Neosuchia is a clade within Mesoeucrocodylia that includes all modern extant crocodilians and their closest fossil relatives.[1] It is defined as the most inclusive clade containing all crocodylomorphs more closely related to Crocodylus niloticus (the Nile Crocodile) than to Notosuchus terrestris.[2] Neosuchia is very diverse and may be polyphyletic, as the clade has undergone many revisions since it was first named in 1988.[3] Members of Neosuchia generally share a crocodilian-like bodyform adapted to freshwater aquatic life, as opposed to the terrestrial habits of more basal crocodylomorph groups.[4] The earliest neosuchian is suggested to be the Early JurassicCalsoyasuchus, which lived during the Sinemurian and Pliensbachian stages, often identified as a member of Goniopholididae,[5] though this is disputed, and the taxon may lie outside Neosuchia, which places the earliest records of the group in the Middle Jurassic.[4]
A tooth notch between the maxilla and premaxilla is a basal characteristic of the Neosuchia, although it is lost in some more derived forms, most notably alligatorids.
In 2012, paleontologists Mario Bronzati, Felipe Chinaglia Montefeltro, and Max C. Langer conducted a broad phylogenetic analysis to produce supertrees of Crocodyliformes, including 184 species. The most parsimonious trees were highly resolved, meaning the phylogenetic relationships found in the analysis were highly likely. Below is a consensus tree from the study:[7]
^Benton, M. J. & Clark, J. M. (1998). Archosaur phylogeny and the relationships of the Crocodylia, p. 289-332. In Benton, M.J. (ed.), The Phylogeny and Classification of Tetrapods, Vol. 1 ., Clarendon Press, Oxford.
^Bronzati, M.; Montefeltro, F. C.; Langer, M. C. (2012). "A species-level supertree of Crocodyliformes". Historical Biology. 24 (6): 598–606. doi:10.1080/08912963.2012.662680. S2CID53412111.
