Can you explain this whole T.Rex-chicken thing? What does it mean ... that T. Rex is the grand * (10^13) pa of chickens? How does this change our understanding of T. Rex or chickens?
Hi, Mike. I've not heard of a T. rex-chicken thing. What exactly are you referring to?
It is true that a great deal of evidence shows that all birds (including chickens) evolved from dinosaurs -- and so, according to the principles of modern classification, we say that they are dinosaurs, just as we say that bats are mammals rather than just that they evolved from mammals. (Thinking about bats, the flying mammals, is often helpful as an analogy when considering birds, the flying dinosaurs).
But the particular dinosaurs that birds evolved from would have been very different from T. rex -- much more like small fluffy versions of the raptors from Jurassic Park.
So T. rex is not a great grandfather to chickens, but a rather distantly related great uncle.
For those not up to date, all the fuss this week is about a paper where scientists have found some collagen fibres (a protein that among other things forms part of your bones) preserved in a 68 million year old Tyrannosaurs rex bone.
The real excitement from this paper is the fact that the collagen has been preserved at all. Geologists and biochemists have not thought that true soft tissue could last that long and survive the fossilisation process that affected the surrounding bones. Nevertheless, the collagen certainly seems to be genuine, and this brings the exciting possibility that other dinosaurian (or other ancient extinct creatures) soft tissue may one day be found.
However, the press attention has focused on the not-at-all-surprising-in-any-manner fact that the collagen found in the T. rex most closely resembles that of chickens (well, chicken were the only bird it was compared to). As ever, the media seem to think this is amazing news, when of course for the last 150 years almost all scientists have been happy with the idea that birds evolved from carnivorous dinosaurs. As a result, its no big deal that T. rex comes closest to chickens as opposed to mammals, amphibians, or reptiles.
The whole thing does not really change our ideas about dinosaur and bird evolution, but it is yet another piece of evidence to link birds to theropod dinosaurs. Still, it is an exciting discovery and is a superb piece of research.
AAB member PZ Myers has done a rather longer and more detailed review of this paper and if you want to know more, its well worth a look.
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