Dinosaurs With Feathers Thought to Be the Norm

 

dinosaursA new species of feathered dinosaur was discovered in Russia, indicating that the trait may have been the norm rather than the exception.  This newly found dinosaur was about five feet long and belonged to a group known as ornithischia. They were beaked herbivores.

Feathered dinosaurs were first found in China in 1996. But those specimens were all theropods. Tyrannosaurus rex  is the most well-known member of this group. This, however, is the first time that a feathered dinosaur has been found outside of the theropod lineage.

This new ornithischian dinosaur, called Kulindadromeus, lived near Siberia’s Kulinda River. It had feathery tufts on both its legs and elbows. It also had streamlined feathers on its back. While earlier discoveries of ornithischians in China had bristles that were feather-like, the Kulindadromeus discovery came complete with fossilized feather imprints.

The find, which included six skulls and many bones expands the number of families that had feathers. Plumes that covered earlier reptiles probably served as insulation. The fossiled imprints of Kulindadromeus are different than the ones found on other feathered dinosaurs and modern-day birds.

Theropods and ornithischians split about 220 million years ago. Finding feathered dinosaurs in both lineages suggests that the trait of having feathers was  much more widespread in the dinosaur lineage. A major problem, however, is that feathers are rarely fossilized. It is also clear that while these creatures had feathers, they did not fly. Feathers themselves are also subject to the evolutionary process.

Describing this newly found dinosaur is the job of Pascal Godefroit, the lead author of the study. Previously, ornithischians were found with simple bristles or quills. However, scientists were unable to positively identify whether they were feathers.

Until the find in Russia, feathers and dinosaurs were thought to be exclusively the province of theropods. Dinosaurs were initially grouped into two basic divisions, saurischia and ornithischians.  Theropods and sauropodomorphs both fall within the saurischia family.

Theropods include the largest two-legged carnivores to roam the earth. Birds are direct descendents of smaller, non-flying dinosaurs in this group. General characteristics of theropods include hollow bones, smaller hands, large feet with three weight bearing toes, sharp, curved teeth and claws at the end of each finger and toe.

Sauropodomorphs were mostly four-legged giant herbivores with long necks. They became the largest creatures ever to roam the earth. Their characteristics included a small, tiny head, a long tail to counteract the long neck, and weak, spoon-shaped teeth.

Ornithischians basically include everything that remains, including ceratopsians and hadrosaurs.  They were herbivores and several had body armor, horns and spikes for protection like the stegosaurs, close relatives of the ankylosaurs. Their common thread was a pubis that pointed backwards. Birds also have a pubis that points backwards, but are not linked to this group, but rather evolved from the saurischia group.

There is significant evidence to support that birds evolved from the theropod dinosaurs. The Russian discovery, however, is the first evidence that the ornithischia with their backward pubis could also have been feather-like. It all goes to show that re-creating the evolutionary process is a continually changing endeavor.

Dinosaurs have captivated the imagination of people for millennia. Countless questions continue to be raised whenever new discoveries are made. Dinosaur stories and movies continue to fan a curiosity that seems it will never be satisfied. With each new discovery new debates of their evolutionary journey arise.

The find suggests that the ancestors of theropod and ornithischia dinosaurs had feathers. This greatly expands the number of feather-like dinosaurs and suggests that may have been the norm of the earliest dinosaurs.

By Hans Benes

Sources:

New York Times
CBC News
National Geographic
UCMP

4 Responses to "Dinosaurs With Feathers Thought to Be the Norm"

  1. Hans Benes   July 29, 2014 at 10:17 pm

    Dinosaur Ridge in Morrison, CO is only about 1/2 hour away. I should go and revisit to see some real fossils. I should also schedule a trip to the Dinosaur National Monument.

    Reply
  2. Michael Schultheiss   July 29, 2014 at 9:51 pm

    Right on! They are fascinating, aren’t they? I became obsessed with them at a very young age and wished to become a paleontologist. They still fascinate me.

    Reply
  3. Hans Benes   July 29, 2014 at 9:46 pm

    Thank you, Michael. I’m looking at dinosaurs in a whole new light while learning a new language, or so it seems. 🙂

    Reply
  4. Michael Schultheiss   July 29, 2014 at 8:53 pm

    Hans, you did a good job with this article. Keep it up! I wonder what group of dinosaurs will next be found to have had feathers?

    Reply

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