155Myr Fossil could be Avian or Avian fore-runner

Posted: May 29, 2013 by tallbloke in paleo

Sciencenews brings us this fab fossil found in China’s Tiaojishan formation:

A birdlike fossil that dates to roughly 155 million years ago is ruffling the feathers of some paleontologists. At issue is whether the fossil is a dinosaur, an early bird or something in between.

“This new animal is the most primitive bird in the world,” says paleontologist Pascal Godefroit of the Royal Belgian Institute of Natural Sciences. He and an international team of colleagues describe the new specimen May 29 in Nature. The fossil comes from northeastern China’s Tiaojishan formation and is named Aurornis xui.

Not everyone agrees with Godefroit’s interpretation. “This is very birdlike, but it is not yet a bird,” says paleontologist Luis Chiappe of the Natural History Museum of Los Angeles County.

Read the rest here

  1. grumpydenier says:

    I refer you to my earlier Tweet.

  2. tallbloke says:

    Did you catch my reply? 🙂

  3. grumpydenier says:

    Yep, I haven’t quite sussed out how Twitter works yet.

    I noticed JD ignored it lol.

  4. tallbloke says:

    He may be having a life this evening 😉

  5. Doug Proctor says:

    Iron staining has been found elsewhere to show positions of internal organs. Intestinal? at top of tail, heart/lungs? by right arm, gizard? behind neck vertebrae?

    Bird, dinosaur: pick your definitions, does it have to fly?

    Kiwis, moas, penguins, farm chickens, farm turkeys. Define something too much and even your birds become not-birds, mostly.

  6. Scute says:

    I would plump for something that lived like a flying squirrel because the tail is long and slender. This thing needed it for something and I reckon it might have been for balance. If you add some lightweight scales (or proto feathers) to that tail it could work nicely as a balancing device but also as an aileron in short glides. The intermediate function might have been flicking it so as to achieve balance via aerodynamics as opposed to counter weighting as it would be more efficient. I think this is why squirrels have fluffy tails and flick them vigorously when running along branches.

  7. Re: Doug Proctor (May 29 23:39),

    Bird, dinosaur: pick your definitions, does it have to fly?

    Does it taste like chicken? 😉

  8. Zeke says:

    I would not try to eyeball it. Bird skeletal systems are unique in many ways.

    “The hollow inside of a bird’s ulna – a bone from the arm – is depicted in the photograph at left. In some species of birds, the air-filled skeleton is so lightweight that the bird’s feathers weigh more than its entire skeleton!

    The bones of a bird’s pelvic girdle and the lumbar, sacral, and a few caudal vertebrae are fused into a single, solid structure called the synsacrum.

    Avian ribs are broad, flat, and lie close enough together to prevent much compression. In addition, each rib overlaps the next due to an uncinate process.”

    Beautiful photographs here: http://www.hsu.edu/pictures.aspx?id=1287

  9. oldbrew says:

    “This is very birdlike, but it is not yet a bird,” says paleontologist

    Having four legs gives the game away 😉