Aerosteon, scientifically named "Aerosteon riocoloradensis," is a member of the Megaraptora group, a branch of theropod dinosaurs. Its name derives from the Greek words "aero" (air) and "osteon" (bone), alluding to its remarkable air-filled bones. This dinosaur lived during the Late Cretaceous period, approximately 90 million years ago.

The discovery of Aerosteon was made in the Anacleto Formation of Patagonia, Argentina, in 1996. Its unique skeletal features have sparked considerable interest among scientists, providing valuable insights into the adaptations of ancient dinosaurs.

Aerosteon was a sizeable theropod dinosaur, measuring around 33 feet (10 meters) in length. Its most distinguishing feature lies in its air-filled bones, known as pneumaticity, which is a rare trait among theropods. Pneumaticity is a condition where air sacs from the respiratory system invade the skeletal bones, making them lightweight and contributing to the dinosaur's overall agility and movement. Initially, these air sacs appeared as features on the sides of vertebrae before becoming integrated within various bones throughout the skeleton. These air sacs likely functioned as bellows, facilitating the movement of air into and out of the animal's relatively rigid lungs, as opposed to the lungs themselves expanding and contracting, as observed in mammals.

In addition to its air-filled bones, Aerosteon had sharp, serrated teeth, typical of theropods, which it used to subdue and tear apart its prey. Its long tail and slender limbs suggest it was a swift and agile predator.