Camposaurus is a small, carnivorous, theropod dinosaur. Its approximate length and weight cannot be reliably estimated because of the sparse material that is known from this genus. Camposaurus is known from partial lower leg bones, holotype UCMP 34498 (which includes distal tibiae, distal fibulae, and astragalocalcanea), and other fragmentary material. Like other coelophysids, it has fused tibio-tarsals and fibulo-tarsals. Unlike its relatives, the area of the tibia that fits with the fibula has a distinct ridge at the back. Another unique feature is the lack of a large medial condyle on the astragalus. The type species, C. arizonensis, was formally named and described by Adrian Hunt, Spencer G. Lucas, Andrew B. Heckert, Robert Sullivan and Martin Lockley in 1998. As the species name suggests, it was found in Arizona, in the United States.
The holotype specimen UCMP 34498 was discovered in the Placerias quarry of the Bluewater Creek Formation of Arizona, from the Norian stage of the Late Triassic period.