This is Bill White with the VOA Special English SCIENCE REPORT.
For the first time, American scientists say they have discovered the heart of a dinosaur. The heart was discovered in the remains of a dinosaur recovered seven years ago in the state of South Dakota.
The scientists say computer images suggest the heart is similar to the hearts of birds and mammals. The findings add to evidence that at least some dinosaurs were not slow, but were quick and active.
Scientists say the dinosaur belonged to a group of plant-eating creatures known as Thescelosaurus. It was about four-meters long and weighed about three-hundred kilograms. It died about sixty-six million years ago, shortly before all dinosaurs on earth suddenly disappeared.
The scientists named the dinosaur Willo, after the wife of the man who owned the land in South Dakota where the remains were found. The remains were later moved to North Carolina where they can be seen today.
Scientists from North Carolina State University examined Willo's chest area by using computerized imaging technology. Their findings are reported in the publication Science.
The scientists say the images showed the remains of a fossilized heart. Team member Dale Russell says the heart appears similar to the hearts of animals like birds or mammals that are warm-blooded and very active. Many scientists consider dinosaurs more closely related to cold-blooded, slow animals like reptiles.
The scientists say Willo's heart appears to have four chambers, or parts. This is similar to the heart structure of birds and mammals. They say a single main artery carried blood from the heart to the rest of the body. Reptiles have only three heart chambers. They have two main arteries to carry blood to the body.
Earlier studies have shown similarities between birds and dinosaurs. Many scientists believe some kinds of dinosaurs were the ancestors of modern birds. .
Some scientists praised the heart discovery. But others questioned the findings. Those researchers note that the upper chambers of Willo's heart and some major blood vessels cannot be seen.
The North Carolina scientists say these areas may have broken down completely. They say they plan to produce more detailed images of the dinosaur's heart.
This VOA Special English SCIENCE REPORT was written by George Grow. This is __________.