Aucasaurus was a medium-sized carnivorous theropod from the family known as the abelisaurids and lived in Argentina, South America during the Late Cretaceous.
DiscoveryAucasaurus is not a very well-known dinosaur. However, it's quite famous in the paleontology universe because the skeleton that we know this theropod from is the most complete of any abelisaurid. It was first discovered in the badlands of Argentina in 1999 but wasn't officially named until three paleontologists named Coria, Chiappe, and Dingus came up with the name Aucasaurus, meaning "Auca lizard", after the place it was first found in. Currently we have only one specimen of this rare theropod but the fact that it's nearly intact helps us piece together a lot about it. One interesting feature about the specimen found in Patagonia was its skull. It seemed to have been damaged shortly before it died. It's not quite known what may have been the cause of this but most scientists agree that it was likely caused by two Aucasaurus that were fighting and this specific specimen was bitten on the face and likely died shortly after.
DescriptionAucasaurus is an abelisaurid closely related to Carnotaurus and Majungasaurus. It grew to be about 4.3 metres (14.1 ft) long and is said to weigh 1,500 lbs. This makes it quite small compared to other abelisaurids and theropods, since its close relative Carnotaurus grew to be about 30 feet (9 meters) long and nearly 3 tons in weight. It is depicted as a pack hunter, hunting dinosaurs like Saltasaurus. The name Aucasaurus comes from the words: "Auca" after the site of its discovery, Auca Mahuevo, and "Sauros" which means lizard. It likely fed on small to medium-sized sauropods like Saltasaurus, and was a second predator after the carnosaurs like Giganotosaurus, Mapusaurus, and Tyrannotitan. It had long, sturdy legs and very short arms that were deemed close to useless. They were so small in fact that it's debated whether or not it even had fingers at all! Its skull was somewhat short, but was boxy and thick, suggesting it had powerful jaws. It's teeth were also very thick and durable, like most abelisaurids, and were perfectly designed for ripping off chunks of flesh from carcasses.
In the MediaAucasaurus was in the documentary Dinosaur Planet, and the main one was a sub-adult named Dragonfly, who constantly harrassed and was eventually killed by a young Saltasaurus named Alpha.