Notosuchia is a suborder of primarily Gondwanan mesoeucrocodylian crocodylomorphs that lived during the Jurassic and Cretaceous. Some phylogenies recover Sebecosuchia as a clade within Notosuchia, others as a sister group (see below); if Sebecosuchia is included within Notosuchia its existence is pushed into the Middle Miocene, about 11 million years ago. Fossils have been found from South America, Africa, Asia, and Europe. Notosuchia was a clade of terrestrial crocodilians that evolved a range of feeding behaviours, including herbivory (Chimaerasuchus), omnivory (Simosuchus), and terrestrial hypercarnivory (Baurusuchus). It included many members with highly derived traits unusual for crocodylomorphs, including mammal-like teeth, flexible bands of shield-like body armor similar to those of armadillos (Armadillosuchus), and possibly fleshy cheeks and pig-like snouts (Notosuchus). The suborder was first named in 1971 by Zulma Gasparini and has since undergone many phylogenetic revisions.[2]
Notosuchians were generally small, with slender bodies and erect limbs. The most distinctive characteristics are usually seen in the skull. Notosuchian skulls are generally short and deep. While most are relatively narrow, some are very broad. Simosuchus has a broadened skull and jaw that resembles a pug, while Anatosuchus has a broad, flat snout like that of a duck.
The teeth vary greatly between different genera. Many have heterodont dentitions that vary in shape across the jaw. Often, there are large canine-like teeth protruding from the front of the mouth and broader molar-like teeth in the back. Some genera, such as Yacarerani and Pakasuchus, have extremely mammal-like teeth. Their molars are complex and multicuspid, and are able to occlude or fit with one another. Some forms such as Malawisuchus had jaw joints that enabled them to move the jaw back and forth in a shearing motion rather than just up and down.
A derived group of notosuchians, the baurusuchids differ considerably from other forms. They are very large in comparison to other notosuchians and are exclusively carnivorous. Baurusuchids have deep skulls and prominent canine-like teeth.
The evolutionary interrelationships of Notosuchia are in flux, but the following genera are generally considered notosuchians: