Soft Tissue from Dinosaurs Found: Intact Cells and Blood Vessels
The news media are abuzz with exciting reports about the discovery of soft tissues recovered from a Tyrannosaurus rex bone; see CNN, National Geographic, BBC News, MSNBC and News@Nature for examples. The soft tissue, analyzed from a thighbone unearthed in Montana, was reported by a North Carolina team led by Mary Higby Schweizer and was announced in this week’s issue of Science.1
The bone contained remnants of blood vessels that were still soft and flexible when separated from the matrix, and even individual cells: “osteocytes with internal cellular contents and intact, supple filipodia that float freely in solution,” the authors say. Leading dinosaur paleontologist Jack Horner described the bone as “a fantastic specimen.” The discoverers also found soft tissues in two other tyrannosaurs and one hadrosaur from the Hell Creek, Montana site. No one seems to be questioning the assumed age of the specimens being 70 million years old, even though the “geochemical and environmental factors” that could have preserved the tissues are “as yet undetermined,” and extend to the molecular level:
Whether preservation is strictly morphological and the result of some kind of unknown geochemical replacement process or whether it extends to the subcellular and molecular levels is uncertain. However, we have identified protein fragments in extracted bone samples, some of which retain slight antigenicity. These data indicate that exceptional morphological preservation in some dinosaurian specimens may extend to the cellular level or beyond.
(Emphasis added in all quotes.)
Erik Stokstad in the same issue of Science2 says that the vessels, still flexible and elastic, are not fossilized. The announcement of intact cells is leading some scientists to think they may be able to extract DNA from them (although recreating Jurassic Park is out of the question). Principal investigator Schweitzer said she was shocked at the find. She didn’t believe it till they repeated the extraction process 17 times. As a control, they repeated the same process on extant ostrich bones and recovered soft tissues that were “virtually indistinguishable” from those of the dinosaur.
It is not yet clear whether the original molecules in the tissues and cells were preserved or were replaced by other compounds. Earlier claims of original tissue in other kinds of multi-million-year fossilized organisms turned out to show replacement. Schweitzer told the BBC, however, that “It still has places where there are no secondary minerals, and it’s not any more dense than modern bone; it’s bone more than anything.” As to DNA, Stokstad quotes one expert who said, “the likelihood is probably next to none” that intact DNA could have survived for 68 million years, even if the bone was protected in stable, dry, subzero conditions all that time. The BBC reporter agrees that “the ‘life molecule’ degrades rapidly over thousand-year timescales, and the chances of a sample surviving from the Cretaceous are not considered seriously.” Schweizer is seeking funds to do mass spectrometry on the tissues and find out.
1Schweitzer et al., “Soft-Tissue Vessels and Cellular Preservation in Tyrannosaurus rex,” Science, Science, Vol 307, Issue 5717, 1952-1955, 25 March 2005, [DOI: 10.1126/science.1108397].
2Erik Stokstad, “Tyrannosaurus rex Soft Tissue Raises Tantalizing Prospects,” Science Vol 307, Issue 5717, 1852, 25 March 2005, [DOI: 10.1126/science.307.5717.1852b].
This appears to falsify, in one dramatic swoop, the claim that dinosaurs died out 65 million years ago. Why don’t the scientists admit it? It’s uncanny how all the reports treat the 70 million figure like an unquestionable fact, despite the clear implications of this discovery. Notice how the BBC treats the date like dogma:
In the hotly contested field of dino research, the work will be greeted with acclaim and disbelief in equal measure.
What seems certain is that some fairly remarkable conditions must have existed at the Montana site where the T. rex died, 68 million years ago.
Seems certain to whom? Not to people with their heads screwed on, who have refused to take the oath of loyalty to the Darwin Party, or signed on to the Committee to Protect the Geologic Column at All Costs. We’ll have to see if the NCSE censors this paper, preventing teachers from showing it to their students, to protect their sensitive minds from anxiety when they compare it with their textbooks.
. Making the excuse that the process of fossilization is not well understood is pitiful, and imagining these Montana sediments escaping millions of years of mountain uplift, erosion and climate change is a big stretch. Though airtight amber sometimes preserves all the details of an insect, it is incredibly improbable that soft, pliable tissues from a large dinosaur could be preserved in a sedimentary matrix for 10,000 years, let alone 70 million. Somebody ought to press the point. The BBC explains why: “Normally when an animal dies, worms and bugs will quickly eat up anything that is soft. Then, as the remaining bone material gets buried deeper and deeper in the mud, it gets heated, crushed and replaced by minerals, turning it to stone.” Schweitzer said in the NG coverage that “our theories of how fossils are preserved don’t allow for this [soft-tissue preservation].” The pathetic response of some scientists, upon hearing this announcement, is that the soft tissue recovery might help them construct better phylogenetic trees. They seem oblivious to the fact that the data threaten to cut off the long-age limb they are sitting on.
Here is an opportunity for young-earth creationists to make a strong case. It’s easier to prove an upper limit than a lower limit: e.g., that under the best of conditions, cells or blood vessels could not be older than a maximum number of years based on lab observations. No reader could claim by observation that they could last millions of years. Thus, the young-age position is more conservative, cautious and empirically based. Someone should also apply carbon dating to the tissues and see if any C-14 is present. It would be below the detection threshold if the bone is as old as claimed. Watch the efforts to find out if DNA is still present, which “cannot survive that long” according to Derek Briggs in the News@Nature article. These are two predictions that can be tested.
This find is making it easier to believe that dinosaurs actually lived in relatively recent times and were buried quickly by a watery catastrophe just as a Biblical chronology indicates. Dramatic as this announcement is, it is not the first. Creationists have followed up on soft-tissue claims for years. In 1994, Buddy Davis and a team endured danger and hardship recovering hadrosaur bones in Alaska that contained unfossilized tissue; their story is published in The Great Alaskan Dinosaur Adventure. Then there was the announcement in all the papers 10/15/2002 about mummified dinosaur remains. Even more remarkable was the BBC News story about mummified soft parts found in a crustacean claimed to be 511 million years old – over seven times older than the dinosaurs on the evolutionary scale (see 07/20/2001 entry). That such announcements are rare in the secular literature does not mean that the fossils are rare; Jack Horner said in the NG article that other dinosaurs are “probably similarly preserved,” but workers in the field are usually reluctant to damage dinosaur bones to look inside (maybe partly because they don’t expect to find soft tissue after millions of years). What this story illustrates is how scientists tend to find what they expect to find, look for what they need to find, and ask the questions prompted by their worldview. It’s instructive to notice who was surprised by today’s announcement.