Stories tagged soft tissue

Apr
13
2007

Two years ago, everyone was talking about the work of paleontologist Mary Schweitzer: she noticed that thin slices of a 68-million-year-old fossil femur from a Tyrannosaurus rex looked like they still contained soft tissue. (See photos of the bone.) Using antibodies to the collagen protein, she showed that the bone still contained intact collagen molecules—the main component of cartilage, ligaments, and tendons.

Hello, dinos?: A new study shows that preserved collagen from a 68-million-year-old Tyrannosaurus rex is similar to that of chickens. (Photo courtesy Danelle Sheree)
Hello, dinos?: A new study shows that preserved collagen from a 68-million-year-old Tyrannosaurus rex is similar to that of chickens. (Photo courtesy Danelle Sheree)

She used antibodies to a type of collagen extracted from chickens. The fact that the antibodies stuck suggested that T. rex collagen is similar to that of birds. And when she compared the preserved soft tissue to that of modern animals, the closest match was an emu—a flightless bird.

To learn more about the collagen in the T. rex bones, Schweitzer worked with John Asara, a chemist at Harvard University, to analyze it using mass spectrometry.

The Economist describes the technique this way:

This technique identifies molecules (or fragments of molecules) from a combination of their weight and their electric charges. Knowing the weights of different sorts of atoms (and of groups of atoms that show up regularly in larger molecules, such as the 20 different amino acids from which proteins are assembled) it is usually possible to piece together fragments to form the profile of an entire protein.

When Asara compared the profile he'd created to proteins from living animals, the closest matches were to chickens and ostriches. (Schweitzer and Asara's study was published in the April 13, 2007, issue of the journal Science.)

Many paleontologists already believed, based on fossil bones, that birds are dinosaurs or their descendants. But this new paper provides even more evidence of the fact.

Buzz stories on the subject from last year:

Recent news articles:

Jul
26
2006

Maria McNamara of University College Dublin, and colleagues in the UK, Spain, and US, have recovered bone marrow from 10-million-year-old fossilized bones of frogs and salamanders found in Spain.

The marrow was preserved in 3D, and still has its original texture and color. Scientists think they may be able to extract traces of protein and DNA.

Even more interestingly, the fossils prove that ancient salamanders produced blood cells in their bone marrow. Modern salamanders, on the other hand, produce blood cells in their spleens.

Last year, US scientists recovered some tissue resembling blood vessels from a 65-million-year-old Tyrannosaurus rex fossil. They also found traces of what appeared to be red blood cells. (More on the T. rex find.)

And now that they're looking, scientists think they may find examples of preserved bone marrow in many fossils, raising the possibility of analyzing the proteins and DNA of lots of long-extinct organisms.