Meat-eating dinosaur from Argentina with a bird-like breathing system

Steve Koppes (USA) Mendoza, Argentina. The remains of a new ten-meter-long predatory dinosaur discovered along the banks of Argentina’s Rio Colorado are helping to unravel how birds evolved their unusual breathing system. In September 2008, palaeontologists, led by the University of Chicago’s Paul Sereno, a National Geographic Explorer-in-Residence, have published an article about their discovery in the online journal Public Library of Science ONE. Joining Sereno to announce the discovery at a news conference in Mendoza, Argentina, held on 29 September 2008, were Ricardo Martinez and Oscar Alcober, both of the Universidad Nacional de San Juan, Argentina. The discovery of this dinosaur builds on decades of paleontological research indicating that birds evolved from dinosaurs. Fig. 1. Flesh rendering of the predator Aerosteon with the body wall removed to show a reconstruction of the lungs (red) and air sacs (other colours) as they might have been in life. (Drawing: Todd Marshall c 2008, courtesy of Project Exploration) “Among land animals, birds have a unique way of breathing. The lungs actually don’t expand,” Sereno said. Instead, birds have developed a system of bellows, or air sacs, which help pump air through the lungs. This is the reason birds can fly higher and faster than bats, which, like all mammals, expand their lungs in a less efficient breathing process. Discovered by Sereno and his colleagues in 1996, the new dinosaur is named Aerosteon riocoloradensis (meaning “air bones from the Rio Colorado”). Sereno explained that “Aerosteon, found in rocks dating to the Cretaceous period … Read More