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.

Your Comments, Thoughts, Questions, Ideas

Anonymous's picture
Anonymous says:

I’m not a scientist but, I was wondering; will the discovery of soft tissue in these fossils drive science to reconsider not only the process of fossilization but also the age of the fossils?

posted on Wed, 08/23/2006 - 10:30am
China Man's picture
China Man says:

Right. Scientists were pretty much agreed before this recent discovery and the T-rex discovery that it was impossible for soft tissue to last much longer than 300,000 to 500,000 years. Now we are looking at fossils 10 million years and older that still have soft tissues inside. Something in the theory has to budge: either the age of the fossils or the length of time that soft tissue can remain intact. It will be interesting to see what theory ends up changing. In the initial flush of discovery it seems that scientists immediately assumed they were wrong about the length of time that soft tissues can last; chalk it up to Occam's razor. (Occam's razor says basically that if you have a discovery, you should explain it in the most simple way possible. So for example, it is easy to say that soft tissues can last longer, but if we want to say that the fossils are not as old as we thought, that will require a ton of recalculating, book changing and what-not.) But it will be interesting to see what happens as the scientific community has time to study and theorize about this a little more.

posted on Mon, 04/16/2007 - 10:34am
Kristi Curry Rogers's picture
Kristi Curry Rogers says:

The recovery of extremely ancient soft tissues is interesting because of what it means for how fossilization happens - our models of fossilization tell us that something gets buried, soft parts decay away, and minerals replace or fill voids, essentially turning bone to stone. The reality is that preservation is far more complex than that - think of all the kinds of fossils there are out there (from peat bogs, to permafrost, to collapsed dunes, to impressions of leaves and carbonized other soft parts) - this exciting work on the bone of T. rex provides another twist to this interesting puzzle of how things make it from the land of the living (the biosphere) to the land of the dead (the lithosphere). No real "theory" has to change here - the soft parts and proteins that the team has recovered in T. rex offer an interesting, different insight into the environment of fossilization. Parsimony (another word for the simplest answer is right, or Occam's Razor) is a principle that holds true here - there are soft tissues that are far older than 500,000 years that have been preserved (including chitin in 25 million year old fossils). What difference does a few million years make? I would argue that no one really knows, and that is the great thing about how science works. Our ideas DO change as new discoveries are made - the important thing is that those ideas be testable. It is easy, as you say, to say that soft tissues can last longer. The only reason that we thought soft tissues couldn't persist is literally because no one had really looked before. Now that we know it might be there, and our technology is advanced enough to detect it, I can guarantee that scientists will be out putting these data to the test, which is, after all, the nature of science.

Kristi Curry Rogers, Ph. D.
Curator of Paleontology
Science Museum of Minnesota

posted on Wed, 04/18/2007 - 9:56am

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