The Triassic is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic.
Cynodontia is a clade of eutheriodont therapsids that first appeared in the Late Permian, and extensively diversified after the Permian–Triassic extinction event. Mammals are cynodonts, as are their extinct ancestors and close relatives (Mammaliaformes), having evolved from advanced probainognathian cynodonts during the Late Triassic.
The Rhaetian is the latest age of the Triassic Period or the uppermost stage of the Triassic System. It was preceded by the Norian and succeeded by the Hettangian. The base of the Rhaetian lacks a formal GSSP, though candidate sections include Steinbergkogel in Austria and Pignola-Abriola in Italy. The end of the Rhaetian is more well-defined. According to the current ICS system, the Rhaetian ended 201.4 ± 0.2 Ma.
The Carnian is the lowermost stage of the Upper Triassic Series. It lasted from 237 to 227 million years ago (Ma). The Carnian is preceded by the Ladinian and is followed by the Norian. Its boundaries are not characterized by major extinctions or biotic turnovers, but a climatic event occurred during the Carnian and seems to be associated with important extinctions or biotic radiations. Another extinction occurred at the Carnian-Norian boundary, ending the Carnian age.
The Late Triassic is the third and final epoch of the Triassic Period in the geologic time scale, spanning the time between 237 Ma and 201.4 Ma. It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. The corresponding series of rock beds is known as the Upper Triassic. The Late Triassic is divided into the Carnian, Norian and Rhaetian ages.
Kuehneosaurus is an extinct genus of Late Triassic kuehneosaurid reptile known from the Late Triassic of the Penarth Group of southwest England and the Steinmergel Group of Luxembourg. Temperature at this stage and region would have ranged from 28 to 35 °C. It was named by P. L. Robinson in 1962 in honour of paleontologist Walther Kühn, and the type and only species is Kuehneosaurus latus. Measuring 72 centimetres long, it had "wings" formed from ribs which jutted out from its body by as much as 14.3 cm, connected by a membrane which allowed it to slow its descent when jumping from trees. It is a member of a family of extinct gliding reptiles, the Kuehneosauridae, within a larger living group the Lepidosauromorpha, which contain modern lizards and tuatara.
Probainognathia is one of the two major subgroups of the clade Eucynodontia, the other being Cynognathia. The earliest forms were carnivorous and insectivorous, though some groups eventually also evolved herbivorous diets. The earliest and most basal probainognathian is the Middle Triassic (Anisian) aged Lumkuia, from South Africa, though probainognathians would not become prominent until the mid Norian stage of the Late Triassic. Three groups survived the extinction at the end of Triassic: Tritheledontidae and Tritylodontidae, which both survived until the Jurassic—the latter even into the Cretaceous —and Mammaliaformes, which includes the mammals.
Machaeroprosopus is an extinct genus of mystriosuchin leptosuchomorph phytosaur from the Late Triassic of the southwestern United States. M. validus, once thought to be the type species of Machaeroprosopus, was named in 1916 on the basis of three complete skulls from Chinle Formation, Arizona. The skulls have been lost since the 1950s, and a line drawing in the original 1916 description is the only visual record of the specimen. Another species, M. andersoni, was named in 1922 from New Mexico, and the species M. adamanensis, M. gregorii, M. lithodendrorum, M. tenuis, and M. zunii were named in 1930. Most species have been reassigned to the genera Smilosuchus, Rutiodon, or Phytosaurus. Until recently, M. validus was considered to be the only species that has not been reassigned. Thus, Machaeroprosopus was considered to be a nomen dubium or "doubtful name" because of the lack of diagnostic specimens that can support its distinction from other phytosaur genera. However, a taxonomic revision of Machaeroprosopus, conducted by Parker et al. in 2013, revealed that UW 3807, the holotype of M. validus, is not the holotype of Machaeroprosopus, while the species Machaeroprosopus buceros, Machaeroprosopus being a replacement name, with a fixed type species, for Metarhinus, is the combinatio nova of the type species of the genu: Belodon buceros. Therefore, the name Pseudopalatus must be considered a junior synonym of Machaeroprosopus, and all species of the former must be reassigned to the latter. This revised taxonomy was already accepted in several studies, including Stocker and Butler (2013). Stocker and Butler (2013) also treated M. andersoni as a valid species, and not a junior synonym of Machaeroprosopus buceros as was previously suggested by Long and Murry (1995).
The Norian is a division of the Triassic Period. It has the rank of an age (geochronology) or stage (chronostratigraphy). It lasted from ~227 to 208.5 million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 2012.
Metapolygnathus is an extinct genus of platform conodonts.
Carnepigondolella is an extinct genus of conodonts of the Late Triassic of Italy or Canada.
Epigondolella is an extinct genus of conodonts in the family Gondolellidae.
Mazzaella is an extinct genus of Late Triassic ozarkodinid conodonts in the family Gondolellidae. They are found in mid-Julian sediments of the Tethys Ocean, including strata in Europe and Turkey.
Conodonts are an extinct class of animals whose feeding apparatuses called teeth or elements are common microfossils found in strata dating from the Stage 10 of the Furongian, the fourth and final series of the Cambrian, to the Rhaetian stage of the Late Triassic. These elements can be used alternatively to or in correlation with other types of fossils in the subfield of the stratigraphy named biostratigraphy.
Misikella is an extinct genus of conodonts.
The Pignola-Abriola section is a ~63 m long stratigraphic sequence of cherty limestones deposited in the Lagonegro Basin during the latest Norian and the early Rhaetian Stages. The main outcrop is on the western side of Mount Crocetta along the SP5 road connecting the villages of Pignola and Abriola. A smaller outcrop, overlapping the central part of the main section, is located near a former railway tunnel, few meters below the road level. The Pignola-Abriola section has been recently proposed as GSSP of the Rhaetian Stage.
Oncodella is an extinct genus of Late Triassic conodont. The genus was given the type species Oncodella idiodentica by Mosher (1968), on the basis of fossils from the Late Triassic of Austria. However, Mosher (1969) later revised the species name to Oncodella paucidentata, since identical fossils from the same area were previously given the name Hindeodella paucidentata by Mostler (1967).
Parvigondolella is an extinct genus of Late Triassic conodonts. The most common species in the genus, Parvigondolella andrusovi, is used as an index fossil for part of the Sevatian substage of the Norian stage. Kozur & Mock, 1991 named two additional species, P. rhaetica and P. vrielyncki. Moix et al. (2007) later argued that "Misikella" rhaetica was a species of Parvigondolella. In order to prevent having two different species with the same name within the genus, they renamed Kozur & Mock (1991)'s P. rhaetica to P. prorhaetica. However, this would be unnecessary if "Misikella" rhaetica was not related to Parvigondolella. Parvigondolella is typically considered a direct descendant of Mockina/Epigondolella bidentata.
Land vertebrate faunachrons (LVFs) are biochronological units used to correlate and date terrestrial sediments and fossils based on their tetrapod faunas. First formulated on a global scale by Spencer G. Lucas in 1998, LVFs are primarily used within the Triassic Period, though Lucas later designated LVFs for other periods as well. Eight worldwide LVFs are defined for the Triassic. The first two earliest Triassic LVFs, the Lootsbergian and Nonesian, are based on South African synapsids and faunal assemblage zones estimated to correspond to the Early Triassic. These are followed by the Perovkan and Berdyankian, based on temnospondyl amphibians and Russian assemblages estimated to be from the Middle Triassic. The youngest four Triassic LVFs, the Otischalkian, Adamanian, Revueltian, and Apachean, are based on aetosaur and phytosaur reptiles common in the Late Triassic of the southwestern United States.
