Monday, April 16, 2007

Animal of the Week -- April 16, 2007

The observant among you will have noticed the absence of Animal of the Week last week. For this I am terribly sorry, I was busy with Easter and then the internet went off-line all over the world.

To recompense for these events beyond my control, this week's animal is a monster, or rather a DINOSAUR! YAY! And not just any old dinosaur, oh no, for this week's animal is the king of the dinosaurs Tyrannosaurus rex.

I received a concerned message a couple of weeks back about the discovery of soft tissue in a T rex bone. Did that mean they had DNA? Were we going to start cloning T rex? Now, I had heard nothing of this, but a little investigation turned up that during a 2005 excavation a T rex bone had been broken and inside there appeared to be some soft tissue. Researchers originally assumed that the soft tissue was some weird mineral structure, because actual biological molecules could not possibly survive more than a million years let alone the 68 million years since the T rex had died. Or could they?

This week, the journal Science revealed a partial sequence of a protein from T rex bones found at the Hell Creek formation in Wyoming and Montana. Showing that biological molecules can survive for enormous lengths of time. When compared with other sequences of the same protein for living animals, the T rex was most similar to chickens.

T rex was alive as the reign of the dinosaurs came to an end, 67 million years ago. At 13 metres long and 5 metres tall it was one of the largest land predators to have ever lived. But not the largest. That record currently belongs to Giganotosaurus, which was likely almost 2 m longer and perhaps a tonne heavier than T rex, which lived some 30 million years before T rex in South America. The size of these huge carnivores means that they may not have been the swiftest of creatures, which makes people think they may have been scavengers rather than hunters. However, their prey were likely huge and even slower, so a lack of speed, agility, and grace would not have been necessary; however, they certainly weren't born to boogie.

But anyway, what with all this protein, might we be cloning T rex into chicken eggs any time soon. Unlikely, the protein is probably more stable than the DNA that would be needed for cloning, and even that was in tiny fragments. So sadly, there won't be theme parks populated by dinosaurs and offering T rex rides any time soon, but given their similarity to birds shown by this study, you might like to ride a white swan instead.

NB, the attached image is of course completely inaccurate, I am sure you don't need me to tell you that T rex would not have been able to stand upright as its hips and neck would have dislocated. They would have stood with their backs parallel to the ground.

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At 9:17 PM, Blogger Howard said...

Wikipedia says...

Soft tissue in dinosaur fossils

One of the best examples of soft tissue impressions in a fossil dinosaur was discovered in Petraroia, Italy. The discovery was reported in 1998, and described the specimen of a small, very young coelurosaur, Scipionyx samniticus. The fossil includes portions of the intestines, colon, liver, muscles, and windpipe of this immature dinosaur.[36]

In the March 2005 issue of Science, Dr. Mary Higby Schweitzer and her team announced the discovery of flexible material resembling actual soft tissue inside a 68-million-year-old Tyrannosaurus rex leg bone from the Hell Creek Formation in Montana. After recovery, the tissue was rehydrated by the science team.

When the fossilized bone was treated over several weeks to remove mineral content from the fossilized bone marrow cavity (a process called demineralization), Schweitzer found evidence of intact structures such as blood vessels, bone matrix, and connective tissue (bone fibers). Scrutiny under the microscope further revealed that the putative dinosaur soft tissue had retained fine structures (microstructures) even at the cellular level. The exact nature and composition of this material are not yet clear, although many news reports immediately linked it with the movie Jurassic Park. Interpretation of the artifact is ongoing, and the relative importance of Dr. Schweitzer's discovery is not yet clear.[54]

At 10:08 AM, Blogger animal_oftheweek said...

Thanks for that Howard! Showing me up again. How are the bees?


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