| Named By: | Broili in 1904 |
| Time Period: | Late Carboniferous - Early Permian |
| Location: | USA, New Mexico & Texas |
| Size: | Unavailable |
| Diet: | Carnivore |
| Fossil(s): | Several individuals, though usually very incomplete |
| Classification: | | Chordata | Amphibia | Temnospondyli | Dissorophidae | Cacopinae | |
| Also known as: | | Broiliellus novomexicanus | Zatrachys apicalis | Zatrachys crucifer | |
Aspidosaurus is an extinct genus of dissorophoid temnospondyl within the family Dissorophidae. Like other dissorophids, Aspidosaurus species had a single row of plates formed by expansions of the neural spines.
In 1911, Paul Miller discovered the remains of various dissorophid bones in New Mexico that were attributed to a new species, Aspidosaurus novomexicanus. The skull closely resembled that of a specimen of Cacops aspidephorus found in Texas but the arrangement of ridges in the otic region was different. The teeth found were slender and conical and all of an approximately equal size. The vertebral column, pelvis and limb bones were also similar but the new specimen was distinguished from Cacops by the armour, the single row of vertical plates that were originally attached to the neural spines of the vertebrae. A. novomexicanus was later attributed to the genus Broiliellus. More recently, "A." novomexicanus has been removed from Broiliellus and classified as a closer relative of Cacops. The original specimen is now housed in the University of California Museum of Paleontology and is referred to as the "Rio Arriba taxon" because of its uncertain phylogenetic placement.