What makes this find so significant? Using CT scans, researchers have been able to measure the muscle mass in the animal's tail, allowing them to do calculations to give more accurate estimates of its total mass and proportions. Also, data on muscles helps refine models of how dinosaurs moved. This specimen shows that hadrosaurs were more muscular, and may have moved faster, than previously thought.
Also, it is possible to measure the size of the scales on the fossilized skin. This specimen has scales of varying sizes. (Edit: I originally had a blurb about this species possibly being able to change colors, but Zach has pointed out a misinterpretation, the differently sized scales just mean it could have had a variety of different colors but not that one scale could change into a different color. See the comment for his great explanation on how color works in reptile integument!). This is a very exciting discovery, because complex patterns and colorful displays are very important in social dynamics such as mating, dominance, etc.The announcement is ever-so-conveniently timed, because on December 9 the National Geographic Channel will air a documentary about this specimen, Dino Autopsy. I'll be studying for finals that weekend, it's so considerate of them to give me yet another way to procrastinate... ;)
Read the ScienceDaily report for the full story!
6 comments:
No, I think the coloration thing they're talking about at National Geographic implies that the animal was not monochrome. That is, different scale sizes were different colors. So a band of large scales was, say, red, while the surrounding smaller scales were brown. Or something.
I'm not sure how much scale morphology is involved in color changing. I've had anoles and chameleons, both of which change color frequently, but anole scales aren't much different from iguana scales, and chameleon scales are simple overlapping or interlocking structures.
Wikipedia has more to say on this topic:
Chameleons have specialized cells, collectively called chromatophores, that lie in layers under their transparent outer skin. The cells in the upper layer, called xanthophores and erythrophores, contain yellow and red pigments respectively. Below these is another layer of cells called iridophores or guanophores, and they contain the colourless crystalline substance guanine. These reflect, among others, the blue part of incident light. If the upper layer of chromatophores appears mainly yellow, the reflected light becomes green (blue plus yellow). A layer of dark melanin containing melanophores is situated even deeper under the reflective iridophores. The melanophores influence the 'lightness' of the reflected light. All these different pigment cells can rapidly relocate their pigments, thereby influencing the colour of the chameleon.
Willo (the dino with a heart) is on display at the Museum in Raleigh, if you arrive early or leave late on Sunday, we can all go to see it (and the Acrocanthosaurus, of course).
Zach: Thanks for the clarification on that, I appreciate it! I should have read the news report a little more critically. The idea of multicolored dinosaurs still allows for dimorphism, display, etc, but is not quite as "cool" as changing colors as with chromatophores. We've covered different integument types of different vertebrate classes in one of my courses this semester, the different mechanisms involved are extremely fascinating. One of my favorite books is "In the Blink of an Eye" by Andrew Parker, it talks extensively about the evolution of vision and what a drastic impact it could have had on many aspects of animal life thereafter. I think his idea that it sparked the "big bang" of evolution is debatable, but it's still a thought provoking read and a great primer on vision and color.
Bora: Really? I am intrigued...
Yes, check their website:
http://www.naturalsciences.org/
and if you can, add another day for the trip and we'll go!
Re hadrosaur speed: A lot has been said in the media flurry concerning the animal, but what's been said about speed isn't particularly convincing. A large posterior may be muscular, but it doesn't necessarily mean that it will lend more speed.
And where outrunning T. rex is concerned: don't count your mummified tyrannosaurs before they hatch. :)
Otherwise, it's a great find!
I agree, Emile, I thought the "outrunning T. rex" idea was not fully substantiated (they could just as easily be wrong about theropod speeds as they were about hadrosaurs, who knows?), which is why I didn't mention it in my post. Every new discovery definitely raises plenty of suggestions that are interesting to think about!
Post a Comment