| Named By: | Tom Rich and Patricia VickersinRich in 1989 |
| Time Period: | Early Cretaceous,[1]114 Ma |
| Location: | Australia - Victoria - Eumeralla Formation |
| Size: | Estimated between 2 and 3 meters long |
| Diet: | Herbivore |
| Fossil(s): | Partial maxilla (upper jaw) and teeth |
| Classification: | | Chordata | Reptilia | Dinosauria | Ornithischia | Ornithopoda | Hypsilophodontidae | |
Atlascopcosaurus (meaning "Atlas Copco lizard") is a genus of herbivorous basal euornithopod dinosaur from the Early Cretaceous of the present Australia.
The type specimen, NMV P166409, was found in 1984 at the Dinosaur Cove East site at the coast of Victoria, in layers of the Eumeralla Formation dating from the early Cretaceous, Aptian-Albian. This holotype consists of a piece of the upper jaw, a partial maxilla with teeth. Nothing else is known about it; as the rest of the skeleton remains undiscovered it can only be inferred from closely related species that the genus represents a small bipedal herbivore. By extrapolation it has been estimated that it was about two to three metres (6.5-10 ft) long and weighed approximately 125 kg. Because the teeth are not species-specific and the maxilla fragment is little informative, the taxon is today commonly seen as a nomen dubium.
The type species, Atlascopcosaurus loadsi, was named and described by Tom Rich and Patricia Vickers-Rich in 1988/1989. The generic name refers to the Atlas Copco Company who had provided equipment for the dig that discovered this dinosaur in 1984. The project revealed 85 fossil bone fragments of various species. This opened the door for more excavation and, along with other companies, Atlas Copco helped over ten years excavate about sixty metres of tunnel in a cliff wall at the sea shore. The specific name, loadsi, honours William Loads, the state manager for Atlas Copco at the time, who assisted during the dig.
Atlascopcosaurus was in 1988 assigned to the Hypsilophodontidae. These are today seen as an unnatural (paraphyletic) group and Atlascopcosaurus is now simply considered a basal member of the Ornithopoda.