Chordate superorders

The Lepidosauria (, from Greek meaning scaled lizards) is a superorder of reptiles, containing the orders Squamata and Rhynchocephalia. Squamata, comprising lizards and snakes, contains over 9,000 species, making it by far the most species-rich and diverse order of non-avian reptiles in the present day. Rhynchocephalia was a formerly widespread and diverse group of reptiles in the Mesozoic Era. However, it is represented by only one living species: the tuatara (Sphenodon punctatus), a superficially lizard-like reptile native to New Zealand.

Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic diapsid reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became extinct at the end of that period. The plesiosaurs would continue to diversify until the end of the Mesozoic, when they became extinct as part of the end-Cretaceous mass extinction. Sauropterygians are united by a radical adaptation of their pectoral girdle, adapted to support powerful flipper strokes. Some later sauropterygians, such as the plio

Crocodylomorpha is a group of pseudosuchian archosaurs that includes the crocodilians and their extinct relatives. They were the only members of Pseudosuchia to survive the end-Triassic extinction. Extinct crocodylomorphs were considerably more ecologically diverse than modern crocodilians. The earliest and most primitive crocodylomorphs are represented by "sphenosuchians", a paraphyletic assemblage containing small-bodied, slender forms with elongated limbs that walked upright, which represents the ancestral morphology of Crocodylomorpha. These forms persisted until the end of the Jurassic. D

Ichthyopterygia ("fish flippers") was a designation introduced by Sir Richard Owen in 1840 to designate the Jurassic ichthyosaurs that were known at the time, but the term is now used more often for both true Ichthyosauria and their more primitive early and middle Triassic ancestors.

Galeomorphi is a superorder of sharks. They are sometimes called galea or galean sharks. There are about 300 living species in 23 families. Galean sharks are divided into four orders: the Heterodontiformes, Orectolobiformes, Lamniformes, and Carcharhiniformes. The extinct, enigmatic Synechodontiformes are presently placed by some authors in the galeomorphs, but their taxonomic position still remains uncertain.