Category: Age of the Earth

In 2005, Dr. Mary Schweitzer shocked the paleontology community by reporting that she had found soft tissue in a Tyrannosaurus fossil that was thought to be 65 million years old.¹ One type of soft tissue structure found appeared to be branching blood vessels like those shown in the picture above. The idea that blood vessels could have remained soft for millions of years is contrary to everything we currently know about biomolecules and their decay, so many in the paleontology community searched for some other explanation of Dr. Schweitzer’s find.

For example, its possible that despite its appearance, the structure isn’t composed of blood vessels at all. