The Feathered Dinosaurs

 Paleontologists have found a couple clues leading them to infer some dinosaurs had feathers.  Some trace fossils have been found with imprints of feathers.  Some theropod fossils, like the velociraptor, have quill barbs or bumps on their arms. These barbs connect feathers to bones  Some theropod fossils, like the velociraptor, have quill barbs or bumps on their arms. These barbs connect feathers to bones. The Feathered Dinosaurs This archaeopteryx fossil clearly has feather imprints. This image of a velociraptor has feathers on its forearm where the barbs were found.

Liaoning Providence, China  Before the 1990s, the theory that dinosaurs had feathers was very much in debate.  Then, in the 1990s, a site in Liaoning Province, China was discovered containing a treasure of plant and animal fossils.  Some scientists think it is the best fossil site on earth for learning about the Mesozoic Era.  Paleontologists uncovered, and continue to discover, quite a few dinosaurs with evidence of feathers.  These fossils have turned the theory that dinosaurs had feathers from a debate to a widely held belief that birds are the direct descendants of feathered dinosaurs. China Liaoning Province

The Feathered Dinosaurs T-rex Compsognathus

 We know birds use feathers to fly. So, the logical conclusion would be that feathered theropods could fly.  But, feathers did not evolve so animals could fly. They first evolved to insulate warm-blooded animals. Flight is a secondary attribute of feathers.  So, dinosaurs originally evolved feathers to keep warm.  (This is also one of the arguments for the theory that theropods were warm-blooded.)  This theory is partly based on the type of feathers they had at first. The early feathered theropods were generally small with downy feathers. These downy feathers are not designed for flight. The Feathered Dinosaurs Why did theropods have feathers? This duckling is covered with down feathers, very similar to the kind of feathers the early theropods had. Red-tailed hawks have feathers that enable them to soar at great heights.

The Feathered Dinosaurs Feathers Designed for Flight

 Depending on which dinosaur fossil you are looking at, the answer to the above question changes.  But, besides feathers, there are a few things that some theropods and birds have in common.  Some examples are…  Wishbones.  Light and hollow bones.  Feet with three toes or claws  Bipedal walking The Feathered Dinosaurs Are feathers the only thing dinosaurs share with birds? These “Running Bird” skeletons and velociraptor skeleton both have light and hollow bones. These ornithomimids and ostrich both walk on two legs. This chicken foot and allosaurus foot look eerily similar with those claws coming out of their toes. Both birds and theropods have a wishbone.

The Feathered Dinosaurs

Falcarius (sickle maker) This theropod was discovered in Utah, North America and measures 13 feet (4 meters) long and weighed 500 pounds. Most theropods are carnivores, but due to its teeth and large intestines, scientists believe it might have been an omnivore or even an herbivore. Paleontologists also believe it was one of the transitional theropods, evolving from the earlier more typical looking theropod, like the velociraptor, to the newer and strange looking theropods known as the therizinosaurs.

The Sinosauropteryx (Chinese lizard wing) was a smaller dinosaur measuring 4 feet (1.2 meters) long and weighed between 10 and 20 pounds. It is one of the more famous dinosaurs found in Liaoning, China because 3 complete fossils, eggs, some organs, and even what was in its stomach have been recovered. Not only that, but the trace fossils showing solid evidence of primitive feathers were the first fossil imprints ever definitively proving that dinosaurs had feathers. Most models and statues made of dinosaurs are probably not accurate because usually we don’t know what color they were. But, according to scientific research, the orange and white stripes on the Sinosauropteryx’ tail are accurate.

Mei The Mei’s unique name, meaning “sound asleep”, is due to the fact its fossil was discovered curled up in a sleeping position. Scientists think it was one of the theropods with a direct link to modern birds. It was a couple feet (.6 meters) long and weighed about 2 pounds and lived during the early Cretaceous Period.

Caudipteryx The Caudipteryx (tail feather) lived in Asia spending most of its time near water. It weighed 20 pounds and was 3 feet (1 meter) long. It was the third feathered theropod found in the Liaoning Providence, furthering the link between dinosaurs and birds. Even though it has many bird like characteristics, (avian beak, feet, and feathers) scientists believe it couldn’t fly, still classifying it as a dinosaur.

Chirostenotes Chirostenotes (narrow hand) lived 80 million years ago, during the Cretaceous Period. It weighed about 50 pounds and was 7 feet (2.1 meters) in length. This theropod was closely related to the Oviraptor and was probably an omnivore. An interesting fact about Chirostenotes is, over time, it has had three name. This is because its fossils were found in pieces over many years and every piece was believed to be from a different dinosaur.

Sinornithosaurus The Sinornithosaurus (Chinese bird-lizard) is another dinosaur found in the Liaoning Providence of China. It might even be the most famous because its body was perfectly preserved. Scientists have discovered that it had different types of feathers on different parts of its body. Even though it is technically a raptor, it is more closely related to another famous “dino- bird”, the Archaeopteryx. It was three feet (1 meter) long and weighed between 5 and 10 pounds.

Nomingia The Nomingia is named after the area of Mongolia where its fossil was first found. It lived 65 – 70 million years ago in the late Cretaceous Period. It weighed 25 pounds and measured 6 feet (1.8 meters) in length. This dinosaur had a characteristic that all birds have today, a tail with a fan of feathers. Though its tail wasn’t quite like the peacock’s, it probably had the same purpose, to find a mate.

Microraptor The Microraptor (small thief) was a tiny theropod weighing only 3-4 pounds and measuring 2 feet (.6 meters). Its claim to fame are its two pairs of wings, one pair on its arms and one pair on its legs. Even though it technically had four wings it probably couldn’t fly. It spent most of its time in the trees and was able to glide from the tree tops with its numerous wings. In fact, it was probably able to dive down and skim the top of bodies of water and catch fish.

Protarchaeopteryx The Protarchaeopteryx lived about million years ago, during the early Cretaceous Period. This tiny dinosaur was only two feet (.6 meters) long and weighed three pounds. Its name means before archaeopteryx, even though it lived after its more famous namesake. This feathered dinosaur roamed the woodlands of Asia and, though it had wings, was unable to fly.

Archaeopteryx The Archaeopteryx (ancient wing) is one of the most important fossils ever discovered. It is generally thought of as being the first bird but, even though it has many bird features, it also had many reptilian features. For example, its feathers, wings, and wishbone, are all characteristics of modern birds. But, its full set of teeth, bony tail, and claws are not found in any of today’s birds. What we do know is it is definitely a link between dinosaurs and birds.