Dinosaur Bone Soft Tissue Questioned, Defended
The subject of soft tissue in dinosaur bones came up at the Society of Vertebrate Paleontology Meeting earlier this month, reported Science.1 Mary Schweitzer was there, defending her spectacular claim that she had discovered both medullary bone (06/03/2006) and soft, pliable blood vessels and cartilage in a T. rex leg bone (03/24/2005). Doubters, however, brought up another possibility:
But skeptics have another, less sexy, explanation for the tissue: the replacement of original tissue by microbes. Thomas Kaye, a full-time amateur paleontologist in Prospect Heights, Illinois, examined wellpreserved bone from four kinds of late-Cretaceous dinosaurs using a scanning electron microscope and sees signs that microbes have replaced the original tissue. During 200 hours of observations, Kaye found hollow vascular canals like those of Schweitzer’s specimen. But he also discovered evidence that microbes had moved through a thick film. In some samples, this film had dried out and had a carbon-14 date of 1960-1970. As for the structures resembling cells called osteocytes, Kaye and colleagues think they could be microbes that filled in a void in the bone.
Hans Larsson, a paleontologist at McGill University in Montreal, Canada, says the theory of microbial replacement is “totally logical” and that carbon-14 dating should be done to rule out modern biofilms. The debate is expected to continue. “The proof is going to be tricky,” Larsson says. “It’s going to take years.”
Schweitzer defended her claims. Further studies in her lab have shown “what appears to be collagen, which could be authentic dinosaur protein.” She even found short sequences of peptides that match collagen. The patterns of collagen match those of a living emu. David Martill (U of Portsmouth, UK), a colleague not present at the meeting, remarked, “Looks like collagen, behaves like collagen, and it’s 68 million years old. How cool is that?” More evidence was produced that cannot be so easily explained away:
The egg-laying tissue, called medullary bone, was previously known only in living birds. Ovulating females rapidly create this mineral-rich tissue inside their legs and other bones as a storehouse for calcium for making eggshell. In a paper in Science (3 June 2005, p. 1456), Schweitzer and her colleagues compared the fossilized leg bone of a roughly 70-million-year-old Tyrannosaurus rex with modern ostrich bone, showing many similarities.
Now Sarah Werning and Andrew Lee, graduate students at the University of California, Berkeley, and paleontologist Paul Bybee of Utah Valley State College in Orem have found medullary bone in two other kinds of dinosaurs. Looking at a nearly 150-million-year-old tibia of the large predator Allosaurus fragilis from Utah, the trio found a layer of bone in which the tissue was disorganized and replete with traces of blood vessels, suggesting it had grown quickly. “It was really convincing,” says paleontologist Martin Sander of the University of Bonn, Germany.
Not only that, “The same pattern turned up in a femur and tibia of an approximately 110-million-year-old Tenontosaurus tilletti from Montana.” Yet this species is a member of the Ornithischia, part of a deep split from the Saurischia, to which the other specimens belonged. Since both major groups now are found with medullary bone, evolutionists are forced to believe this specialized tissue formation process originated in a common ancestor far earlier. Werning remarked, “This really pushes [the origin] back.”
1News focus, “Soft Tissue in Dinosaur Fossils? The Evidence Hardens,” Science, 10 November 2006: Vol. 314. no. 5801, p. 920, DOI: 10.1126/science.314.5801.920.
The report hints at a lively meeting. It is certainly fair, and even desirable, for scientists to propose alternative explanations for surprising discoveries. The soft-tissue claim was a huge surprise. The burden of proof is on Schweitzer (though she seems to be holding the mountaintop well). But merely tossing out a what-if rebuttal can be a dodge. The research with this material must continue to be pursued diligently and carefully, because the implications are enormous. Look again at the pictures (MSNBC). Kids at Science Buzz seem jazzed by the announcement. The high-res photos on this Science Museum of Minnesota website sure look like real tissues.
How plausible is this new alternative suggestion that microbial biofilms are merely mimicking the soft tissue? Consider what we already know, and questions that should be leveled against the microbe hypothesis:
- Surprise effect: This was an unexpected discovery by a scientist with no axe to grind against long ages or evolution.
- Microbial longevity: Are they claiming these microbes have been living and reproducing in the bone for 68 million years?
- Microbial stasis: If the answer to #2 is yes, have the microbes remained locked in position all that time so that they still resemble the original tissues they replaced?
- Collagen: Doesn’t the identification of collagen peptides falsify the microbe hypothesis?
- Dating: Could not the recent carbon-14 date represent contamination since excavation?
- Treatment: How could microbial biofilm mimic ostrich tissue after treatment, and in solution?
- Comparison: How could microbes survive lab extraction processes and imitate soft tissues, blood vessels and blood cells, so as to fool a trained scientist comparing it side-by-side with ostrich tissue?
- The medullary bone is not disputed; how could that survive 68 million years? (06/03/2006)
- New medullary bone finds are said to be even older: how could those survive 150 million years?
- How could the medullary bone system, and its linkage to egg-laying, evolve in an even-older ancestor?
- Why would the ancient medullary bone resemble that of a modern emu, if evolution implies constant change?
- Are critics merely proposing a story to avoid the implications of the find, i.e., that these tissues cannot be millions of years old?
The article advised that further tests “should” be done to rule out modern biofilms. By all means. Otherwise, this gives a fake foothold to skeptics to dismiss one of the two most astonishing dinosaur discoveries of the past year. Extraordinary claims may require extraordinary evidence, but the protagonist has made a strong case. Now it appears the critics’ rebuttal is looking extraordinary, so the requirement cuts both ways.
Notice another example of evolutionary question-begging in the article: “At the meeting, another group reported further evidence of egg-laying tissue, suggesting that it evolved early in dinosaur history.” It suggests nothing of the kind. The “further evidence” had nothing to do with Darwinism. It’s fragile medullary bone, part of a complex system that supplies calcium during egg-laying and does not normally fossilize, and now other researchers have found more examples in other species, in other locations, some more than twice the assumed age of the first one. Moreover, these samples come from two major groups of dinosaurs.
Now, in order to maintain their story, they have to push the imaginary common ancestor of this complex system way, way back into the mythical past. This should have astonished, embarrassed and humbled the evolutionists. So what did they do, instead? They twisted the evidence into their tale, like cave men taking a manuscript they do not understand and using it to stoke their campfire, or like pagan priests seeing a meteorite fall, and offering it in the temple of their idol.
If the evolutionists are going to take their jolly time to resolve this debate, creationists should put the pressure on. Creation dinosaur digs (e.g., 05/21/2002, 07/23/2003) with well-trained leaders should get out and find more soft-tissue evidence, documenting and photographing everything carefully from start to finish, till no doubt remains. The burden of proof needs to shift back to the people who made the first extraordinary claim: that the mighty beasts of the earth, and all living things, with all their complex systems, made themselves.