Early Cretaceous extinctions

Temnospondyli (from Greek τέμνειν, temnein 'to cut' and σπόνδυλος, spondylos 'vertebra') or temnospondyls is a diverse ancient order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carboniferous, Permian and Triassic periods, with fossils being found on every continent. A few species continued into the Jurassic and Early Cretaceous periods, but all had gone extinct by the Late Cretaceous. During about 210 million years of evolutionary history, they adapted to a wide range of habitats, including freshwater, terrestrial, and even coastal mar

Thalattosuchia is a clade of mostly marine crocodylomorphs from the Early Jurassic to the Early Cretaceous that had a cosmopolitan distribution. They are colloquially referred to as marine crocodiles or sea crocodiles, though they are not members of Crocodilia and records from Thailand and China suggest that some members lived in freshwater. The clade contains two major subgroupings, the Teleosauroidea and Metriorhynchoidea. Teleosauroids are not greatly specialised for oceanic life, with back osteoderms similar to other crocodyliformes. Within Metriorhynchoidea, the Metriorhynchidae displayed

thumb|Life restoration of members of the Metriorhynchinae compared to a human Metriorhynchidae is an extinct family of specialized, aquatic metriorhynchoid crocodyliforms from the Middle Jurassic to the Early Cretaceous period (Bajocian to early Aptian) of Europe, North America and South America. The name Metriorhynchidae was coined by the Austrian zoologist Leopold Fitzinger in 1843. The group contains two subfamilies, the Metriorhynchinae and the Geosaurinae. They represent the most marine adapted of all archosaurs.

Morganucodonta ("Glamorgan teeth") is an extinct order of basal Mammaliaformes, a group including crown-group mammals (Mammalia) and their close relatives. Their remains have been found in Southern Africa, Western Europe, North America, India and China. The morganucodontans were probably insectivorous and nocturnal, though like eutriconodonts some species attained large sizes and were carnivorous. Nocturnality is believed to have evolved in the earliest mammals in the Triassic (called the nocturnal bottleneck) as a specialisation that allowed them to exploit a safer, night-time niche, while mo

Tritylodontidae ("three-knob teeth", named after the shape of their cheek teeth) is an extinct family of small to medium-sized, highly specialized mammal-like cynodonts, with several mammalian traits including erect limbs, endothermy, and some details of the skeleton. They were the last-known family of the non-mammaliaform synapsids, persisting into the Early Cretaceous.

Brachyopoidea is a superfamily of temnospondyls that lived during the Mesozoic. It contains the families Brachyopidae and Chigutisauridae. The earliest records of brachyopids are from the Lower Triassic in Australia. The latest-surviving member of the superfamily is the chigutisaurid Koolasuchus from the Early Cretaceous of Australia.

Ichthyosauridae is an extinct family of thunnosaur ichthyosaurs from the latest Triassic and Early Jurassic (Rhaetian to Pliensbachian stages) of Europe, and possibly also from the middle Early Cretaceous (Hauterivian or Barremian stage) of Iraq. Named by Charles Lucien Bonaparte, in 1841, it is usually thought to contain a single genus, Ichthyosaurus, which is known from several species from the Early Jurassic. In 2013, Fischer et al. named and described Malawania anachronus from the middle Early Cretaceous of Iraq. It was found to share several synapomorphies with the type species of this fa

Stereospondylomorpha is a clade of temnospondyls. It includes the superfamily Archegosauroidea and the more diverse group Stereospondyli. Stereospondylomorpha was first proposed by Yates and Warren (2000), who found Archegosauroidea and Stereospondyli to be sister taxa in their phylogenetic analysis. A similar clade is Archegosauriformes, named by Schoch and Milner (2000), which includes Stereospondyli and some Permian temnospondyls that are similar in appearance to stereospondyls, including the archegosauroids. However, according to Schoch and Milner's phylogeny, Archegosauroidea is a paraphy

Eobaataridae is a family of fossil mammals within the order Multituberculata. Remains are known from the Lower Cretaceous of Europe and Asia. They are among the most derived representatives of the informal suborder "Plagiaulacida", and closely related to Cimolodonta. Most eobaatarids are only known from isolated teeth, though several reasonably complete members are known, including Sinobaatar and Jeholbaatar. The body of Sinobaatar is generalised, while Jeholbaatar displays clear adaptations for scansoriality (climbing) due to its elongated digits. Due to the morphology of the cheek teeth, Eob

Coptoclavidae is an extinct family of aquatic beetles in the suborder Adephaga. The Coptoclavidae lived from the Late Triassic to the Early Cretaceous. Coptoclavidae is a member of the adephagan clade Dytiscoidea, which contains living aquatic beetles, including living predatory diving beetles (Dytiscidae). Coptoclavids are thought to have hunted on the water surface, similar to whirligig beetles (Gyrinidiae), with prey likely including small fish and larval amphibians. Suggested reasons for their extinction to include the rise of teleost fish, or competition with Gyrinidae and Dytiscidae, whi

right|thumb|Arenaerpeton|Arenaerpeton supinatus (specimen AM F125866) from the [[Sydney Basin]]

thumb|160px|right|Fossil specimen of Jeholodens jenkinsi, [[National Museum of Nature and Science, Tokyo]]

Coxoplectoptera or "chimera wings" is an extinct order of stem-group mayflies containing one family, Mickoleitiidae. Together with mayflies (Ephemeroptera), Coxoplectoptera are assigned to the clade Heptabranchia.

Paurodontidae is a family of Late Jurassic to Early Cretaceous mammals in the order Dryolestida. Remains of paurodontids have been found in the United States, Britain, Portugal, and Tanzania. The group likely represents a paraphyletic group of basal non dryolestid dryolestidans. Paurodon has been suggested to have been a specilast feeder on earthworms due to the morphology of its teeth closely resembling that of the golden mole genus Amblysomus.

