"Mesosuchia" is an obsolete name for a group of terrestrial, semi-aquatic, or fully aquatic crocodylomorph reptiles. The marine crocodile Metriorhynchus had paddle-like forelimbs, Dakosaurus andiniensis had a skull that was adapted to eat large sea reptiles, and Shamosuchus was adapted for eating molluscs and gastropods. Shamosuchus also looked like modern crocodiles and was very closely related to their direct ancestor.
The "Mesosuchia" were formerly placed at Suborder rank as within Crocodylia. The "first" crocodiles were placed within their own suborder, Protosuchia; whilst extant species where placed within Suborder Eusuchia (meaning 'true crocodiles'). Mesosuchia were the crocodylians "in between".But it is no longer regarded as genuine because it belongs to a paraphyletic group. It is replaced by its phylogenetic equivalent Mesoeucrocodylia, which contains the taxa herein, the Crocodylia, and some allied forms more recently discovered.
The "Mesosuchia" was composed as: