Notosuchus was relatively small, reaching 1.5 m (4.9 ft) in length and a weight of 36 kg (79 lb).^[2] Remains have been found in the Bajo de la Carpa Formation in Patagonia, Argentina. First named in 1896, Notosuchus was the first known notosuchian.^[3] The type species is N. terrestris. A second species, N. lepidus, was named in 1957.^[4]

A paper published in 2008 by Fiorelli and Calvo described new remains of the type species N. terrestris.^[5] In it, the authors suggested that the skull would have supported a short trunk, or "hog's snout" as well as fleshy upper and lower lips. The anteriorly directed nares and the absence of a bony nasal septum (which presumably indicates cartilaginous tissue serving its place) provide evidence for a trunk-like snout, while striations on the surface of the nasal bones and the lower jaw most likely acted as attachment points for the nasolabial muscles and the depressor muscle, respectively.^[6] Additionally, the authors suggested that a lateral rim on the dentary as well as numerous aligned neurovascular foramina are evidence of soft cheek-like muscular tissue. The function of the trunk was likely used for searching for food by sniffing the ground in a manner similar to extant suids and peccaries, while the cheeks would aid in mastication by preventing food loss.^[5] A re-description of the skull material has since lent evidence toward minimal soft-tissue enhancement to the snout of Notosuchus.^[7]