July 3, 2012
Feathered Dinosaurs May Have Been The Norm
Brett Smith for redOrbit.com - Your Universe Online
One of the most complete dinosaur fossils ever discovered suggests that feathered dinosaurs were more prevalent than previously thought and could have been the norm, not the exception.
The 150 million-year-old fossil found in northern Bavaria shows that the dinosaur had down-like feathers over parts of its front and back as well on its tail. Scientists dubbed the creature Sciurumimus albersdoerferi after "Scirius”, the scientific name for tree squirrels.
"I was overwhelmed when I first saw it. Even apart from the preservation of feathers, this is certainly one of the most beautiful dinosaur fossils ever found," Oliver Rauhut, a paleontologist at the Bavarian State Collections of Palaeontology and Geology in Germany, told Christine Dell'Amore of National Geographic News.
“The specimen is preserved in complete articulation, lying on its right side,” he added.
Using ultraviolet light, scientists were able to illuminate the remains of the animal´s skin and feathers, which fluoresced around the fossilized skeleton. Their findings were published this week in the Proceedings of the National Academy of Sciences.
The fossil, with its disproportionately large size of the skull full of jagged teeth, indicates that this Sciurumimus was likely a very young megalosaur, a group of two-legged meat-eating dinosaurs.
Previously, paleontologists have only found feathers on small dinosaurs called coelursaurs. Some lineages of coelursaurs later evolved into modern-day birds, according to some theories.
Because megalosaurs existed before coelursaurs and are on a different branch of dinosaur evolution, this latest fossil discovery gives credence to the idea of a wide range of feathered dinosaurs.
"All of the feathered predatory dinosaurs known so far represent close relatives of birds," said Rauhut. "Sciurumimus is much more basal within the dinosaur family tree and thus indicates that all predatory dinosaurs had feathers.”
"We should say good bye to the familiar image of the overgrown lizards,” he suggested.
While those involved in the discovery and research of Sciurumimus appear ready to reboot the popular image of dinosaurs, some scientists remained skeptical about the idea of most dinosaurs having feathers.
"I would say that this is an obvious possibility, rather than an obvious conclusion," Corwin Sullivan, a paleontologist at the Chinese Academy of Sciences in Beijing told National Geographic.
"We paleontologists are going to need to find more fossils–of things even less closely related to birds than Sciurumimus–to be sure."
While the fossilized dinosaur was only about 28 inches in length, many adult megalosaurs reached about 20 feet in length and the researchers said this specimen would have likely grown to about that size.
These dinosaurs are thought to have been active predators, hunting both smaller prey and other large dinosaurs. Scientists said they believe that the animal they discovered probably hunted insects and other small prey, based on the slender, pointed teeth located in the tip of the jaws.
“This individual has a very different set of teeth from those found in adult megalosaurs,” said Rauhut. “That enables us to conclude that their diets also changed as they got older.”
The discovery of Sciurumimus marks over 150 years since the discovery of the most famous Bavarian fossil, that of Archaeopteryx. Found just two years after the publishing of Charles Darwin´s game-changing book On the Origin of Species, Archaeopteryx is widely considered to be the oldest known bird and its discovery initiated the theory that dinosaurs may have evolved into birds.