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] 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.[3] The earliest neosuchian is suggested to be the Early JurassicCalsoyasuchus, which lived during the Sinemurian and Pliensbachian stages in North America. It is often identified as a member of Goniopholididae,[4] though this is disputed, and the taxon may lie outside Neosuchia, which places the earliest records of the group in the Middle Jurassic.[3]
Characteristics
Members of Neosuchia have a wide diversity of skull shapes. Several groups convergently evolved elongate gharial-like skulls, which makes determining phylogenetic relationships of these taxa problematic.[5]
Phylogeny
Below is a cladogram showing the phylogenetic relationships of neosuchians from Buscalioni et al., 2011:[6]
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]
^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.