Navigation Links
New meat-eating dinosaur from Argentina had bird-like breathing system
Date:9/29/2008

MENDOZA, ArgentinaThe remains of a new 10-meter-long predatory dinosaur discovered along the banks of Argentina's Rio Colorado is helping to unravel how birds evolved their unusual breathing system.

Paleontologists led by the University of Chicago's Paul Sereno, a National Geographic Explorer-in-Residence, will publish their discovery Sept. 29 in the online journal Public Library of Science ONE. Joining Sereno to announce the discovery at a news conference in Mendoza, Argentina, today 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.

"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. It's 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 ("air bones from the Rio Colorado"). "Aerosteon, found in rocks dating to the Cretaceous period about 85 million years old, represents a lineage surviving in isolation in South America. Its closest cousin in North American, Allosaurus, had gone extinct millions of years earlier and was replaced by tyrannosaurs."

Laboratory technicians spent years cleaning and CT-scanning the bones, which were embedded in hard rock, to finally reveal the evidence of air sacs within Aerosteon's body cavity. Previously, paleontologists had found only tantalizing evidence in the backbone, outside the cavity with the lungs. "This dinosaur, unlike any other, provides more direct evidence of the bellows involved in bird breathing," Martinez said. Its bones have telltale pockets and a sponge-like texture called "pneumatization," in which air sacs from the lung invade bone. Air-filled bones are the hallmark of the bellows system of breathing in birds.

Alcober noted, "Despite its huge body size and lack of a breastbone or birdlike ribcage, this meat-eater had lungs that already functioned quite a bit like a bird's."

Aerosteon provided the evidence needed to seal the connection with birds hollow bones in front and behind the ribcage, such as the wishbone (furcula) and the main hip bone (ilium).

Said co-author of the PLoS ONE article Jeffrey Wilson of the University of Michigan, "The ancient history of features like air sacs is full of surprising turns, the explanations for which must account for their presence in a huge predator like Aerosteon as well as in a chicken."

Sereno further noted that Aerosteon has air sacs in an unusual place. "They come around the edge of the body and go into belly ribs. It looks like the beast had a system of air tubes under its skin," he said.

The team highlighted three explanations for the evolution of air sacs in dinosaurs in their paper: development of a more efficient lung; reduction of upper body mass in tipsy two-legged runners; and release of excess body heat.

Sereno is especially intrigued by heat loss, given that Aerosteon was likely a high-energy predator with feathers but without sweat glands as in birds. At approximately 30 feet in length and weighing as much as an elephant, Aerosteon might well have used an air system under the skin to rid itself of unwanted heat.


'/>"/>

Contact: Steve Koppes
skoppes@uchicago.edu
773-702-8366
University of Chicago
Source:Eurekalert  

Related biology news :

1. Meat-eating dinosaur from Argentina had bird-like breathing system
2. Americas smallest dinosaur uncovered
3. Dinosaur diggers bring mobile lab, new techniques to Eastern Montana
4. Did the solar system bounce finish the dinosaurs?
5. Genetic sequencing of protein from T. rex bone confirms dinosaurs link to birds
6. Medical College researchers find dinosaur clues in fat
7. Grand Canyon may be as old as dinosaurs, says new study
8. Quantum weirdness, parallel worlds, dinosaur poop, and the ultimate fate of the universe...
9. New dinosaur from Mexico offers insights into ancient life on West America
10. Seismic images show dinosaur-killing meteor made bigger splash
11. Unusual fish-eating dinosaur had crocodile-like skull
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
New meat-eating dinosaur from Argentina had bird-like breathing system
(Date:12/15/2016)... VANCOUVER, Canada and BADEN-BADEN, Germany ... Solutions, a leading global financial services provider, today announced an ... in passive behavioural biometrics, to join forces. The partnership will ... fraud mitigation strategies in compliance with local data protection regulation. ... In ...
(Date:12/15/2016)...  There is much more to innovative access systems ... Continental will demonstrate the intelligence of today,s solutions at ... Through the combination of the keyless entry and start ... the international technology company is opening up new possibilities ... "The integration of biometric elements brings our expertise ...
(Date:12/8/2016)... , Dec. 8, 2016  Singulex, Inc., the ... Counting technology, entered into a license and supply agreement ... science. The agreement provides Singulex access to Thermo Scientific ... Europe is used to diagnose systemic bacterial ... States to aid in assessing the risk ...
Breaking Biology News(10 mins):
(Date:1/24/2017)... (PRWEB) , ... January 24, 2017 , ... ... waist circumference, and increased serum leptin levels had a positive association with increased ... The study published in the International Neurourology Journal involved 571 Korean men ...
(Date:1/24/2017)... ... January 23, 2017 , ... ... science through unique partnerships, seeks outstanding early career nominees for the 2017 New ... to meeting the needs of a world in which one in nine people ...
(Date:1/24/2017)... , Jan. 23, 2017   Instrument Business Outlook ... Minneapolis, MN ) the 2016 Company ... most authoritative newsletter tracking developments in the analytical ... "Bio-Techne consistently achieved outstanding technical, operational and ... Managing Editor of IBO. "In 2016, Bio-Techne capitalized ...
(Date:1/23/2017)... , Jan. 23, 2017   Enteris BioPharma, ... study agreement with Sanofi to leverage Enteris, ... platform, Peptelligenceā„¢, to develop an oral formulation of one ... Joel Tune , Chief Executive Officer and Executive Chairman ... further validation of the tremendous value our Peptelligence platform ...
Breaking Biology Technology: