.

Late Triassic extinction event

Main article: Triassic-Jurassic extinction event

The Triassic period ended with a mass extinction, which was particularly severe in the oceans; the conodonts disappeared, and all the marine reptiles except ichthyosaurs and plesiosaurs. Conodonts are extinct chordates resembling eels classified in the class Conodonta. Invertebrates like brachiopods, gastropods, and molluscs were severely affected. Brachiopods (from Latin brachium, arm + New Latin -poda, foot are a small phylum of Benthic Invertebrates Also The class Gastropoda or the gastropods, also previously known as gasteropods, or univalves, and more commonly known as Snails Molluscs are animals belonging to the phylum Mollusca. There are around 250000 extant Species within the phylum with an estimated 70000 In the oceans, 22% of marine families and possibly about half of marine genera went missing according to University of Chicago paleontologist Jack Sepkoski. The University of Chicago is a Private university located principally in the Hyde Park neighborhood of Chicago. J John Sepkoski Jr. ( July 26, 1948 - May 1, 1999) was a University of Chicago Paleontologist.

Though the end-Triassic extinction event was not equally devastating everywhere in terrestrial ecosystems, several important clades of Crurotarsi (large archosaurian reptiles previously grouped together as the thecodonts) disappeared, as did most of the large labyrinthodont amphibians, groups of small reptiles, and some synapsids (except for the proto-mammals). The Crurotarsi ("cross-ankles" are a group of archosaurs, whose name was erected as a node-based clade by Paul Sereno in 1991 Thecodont ("socket-toothed" reptile now considered an obsolete term was formerly used to describe a diverse range of early Archosaurs that first appeared in the Some of the early, primitive dinosaurs also went extinct, but other more adaptive dinosaurs survived to evolve in the Jurassic. Surviving plants that went on to dominate the Mesozoic world included modern conifers and cycadeoids.

It is not certain what caused this Late Triassic extinction, which was accompanied by huge volcanic eruptions about 202 to 191 million years ago [(40Ar/39Ar dates^[27])] known as the Central Atlantic Magmatic Province [(CAMP)]^[28], one of the largest inland recorded volcanic event since the planet cooled and stabilized, as the supercontinent Pangaea began to break apart. Plate tectonics and hotspots Divergent plate boundaries At the The Central Atlantic magmatic province (CAMP was formed during the breakup of Pangaea during the Mesozoic Era Other possible but less likely causes for the extinction events include global cooling or even a bolide impact, for which an impact crater surrounding Manicouagan Reservoir in Quebec, Canada, has been singled out. Manicouagan Reservoir (also Lake Manicouagan) is an annular lake in central Quebec, Canada. Quebec (kwɨˈbɛk Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page At the Manicouagan impact crater, however, recent research has shown that the impact melt within the crater has an age of 214±1 Ma. The date of the Triassic-Jurassic boundary has also been more accurately fixed recently, at 201. 58±0. 28 Ma. Both dates are gaining accuracy by using more accurate forms of radiometric dating, in particular the decay of uranium to lead in zircons formed at the impact. So the evidence suggests the Manicouagan impact preceded the end of the Triassic by approximately 10±2 Ma. Therefore it could not be the immediate cause of the observed mass extinction. ^[29]

The number of Late Triassic extinctions is disputed. Some studies suggest that there are at least two periods of extinction towards the end of the Triassic, between 12 and 17 million years apart. But arguing against this is a recent study of North American faunas. In the Petrified Forest of northeast Arizona there is a unique sequence of latest Carnian-early Norian terrestrial sediments. Petrified Forest National Park is along Interstate 40 between Holbrook and Navajo, in the United States. An analysis in 2002 found no significant change in the paleoenvironment. ^[30] Phytosaurs, the most common fossils there, experienced a change-over only at the genus level, and the number of species remained the same. Phytosaurs - family Phytosauridae or Parasuchidae - were a group of large (2 to 12 meters long - average size 3 to 4 meters semi-aquatic predatory Some Aetosaurs, the next most common tetrapods, and early dinosaurs, passed through unchanged. The Aetosaurs (literally "Eagle Lizards" ( family) Stagonolepididae, Order Aetosauria) are an Extinct Clade of heavily However, both Phytosaurs and Aetosaurs were among the groups of archosaur reptiles completely wiped out by the end-Triassic extinction event.

It seems likely then that there was some sort of end-Carnian extinction, when several herbivorous archosauromorph groups died out, while the large herbivorous therapsids— the kannemeyeriid dicynodonts and the traversodont cynodonts— were much reduced in the northern half of Pangaea (Laurasia). Therapsids are an order of Synapsids (Class Synapsida Traditionally synapsids were referred to as Reptiles and were known as Kannemeyeriidae is a family of large stocky beaked and sometimes tusked Dicynodonts they were the dominant large terrestrial herbivores through most of the Traversodonts were a group of herbivorous Cynodonts Their Postcanine teeth is modified and expanded in width for chewing Plants Traversodonts Laurasia (lɔˈreɪʃiə lɔˈreɪʒə was a Supercontinent that most recently existed as a part of the split of the Pangaean supercontinent in the late Mesozoic

These extinctions within the Triassic and at its end allowed the dinosaurs to expand into many niches that had become unoccupied. Dinosaurs became increasingly dominant, abundant and diverse, and remained that way for the next 150 million years. The true "Age of Dinosaurs" is the Jurassic and Cretaceous, rather than the Triassic.