Lycoptera is an extinct genus of fish that lived from Lower Cretaceous, Barremian to Aptian in present-day China, North Korea, Mongolia and Siberia. Although there is record from Jurassic Formation in Siberia, its age remains questionable. It is known from abundant fossils representing sixteen species, which serve as important index fossil used to date geologic formations in China. Along with the genus Peipiaosteus, Lycoptera has been considered a defining member of the Jehol Biota, a prehistoric ecosystem famous for its feathered dinosaurs, which flourished for 20 million years during the Ear

Metriorhynchoidea is an extinct superfamily of thalattosuchian crocodyliforms from the Early Jurassic to the Early Cretaceous (Toarcian - Valanginian, possibly as late as early Aptian) of Europe, North America and South America. Metriorhynchids are fully aquatic crocodyliforms. Named by Fitzinger, in 1843, it contains the basal taxa like Teleidosaurus, Zoneait and Eoneustes and the family Metriorhynchidae. An unnamed taxon is known from Chile.

Ophthalmosaurinae is an extinct subfamily of ophthalmosaurid thunnosaur ichthyosaurs from the Middle Jurassic to the late Early Cretaceous (Bajocian - Albian) of Europe, North America and South America. Currently, the oldest and the basalmost, known ophthalmosaurine is Mollesaurus from the early Bajocian of Argentina. Ophthalmosaurines were characterized by a large extracondylar area of the basioccipital in the form of a thick and concave peripheral band, posterodistally deflected ulnar facet of the humerus, large ulna with concave and edgy posterior surface and ischiopubis with obturator fora

Limnarchia is a clade of temnospondyls. It includes the mostly Carboniferous-Permian age Dvinosauria and the mostly Permian-Triassic age Stereospondylomorpha. The clade was named in a 2000 phylogenetic analysis of stereospondyls and their relatives. Limnarchia means "lake rulers" in Greek, in reference to their aquatic lifestyles and long existence over a span of approximately 200 million years from the Late Carboniferous to the Early Cretaceous. In phylogenetic terms, Limnarchia is a stem-based taxon including all temnospondyls more closely related to Parotosuchus than to Eryops. It is the si

Pinheirodontidae is a poorly known family of fossil mammals which belong to the informal suborder "Plagiaulacida" within the order Multituberculata. Remains are known from the Late Jurassic to Early Cretaceous of Europe (predominantly Portugal and Spain), but are so far restricted to isolated teeth, as well as a single lower jaw. The family Pinheirodontidae was named by Hahn G. and Hahn R. in 1999, after the locality of Porto Dinheiro, in central west Portugal.

The Amphidontidae are a family of extinct mammals from the Early Jurassic to the Early Cretaceous, belonging to the eutriconodonts. It contains most of the species previously belonged to Amphilestidae.

Tinodontidae is an extinct family of actively mobile mammals, endemic to what would now be North America, Asia, Europe, and Africa during the Jurassic and Cretaceous periods.

Protosuchidae is a family of basal crocodyliform reptiles that lived from the Late Triassic to the Late Cretaceous. This family should not be confused with Protosuchia, which is an informal evolutionary grade of primitive crocodyliforms

Bidentalia is a group of dicynodont therapsids. Bidentalia was one of the first names used to describe dicynodonts; the group was established in 1876, while the name "bidentals" dates back as far as 1845. With the increasing prominence of phylogenetics, the group was redefined as a clade in 2009. Bidentalia is now considered a stem-based taxon that includes all taxa more closely related to Aulacephalodon bainii and Dicynodon lacerticeps than Emydops arctatus.

Perisphinctoidea, formerly Perisphinctaceae, is a superfamily of Middle Jurassic (Bajocian) to Lower Cretaceous (Barremian) ammonites, commonly with evolute shells with strong ribbing that typically divides about mid flank before crossing the venter.

Rhachitomi is a group of temnospondyl amphibians that includes all temnospondyls except edopoids and dendrerpetontids. It was established as a clade name by German paleontologist Rainer R. Schoch in 2013, although the name had first been established in 1919 by British paleontologist D. M. S. Watson to encompass an evolutionary grade of temnospondyls leading to the group Stereospondyli. American paleontologist Alfred Romer used the term in a similar sense, grouping most Permian and Triassic temnospondyls under Rhachitomi. A similar name that appeared earlier in the scientific literature is Rach

Albionbaataridae is a family of small, extinct mammals within the order Multituberculata. Fossil remains are known from the Upper Jurassic and Lower Cretaceous of Europe and Asia. These herbivores lived their obscure lives during the Mesozoic, also known as the "age of the dinosaurs." They were among the more derived representatives of the informal suborder "Plagiaulacida". The taxon Albionbaataridae was named by Kielan-Jaworowska Z. and Ensom P.C. in 1994.

Volaticotherini is a clade of eutriconodont mammals from the Mesozoic. In addition to the type genus Volaticotherium, it includes the genera Argentoconodon, Ichthyoconodon, and potentially Triconolestes.

Eutemnospondyli (meaning "true Temnospondyli") is a clade of temnospondyl amphibians that includes most temnospondyls except edopoids. Eutemnospondyli was named by German paleontologist Rainer R. Schoch in 2013. He defined it as a stem-based taxon including all temnospondyls more closely related to Stereospondyli than to Edopoidea. In his phylogenetic analysis, Eutemnospondyli included dendrerpetontids and a clade he referred to as Rhachitomi. Rhachitomi is defined to include four major and well-supported clades of temnospondyls: Dvinosauria, Eryopidae, Stereospondyli and a clade formed by Zat