Dinosaurs 'may have been warm-blooded'

2012-06-28 10:07

Paris - Dinosaurs may have been warm-blooded, scientists said on Wednesday, in a finding that could debunk one of the most commonly-held images of the extinct giants.

Researchers in Spain and Norway reported in the journal Nature that they had found tree-like growth rings on the bones of mammals, a feature that until now was thought to be limited to cold-blooded creatures ... and dinosaurs.

They also found evidence that dinosaurs probably had a high metabolic rate to allow fast growth - another indicator of warm-bloodedness.

"Our results strongly suggest that dinosaurs were warm-blooded," said lead author Meike Koehler of Spain's Institut Catala de Paleontologia.

If so, the findings should prompt a rethink about reptiles, she said.

Modern-day reptiles are cold-blooded, meaning they cannot control their body temperatures through their own metabolic system - relying instead on external means such as basking in the sun.

While the dinosaurs may have been warm-blooded, their other characteristics kept them squarely in the reptile camp, said Koehler.

Palaeontologists have long noted the ring-like markings on the bones of cold-blooded creatures and dinosaurs, and taken them to indicate pauses in growth, perhaps due to cold periods or lack of food.

The bones of warm-blooded animals such as birds and mammals had never been properly assessed to see if they, too, exhibit the lines.

Koehler and her team found the rings in all 41 warm-blooded animal species they studied, including antelope, deer and giraffe.

The finding "eliminates the strongest argument that does exist for cold-bloodedness" in dinosaurs, she said.

The team's analysis of bone tissue also showed that the fast growth rate of mammals is related to a high metabolism, which in turn is typical of warm-bloodedness.

"If you compare this tissue with dinosaur tissue you will see that they are indistinguishable," said Koehler.

"So this means that dinosaurs not only grew very fast but this growth was sustained by a very high metabolic rate, indicating warm-bloodedness."

  • Dakey - 2012-06-28 10:43

    Hmm, warm blooded dinosaurs. I wonder what could have killed them after all?

      Morgoth - 2012-06-28 11:21

      No Space program. Asteriods, the pesky things. :-)

      angus.stembull - 2012-06-29 03:46

      They misread the memo Noah sent out.

  • johan.blertsie.cilliers - 2012-06-28 11:19

    Does this influence the timeline in which they existed?

      Morgoth - 2012-06-28 11:27

      No, Dinosaur, meaning "terrible Lizard" had us under the impression of being lizards, cold-blooded. But as it turns out, they are closer to being avian, look at the fossils of Raptors. Hollow-tubes in the bone, just like a bird. Avian, warm-blooded. Not anything new really, Even in the movie Jurassic Park, it is mentioned that dinosuars are warm-blooded, rather than cold.

  • Provence - 2012-06-28 11:46


  • michael.holliday2 - 2012-06-28 12:00

    Another thought to consider is the possibility of certain species of dinosaurs being migratory, meaning that during times when food was scarce, they needed to move to more lush areas etc. This theory explains the rings in mammalian/warm blooded species as our metabolisms require food to function efficiently. When food is scarce our metabolisms slow down i.e less growth.

  • stephen.j.dickson.3 - 2012-06-28 12:16

    Wish there were a few T-Rex's and Raptors around to sort out our population and refugee problems.

  • masibulele.nongubo - 2012-06-28 16:52

    Ppl u knw sientists must be terminated for their lies and theories.

      poaul - 2012-06-29 08:57

      How about throwing away your phone, computer, microwave etc. all made by science...

      Morgoth - 2012-06-29 10:00

      Refreshing to hear a comment from the 12th century.

      noeln.petzer - 2012-10-04 12:21

      Troll Alert!

  • johan.erasmus.5494 - 2012-06-30 09:46

    let us call them dinotsures

      Morgoth - 2012-07-02 12:00

      Lets don't and say we did...

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