See also

• Geologic timescale
• List of fossil sites (with link directory)
• Paleorrota (Triassic place in Brazil)

Notes

1. ^ http://de.wikipedia.org/wiki/Bild:Sauerstoffgehalt-1000mj.svg
2. ^ http://en.wikipedia.org/wiki/Image:Phanerozoic_Carbon_Dioxide.png
3. ^ http://en.wikipedia.org/wiki/Image:All_palaeotemps.png
4. ^ McElwain, J. The geologic time scale is a chronologic schema (or idealized Model) relating Stratigraphy to time that is used by Geologists and other This is a worldwide list of important and/or well-known localities where Fossils have been found The Geopark of Paleorrota (Paleoroute in English) is located in the center of the state of the Rio Grande do Sul in Brazil |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld C. ; Punyasena, S. W. (2007). "Mass extinction events and the plant fossil record". Trends in Ecology & Evolution 22 (10): 548-557. doi:10.1016/j.tree.2007.09.003. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
5. ^ ^{a b} Retallack GJ Veevers JJ & Morante R (1996). "Global coal gap between Permian–Triassic extinctions and middle Triassic recovery of peat forming plants". GSA Bulletin 108 (2): 195–207.  
6. ^ Payne, J. L. ; Lehrmann, D. J. ; Wei, J. ; Orchard, M. J. ; Schrag, D. P. ; Knoll, A. H. (2004). "Large Perturbations of the Carbon Cycle During Recovery from the End-Permian Extinction". Science 305 (5683): 506. doi:10.1126/science.1097023. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
7. ^ Lecture 10 - Triassic: Newark, Chinle
8. ^ Stanley, 452-3.
9. ^ Stanley, 452-3.
10. ^ Tanner LH, Lucas SG & Chapman MG (2004). "Assessing the record and causes of Late Triassic extinctions". Earth-Science Reviews 65 (1-2): 103-139. doi:10.1016/S0012-8252(03)00082-5. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
11. ^ Ruben, J. A. , and Jones, T. D. (2000). "Selective Factors Associated with the Origin of Fur and Feathers". American Zoologist 40 (4): 585-596. doi:10.1093/icb/40.4.585. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
12. ^ Holser WT Schonlaub H_P,Moses AJr Boekelmann K Klein P Magaritz MOrth CJ Fenninger A Jenny C Kralik M Mauritsch EP Schramm J_M Sattagger K Schmoller R 1989 A unique geochemical record at the Permian/Triassic boundary. Nature 337; 39, on p42
13. ^ Knauth LP 1998 Salinity history of the earth's early ocean, Nature 395; 554-555.
14. ^ Dott, R. H. and Batten, R. L. (1971) Evolution of the Earth, 4th ed. McGraw Hill, NY.
15. ^ Hosher WT Magaritz M Clark D 1987 Events near the Permian-Triassic boundary. Mod. Geol. 11; 155-180, on p173-174.
16. ^ Florin R (1963) The distribution of Conifer and Taxad genera in time and space. Acta Horti Bergiani. 20, 121-312.
17. ^ Melville R (1966) Continental drift, Mesozoic continents and the migrations of the angiosperms. Nature 211, 116.
18. ^ Darlington PJ (1965) Biogeography of the southern end of the world. Harvard University Press, Cambridge Mass. , on p168.
19. ^ Retallack GJ (1995) Permian -Triassic life crises on land. Science 267, 77-79.
20. ^ Eshet Y Rampino MR (1995) Fungal event and palynological record of ecological crises and recovery across Permian-Triassic boundary. Geology 23, 967-970, on p969.
21. ^ Retallack GJ Veevers JJ Morante R (1996) Global coal gap between Permian-Triassic extinctions and middle Triassic recovery of peat forming plants (review). Geological Society Am. Bull. 108, 195-207.
22. ^ Weesner FM (1960) Evolution biology of termites. Annual Review of Entomology. 5; 153-170.
23. ^ Tilyard RJ (1937) Kansas Permian insects. . Part XX the cockroaches, or order BlattariaI, II Am. Journal of Science 34; 169-202, 249-276.
24. ^ Retallack GJ Veevers JJ Morante R (1996) Global coal gap between Permian-Triassic extinctions and middle Triassic recovery of peat forming plants (review). Geological Society Am. Bull. 108, 195-207, on p196.
25. ^ Godfrey HCJ (1994) Parasitoid's Behavioral and Evolutionary Ecology. Princeton University Press, Princeton.
26. ^ Retallack G (1997) Paleosols in the upper Narrabeen group of New South Wales as evidence of early Triassic paleoenvironments without exact modern analogs (review) Australian Journal of Earth Sciences 44; 185-281.
27. ^ Nomade et al. ,2007 Palaeogeography, Palaeoclimatology, Palaeoecology 244, 326-344.
28. ^ Marzoli et al. , 1999, Science 284. Extensive 200-million-year-old continental flood basalts of the Central Atlantic Magmatic Province, pp. 618-620.
29. ^ Hodych & Dunning, 1992.
30. ^ No Significant Nonmarine Carnian-Norian (Late Triassic) Extinction Event: Evidence From Petrified Forest National Park

References

• Emiliani, Cesare, 1992, Planet Earth : Cosmology, Geology and the Evolution of Life and Environment
• Ogg, Jim; June, 2004, Overview of Global Boundary Stratotype Sections and Points (GSSP's) [1] Accessed April 30, 2006
• Stanley, Steven M. Cesare Emiliani ( 8 December 1922 - 20 July 1995) was an Italian-American scientist considered one of the greatest Geologists and Earth System History. New York: W. H. Freeman and Company, 1999. ISBN 0-7167-2882-6
• van Andel, Tjeerd, (1985) 1994, New Views on an Old Planet : A History of Global Change, Cambridge University Press

External links

• Overall introduction
• 'The Triassic world'
• Douglas Henderson's illustrations of Triassic animals
• Paleofiles page on the Triassic extinctions
• Examples of Triassic Fossils