Feathery find: scientists discover that some dinosaurs sported feathers.
Recently, fossil hunters discovered a 2-meter (6.5-foot)long feathered tyrannosaur--in the same family as the towering, toothy T. rex--in Liaoning. After studying this ancient fossil, Mark Norell and Xu Xing, paleontologists at the American Museum of Natural History in New York, found that the ostrich-size dinosaur sported birdlike feathers from head to tail.
What's the big deal? This was the first evidence that tyrannosaurs, relatives of today's birds, had feathers. With this fossil and other remains from Liaoning, scientists can confidently claim that many dinosaurs were covered with birdlike feathers.
Liaoning produced other surprises too. Armed with shovels and picks, fossil hunters have found thousands of plant and animal remains. Using these fossils, paleontologists have pieced together an entire ancient forest community. SuperScience spoke with Norell to learn more.
What makes Liaoning Province special?
It is our most complete picture of a prehistoric forest from the Cretaceous (kreh-TAY-shus) period, when dinosaurs lived. That's because we have found so many plant and small animal fossils--things such as crayfish, mothlike creatures, and fish. When you find fossils, they are usually the remains of large animals. But in Liaoning, you find fossils of these smaller animals too. It's rare to find so many different types of fossils preserved from the same time.
When you studied these fossils, did anything surprise you?
If you think about when ancient dinosaurs lived, most people imagine a swamp full of gigantic, scaly animals. Liaoning shows that this wasn't the case. The ancient forest looked like a modern forest with familiar things--like dragonflies and pine trees. But it also held surprises: A lot of dinosaurs would have looked really strange because they were completely feathered--like the recently discovered tyrannosaur.
How are fossils created?
Different fossils form in different ways. In one type, called replacement fossils, the original bone and other material has been replaced by minerals, such as silica or calcite. There are also imprint fossils, like footprints or molds of bones in rock.
Why does Liaoning hold so many great fossils?
Ancient animals and plants living there were buried in volcanic ash, a very fine-grained sediment. Probably there were volcanoes erupting nearby, and ash was constantly raining down for tens of millions of years.
What's it like on a typical dig?
Sometimes, it involves camping for months on end. When we're in the desert and hundreds of miles away from any town, we have only enough water to drink and wash off. On these digs, we don't get to bathe all summer. But, in some places, we get to stay in hotels and eat in restaurants.
Do you have any advice for kids who want to become paleontologists?
More people want to dig than get to do it, so the best thing you can do is study hard and get a good education.
Words to Know
Fossil--the remains of a plant or animal that lived long ago
Sediment--particles such as ash, dirt, or dust
Tyrannosaur--large, meat-eating two-footed dinosaur
Paleontologist--scientist who studies life in the past, especially through plant and animal fossils
check it out!
Artists and scientists at the American Museum of Natural History in New York City have created a life-size diorama of Liaoning's prehistoric forest for the exhibition Dinosaurs: Ancient Fossils, New Discoveries. With more than 30 million objects in its collection, the Museum has been researching and celebrating the natural world for more than 135 years. Its 200 scientists travel around the world on 100 field expeditions each year, studying everything from dinosaurs to ocean life to the universe.
SCIENCE CONTENT STANDARDS
For Grades K-4
* Changes in earth and sky
* Characteristics of organisms
For Grades 5-8
* Earth's history
* Diversity of organisms
INTEGRATE YOUR CURRICULUM!
Language Arts--Reading comprehension
Set a Purpose
To Learn about fossils discovered in China.
* The Cretaceous period lasted from 140 million years ago to 65 million years ago. This period marked the heyday of dinosaurs and was characterized by the development of flowering plants.
* Tyrannosaurs were large meat-eating dinosaurs that grew to lengths of 47 feet (14.3 meters) or more.
* Tyrannosaurs belong to a broader, diverse group of dinosaurs known as the coelurosaurs. Most paleontologists believe this group gave rise to birds.
* What are some things you know about dinosaurs? (Possible answers: They lived millions of years ago; some ate meat, others ate plants; some were large.)
* We learn about dinosaurs from the information given to us by scientists. How do scientists get this information? (Possible answers: They study dinosaur fossils; they read books.)
* Why is Liaoning Province such a great place to search for fossils? (Possible answer: Many dinosaurs were buried there.)
Dinosaurs: Ancient Fossils, New Discoveries will be on exhibit at the American Museum of Natural History in New York City from May 14, 2005, until January 8, 2006. After that it will travel around the country. To find a location near you, go to the Web site above.
From the Dinosaurs of the Post to the Birds of the Present by Marianne Johnston (PowerKids Press, 2000) has graphs, photos, and drawings that show the link between dinosaurs and birds.
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|Title Annotation:||earth science|
|Date:||May 1, 2005|
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