Late Cretaceous extinctions

extinction event ending the Mesozoic Era

Semionotiformes is an order of ray-finned fish known from the Middle Triassic (Anisian) to the Late Cretaceous (Maastrichtian). Their closest living relatives are gars (Lepisosteidae), with both groups belonging to the clade Ginglymodi within the Holostei. The group includes both freshwater (Semionotidae) and marine (Callipurbeckiidae, Macrosemiidae) adapted forms. Many members of the family Macrosemiidae (which are usually included in Semionotiformes but sometimes placed in their order), had elongated dorsal fins, often associated with an adjacent area of skin which was free of scales. These

left|thumb|Life restoration of Muraenosaurus Cryptoclididae is a family of medium-sized plesiosaurs that existed from the Middle Jurassic to the Early Cretaceous. They had long necks, broad and short skulls and densely packed teeth. They fed on small soft-bodied preys such as small fish and crustaceans. The earliest members of the family appeared during the early Bajocian, and they represented the dominant group of long-necked plesiosaurs during the latter half of the Jurassic.

thumb|Pholidosaurus|Pholidosaurus purbeckensis fossil.

Protosuchia is a group of extinct Mesozoic crocodyliforms. They were small in size (~1 meter in length) and terrestrial. In phylogenetic terms, Protosuchia is considered an informal group because it is a grade of basal crocodyliforms, not a true clade.

Triconodontidae is an extinct family of small, carnivorous mammals belonging to the order Eutriconodonta, living in what would become Asia, Europe, North America and probably also Africa and South America during the Jurassic through Cretaceous periods at least from 190–66 mya.

asteroid impact hypothesis as cause of the Cretaceous–Paleogene extinction

Ammonitina comprises a diverse suborder of ammonite cephalopods that lived during the Jurassic and Cretaceous periods of the Mesozoic Era. They are excellent index fossils, and it is often possible to link the rock layer in which they are found to specific geological time periods.

anoxic extinction events in the Cretaceous period, occurring at 91.5 ± 8.6 Ma

Thylacocephala (from the Greek or ', meaning "pouch", and or ' meaning "head") is an extinct group of mandibulate arthropods, that are generally regarded as a kind of crustacean, though their exact position within this group is uncertain. As a class they have a short research history, having been erected in the early 1980s.

Gobiconodontidae is a family of extinct mammals that ranged from the mid-Jurassic to the early Late Cretaceous, though most common during the Early Cretaceous. The Gobiconodontids form a diverse lineage of carnivorous non-therian mammals, and include some of the best preserved Mesozoic mammal specimens.

Uruguaysuchidae is a family of notosuchian crocodyliforms that lived in South America and Africa during the Cretaceous period. It was formally defined under the PhyloCode in 2024 as "the most inclusive clade containing Uruguaysuchus aznarezi but not Baurusuchus pachecoi, Peirosaurus torminni, Mahajangasuchus insignis, Notosuchus terrestris, and Crocodylus niloticus." Below is a modified cladogram that depicts the preferred reference phylogeny, chosen from Fernández Dumont et al. (2020):

Brachyphyllum (meaning "short leaf") is a form genus of fossil coniferous plant foliage. Plants of the genus have been variously assigned to several different conifer groups including Araucariaceae and Cheirolepidiaceae. They are known from around the globe from the Late Carboniferous to the Late Cretaceous periods.

Djadochtatheriidae is a family of fossil mammals within the extinct order Multituberculata. Remains are known from the Upper Cretaceous of Central Asia. These animals lived during the Mesozoic, also known as the "age of the dinosaurs". This family is part of the suborder of Cimolodonta. The taxon Djadochtatheriidae was named by Zofia Kielan-Jaworowska and Jørn Hurum in 1997.

Polyglyphanodontia, also known as the Borioteiioidea, is an extinct clade of Cretaceous lizards. Polyglyphanodontians were the dominant group of lizards in North America and Asia during the Late Cretaceous.

Sphagesauridae is a Gondwanan family of mesoeucrocodylians that lived during the Late Cretaceous. It was a clade of terrestrial crocodilians that evolved very mammal-like teeth and jaws. Both Sphagesaurus and Adamantinasuchus are known from the Turonian to Santonian of Brazil.

