|Prestosuchus chiniquensis, an early suchian|
Suchia is a clade of archosaurs containing the majority of pseudosuchians. It includes crocodilians and their extinct relatives. It was defined as the least inclusive clade containing Aetosaurus ferratus, Rauisuchus tiradentes, Prestosuchus chiniquensis, Gracilisuchus stipanicicorum, and Crocodylus niloticus (the living Nile crocodile) by Nesbitt (2011). Generally the only pseudosuchians which are excluded from the group are the ornithosuchids, although at least one analysis classifies ornithosuchids as close relatives of erpetosuchids (which are usually considered suchians) and aetosaurs (which are suchians by definition of the group).
It was originally defined by Krebs in 1974. Paul Sereno provided a different definition, which included Gracilisuchus stipanicicorum, Aetosauria, Rauisuchia, Poposauridae, Crocodylomorpha, and all descendants of their common ancestor. Nesbitt (2011) redefined it as the least inclusive clade containing Aetosaurus ferratus, Rauisuchus tiradentes, Prestosuchus chiniquensis, and Crocodylus niloticus (the living Nile crocodile). Suchia, therefore, is a node-based taxon. It includes crocodylomorphs and more basal Triassic forms like aetosaurs and rauisuchians. Butler et al. (2011) found that Suchia includes Gracilisuchus, Turfanosuchus, Revueltosaurus, Aetosauria, Ticinosuchus, and paracrocodylomorphs.
Below is the cladogram originally identified by Krebs (1974) in his definition of Suchia:
- Ezcurra, Martín D.; Fiorelli, Lucas E.; Martinelli, Agustín G.; Rocher, Sebastián; Baczko, M. Belén von; Ezpeleta, Miguel; Taborda, Jeremías R. A.; Hechenleitner, E. Martín; Trotteyn, M. Jimena (11 September 2017). "Deep faunistic turnovers preceded the rise of dinosaurs in southwestern Pangaea". Nature Ecology & Evolution. 1 (10): 1477–1483. doi:10.1038/s41559-017-0305-5. ISSN 2397-334X.
- Nesbitt, S.J. (2011). "The Early Evolution of Archosaurs: Relationships and the Origin of Major Clades". Bulletin of the American Museum of Natural History. 352: 189. doi:10.1206/352.1. ISSN 0003-0090.
- Butler, R.J.; Brusatte, S.J.; Reich, M.; Nesbitt, S.J.; Schoch, R.R.; Hornung, J.J. (2011). Andrew A. Farke, ed. "The Sail-Backed Reptile Ctenosauriscus from the Latest Early Triassic of Germany and the Timing and Biogeography of the Early Archosaur Radiation". PLoS ONE. 6 (10): e25693. doi:10.1371/journal.pone.0025693. PMC 3194824. PMID 22022431.