Thalattosuchian

Thalattosuchia Temporal range: 195–125 Ma PreЄ Є O S D C P T J K Pg N Sinemurian - early Aptian
Dakosaurus, a metriorhynchid.
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Neosuchia
Suborder:	†Thalattosuchia Fraas, 1901
Families
†Metriorhynchidae †Teleosauridae

Thalattosuchia is the name given to a clade of 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.

The term Thalattosuchia was coined by Fraas in 1901. Various authors considered Thalattosuchia an infraorder or a suborder within "Mesosuchia". However, the term "Mesosuchia" is a paraphyletic group, and as such is no longer used. For consistency, the Thalattosuchia are here placed at suborder rank, although the order that contains it is unnamed.

Since Buffetaut (1982) demonstrated the shared characteristics of the early forms of Metriorhynchidae and Teleosauridae, Thalattosuchia has consisted of these two families.

Some of the early members of Teleosauridae have been discovered in non-marine deposits. The systematics of the genus Pelagosaurus are confused, with differencing topologies placing it as either a teleosaurid, or as the sister taxon to a Teleosauridae + Metriorhynchidae clade. Others considered Pelagosaurus to be a basal metriorhynchid.