Triassic extinctions

global climate change and biotic turnover that occurred during the Carnian or early Late Triassic

Younginiformes is a potential group of diapsid reptiles known from the Permian–Triassic of Africa. It has been used as a replacement for the more problematically-defined "Eosuchia". Younginiforms were historically suggested to be lepidosauromorphs, but are now regarded as basal non-saurian neodiapsids. Some younginiforms like Hovasaurus and Acerosodontosaurus are thought to have had an amphibious lifestyle, while others like Kenyasaurus, Thadeosaurus, and younginids were probably terrestrial.

Sphenophyllales is an extinct order of articulate land plants and a sister group to the present-day Equisetales (horsetails). They are fossils dating from the Devonian to the Triassic. They were common during the Late Pennsylvanian to Early Permian, with most of the fossils coming from the Carboniferous period.

Lystrosauridae is a family of dicynodont therapsids from the Permian and Triassic time periods. It includes two genera, Lystrosaurus and Kwazulusaurus. Kwazulusaurus includes a single species, K. shakai, from the Late Permian of South Africa and Lystrosaurus includes many species from the Late Permian and Early Triassic of South Africa, India, and Antarctica.

Eosuchia is a proposed order of extinct diapsid reptiles comprising taxa from the Permian and Triassic. Eosuchia was initially defined to include all "thecodontian" reptiles which did not have an antorbital fenestra but did retain tabulars, postparietals, and a large pineal foramen (Broom, 1914). Broom coined the term as a new suborder for Youngina.

Tanystropheidae is an extinct family of archosauromorph reptiles that lived throughout the Triassic Period, often considered to be "protorosaurs". They are characterized by their long, stiff necks formed from elongated cervical vertebrae with very long cervical ribs. Members of the group include both terrestrial and aquatic forms. While some tanystropheids were small lizard-like animals, other tanystropheids such as Tanystropheus were large animals that had necks that were several meters long, longer than the rest of their bodies.

Orthocerida, from Ancient Greek ὀρθός (orthós), meaning "straight", and κέρας (kéras), meaning "horn", also known as the Michelinocerida, is an order of extinct orthoceratoid cephalopods that lived from the Early Ordovician () possibly to the Late Triassic (). The Eocene fossil Antarcticeras is sometimes considered a descendant of the orthocerids although this is disputed. They were most common however from the Ordovician to the Devonian.

thumb|left|240px|An impression of Ceresiosaurus eating a small aquatic animal

Mastodonsauridae is a family of capitosauroid temnospondyls. Fossils belonging to this family have been found in North America, Greenland, Europe, Asia, and Australia. The family Capitosauridae is synonymous with Mastodonsauridae.

Lydekkerinidae is a family of stereospondyl temnospondyls that lived in the Early Triassic period. During this time period, lydekkerinids were widely distributed, with putative remains reported from Russia, Greenland, India, South Africa, Madagascar, Australia, and Antarctica. In contrast to most other stereospondyls, lydekkerinids were relatively small-bodied (most with skulls less than 10 cm in length). The type genus is Lydekkerina, the namesake of the family and the best-known lydekkerinid.

The Peltaspermales are an extinct order of seed plants, often considered "seed ferns". They span from the Late Carboniferous to the Early Jurassic or the Jurassic-Cretaceous Boundary. It includes at least one valid family, Peltaspermaceae, which spans from the Permian to Early Jurassic, which is typified by a group of plants with Lepidopteris leaves, Antevsia pollen-organs, and Peltaspermum ovulate organs, though the family now also includes other genera like Peltaspermopsis, Meyenopteris and Scytophyllum. Along with these, two informal groups (the "Supaioids" and the "Comioids") of uncertain

Baurioidea is a superfamily of therocephalian therapsids. It includes advanced therocephalians such as Regisaurus and Bauria. The superfamily was named by South African paleontologist Robert Broom in 1911. Bauriamorpha, named by D. M. S. Watson and Alfred Romer in 1956, is a junior synonym of Baurioidea.

Thalattosauroidea is a superfamily of thalattosaurs, a Triassic group of marine reptiles. It was named in 1904 by paleontologist John Campbell Merriam to include the genus Thalattosaurus from California. Thalattosauroids are one of two groups of Thalattosauria, the other being Askeptosauroidea. Thalattosauroids make up the "traditional" thalattosaurs with large downturned snouts, short necks, and long, paddle-like tails.

Dipteridae is an extinct family of prehistoric lungfishes which lived in the Devonian period.

Capitosauria is an extinct group of large temnospondyl amphibians with simplified stereospondyl vertebrae. Mainly living as piscivores in lakes and rivers, the Capitosauria and its sister taxon Trematosauria were the only major labyrinthodonts that existed during the Mesozoic in ecological niches broadly similar to those of modern crocodiles, and some grew to very large sizes. At 6 meters in length, the Mid-Triassic Mastodonsaurus giganteus is not only thought to have been the largest capitosaur, but possibly also the largest amphibian to have lived. The latest known remains are from the Rhaet

Gomphodontosuchinae is a subfamily of Triassic traversodontid cynodonts. It includes the genera Gomphodontosuchus (the type genus), Exaeretodon, Santagnathus, Siriusgnathus, Menadon, Proexaeretodon, Protuberum, Ruberodon and Scalenodontoides.

Whiteiidae is an extinct family of prehistoric coelacanth fishes which lived during the Triassic period. Torino, Soto, and Perea (2021) did not support this clade as it was not found to be monophyletic in their analysis, however, Ferrante and Cavin (2025) found the family to be a valid clade.

Orthoceratoidea, from Ancient Greek ὀρθός (orthós), meaning "straight", and κέρας (kéras), meaning "horn", is a major subclass of nautiloid cephalopods. Members of this subclass usually have orthoconic (straight) to slightly cyrtoconic (curved) shells, and central to subcentral siphuncles which may bear internal deposits. Orthoceratoids are also characterized by dorsomyarian muscle scars (a small number of large scars concentrated at the top of the body chamber), extensive cameral deposits, and calciosiphonate connecting rings with a porous and calcitic inner layer.

Ceratitidae is an extinct family of ammonite cephalopods.

Askeptosauridae is a family of thalattosaurs within the superfamily Askeptosauroidea. Fossils have been found from Italy, Switzerland, and China. Askeptosaurids are distinguished from other thalattosaurs by their long necks and narrow skulls.

Chiropteris is an extinct genus of plants that existed from the Early Permian (Sakmarian stage) to the Late Jurassic (?Oxfordian stage, maybe latter).

Strophomenata is an extinct class of brachiopods in the subphylum Rhynchonelliformea.

Askeptosauroidea is a superfamily of thalattosaurs, a Triassic group of marine reptiles. Askeptosauroidea is one of two major subgroups of Thalattosauria, the other being Thalattosauroidea. It includes the family Askeptosauridae and a more basal form called Endennasaurus.