Stagodontidae is an extinct family of carnivorous metatherian mammals that inhabited North America and Europe during the late Cretaceous, and possibly to the Eocene in South America.

The Inoceramidae are an extinct family of bivalves ("clams") in the Class Mollusca. Fossils of inoceramids are found in marine sediments of Permian to latest Cretaceous in age. Inoceramids tended to live in upper bathyal and neritic environments. Many species of inoceramid are found all over the world, demonstrating the wide distribution of their preferred ecosystems, and possibly long-lived planktotrophic larvae. Despite their wide distribution, the pace of evolution of inoceramids was great, with species ranges commonly averaging 0.2-0.5 Ma.

Asioryctitheria ("Asian digging beasts") is an extinct order of early eutherians.

Aegeridae is a family of fossil prawns, one of the earliest Mesozoic shrimp families. It contains the genera Aeger, Acanthochirana, Anisaeger and Distaeger. The main diagnostic character of Aegeridae is the presence of numerous spines or thin setae on the third maxilliped.

Caturidae is an extinct family of predatory amiiform ray-finned fish, being the sister-group to the extant family Amiidae. Though their body form is very different than the modern bowfin, a number of features in the skull point towards a close relationship between the groups. Members of the family were generally larger fish that lived within more coastal marine environments along with freshwater environments near the coast. In these environments, caturids would have fed on a variety of prey items, hunting them similarly to fish like gars and barracudas. The earliest members of the family appea

Palaeoctopodidae is an extinct family of incirrate octopuses that lived during the Late Cretaceous. It includes two genera, Keuppia and Palaeoctopus.

Gobiosuchidae is a family of Cretaceous crocodyliforms known from Mongolia and Spain.

Acanthoceratidae is an extinct family of acanthoceratoid cephalopods in the order Ammonitida, known from the Upper Cretaceous. The type genus is Acanthoceras.

Acanthoceratoidea, formerly Acanthocerataceae, is a superfamily of Upper Cretaceous ammonoid cephalopods belonging to the order Ammonitida, and comprising some 10 or so families.

The Phylloceratina are a suborder of ammonoid cephalopods, belonging to the Ammonitida, whose range extends from the Lower Triassic to the Upper Cretaceous. Shells of the Phylloceratina are generally smooth with small to large umbilici and complex sutures with leaf-like phylloid saddle endings and lobes with thornlike projections.

Carpopenaeus is an extinct genus of prawn, which existed during the Upper Jurassic and Cretaceous periods. It contains three species.

Gobiguania is an extinct clade of iguanian lizards from the Late Cretaceous. All known gobiguanians are endemic to the Gobi Desert of Mongolia. Gobiguania was given a phylogenetic definition by Jack Conrad and Mark Norell in 2007 as all taxa more closely related to Anchaurosaurus gilmorei than to Iguana iguana (the green iguana), Crotaphytus collaris (the common collared lizard), or Agama agama (the common agama). According to Conrad and Norell's phylogenetic analysis, Gobiguania includes Anchaurosaurus as well as several other Late Cretaceous lizards such as Ctenomastax, Temujinia, Saichangur

Comahuesuchidae is a family of notosuchian crocodyliforms. Constructed in 1991, it includes the genera Comahuesuchus and Anatosuchus. Among the characteristics that are unique to this family is an external naris that is inset into the tip of the snout. There is also a diastema, or gap between the teeth, at the tip of the upper and lower jaws. Both Anatosuchus and Comahuesuchus have maxillary tooth rows in the upper jaw that extend out and over the dentary tooth rows of the lower jaw.

Lytoceratina is a suborder of Jurassic and Cretaceous ammonites that produced loosely coiled, evolute and gyroconic shells in which the sutural element are said to have complex moss-like endings.

Sloanbaataridae is a family of fossil mammals within the extinct order Multituberculata. Remains are known from the Upper Cretaceous of Mongolia. These small herbivores lived during the "age of the dinosaurs". This family is part of the suborder Cimolodonta. The family Sloanbaataridae was named by Kielan-Jaworowska, Z. in 1974.