1. Headline
  1. Headline
Image: Track marks
Steve Salisbury
Track marks thought to have come from stampeding dinosaurs may actually come from swimming dinosaurs at a major river crossing, new research suggests.
By
updated 1/18/2013 1:14:09 PM ET 2013-01-18T18:14:09

Fossilized track marks from a stampede of dinosaurs in Australia actually may have come from swimming animals, new research suggests.

The finding, published in the January issue of the Journal of Vertebrate Paleontology, upends the traditional interpretation of the world's only dinosaur stampede.

Instead of a group of small dinosaurs trying to escape a massive carnivore, the fossils may reveal an ancient dinosaur "superhighway" or river crossing, said study co-author Anthony Romilio, a paleontologist at the University of Queensland in Australia.

Dinosaur tracks
Some 3,000 to 4,000 fossilized dinosaur footprints were formed about 95 million years ago in a sandy riverbank in what was once a lush, coniferous forest. The site, known as Lark Quarry, is only about the size of a basketball court, and has become an enclosed and air-conditioned museum — a major tourist attraction in Australia.

The tracks came from several types of dinosaurs, ranging in size from a chicken to an emu with one oddball: a giant dinosaur that left its 23.6-inch-long (60 centimeters) footprints there.

In 1984, scientists Tony Thulborn and Mary Wade interpreted the tracks as evidence of a stampede of smaller dinosaurs escaping the clutches of a 4-ton theropod, a bipedal carnivore. [ Paleo Art: Stunning Illustrations of Dinosaurs ]

But in recent work, Romilio and his colleagues studied the large track marks and concluded the primeval creature was actually a large plant-eating dinosaur called Muttaburrasaurus. That suggested the "fleeing a predator" theory needed a rethink.

Superhighway swimmers
Rather than just analyzing two-dimensional outlines of the tracks, Romilio used three-dimensional computer modeling. [ See 3D animation of tracks ]

  1. Science news from NBCNews.com
    1. Cosmic rays may spark Earth's lightning
      NOAA

      All lightning on Earth may have its roots in space, new research suggests.

    2. How our brains can track a 100 mph pitch
    3. Moth found to have ultrasonic hearing
    4. Quantum network could secure Internet

Tracks originally thought to come from a long-toed dinosaur showed deep indentations, as if a short-toed dinosaur had dug its toes into the muddy river bottom.

"The animals were going on tippy-toes, kind of like a prima ballerina would dance across the stage," Romilio told LiveScience.

The site also has traces of dragged vegetation, consistent with a fast-flowing river, he said.

Based on their tracks, the swimming animals were moving downstream with the current. The tracks from similar dinosaurs also revealed that the water level changed dramatically, from as much as 15.7 inches to 6 inches (40 cm to 15 cm) high, he said.

  1. More from TODAY.com
    1. Bath time! Watch this pit bull lick baby into a fit of laughter

      It seems that bath time for your toddler doesn't have to be such a struggle. That is, if your pet dog is willing to pitch in.

    2. Five cases when buyer's remorse will cost you big
    3. Better off red: Julianne Moore, daughter join fiery stars in Vogue gallery
    4. 5 things we love about H&M's fall home collection
    5. Two abandoned baby hedgehogs get some TLC after a prickly start

The findings suggest that large groups of dinosaurs used this route over several days while migrating, he said.

"It must have been quite the highway for these very small dinosaurs," Romilio said.

Still a stampede
A scientist not involved in the study said the new findings are convincing but don't change the view that the fossils are from a stampede.  It just happened to occur in water, said Paul Willis, a vertebrate paleontologist from the Royal Institution of Australia. It may have been a massive stampede like those of wildebeests in the Serengeti, Willis said.

"There are certainly some footprints there that I've seen that are consistent with a small dinosaur that is swimming and it can't quite touch the bottom with its toes, but it still looks like we are talking about a significant group of dinosaurs all moving together as one mob."

Follow LiveScience on Twitter@livescience. We're also onFacebook &Google+.

© 2012 LiveScience.com. All rights reserved.

Discuss:

Discussion comments

,

Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments

More on TODAY.com

  1. Ann and Steve Toon/Solent News

    Two abandoned baby hedgehogs get some TLC after a prickly start

    7/30/2014 6:42:41 PM +00:00 2014-07-30T18:42:41
  1. Michael Dwyer / AP

    Five cases when buyer's remorse will cost you big

    7/30/2014 9:03:12 PM +00:00 2014-07-30T21:03:12
  1. Courtesy Graves family

    Death-defying: Mom battled cancer while ‘feisty’ baby waited for a new heart

    7/30/2014 2:52:11 PM +00:00 2014-07-30T14:52:11
  1. Strike on Gaza shopping area kills at least a dozen, wounds 150

    An Israeli airstrike hit a crowded Gaza shopping area on Wednesday, killing at least 16 people and wounding more than 150, just hours after Israeli tank shells slammed into a U.N. school, Gaza health officials said.

    7/30/2014 5:38:37 PM +00:00 2014-07-30T17:38:37
  1. Twitter.com/SarahDrewGreys

    'Grey's Anatomy' star Sarah Drew reveals her baby bump

    7/30/2014 5:07:52 PM +00:00 2014-07-30T17:07:52
  1. Courtesy of CSPI

    The 'fattest' chain restaurant meals win a dubious honor

    7/30/2014 2:50:15 PM +00:00 2014-07-30T14:50:15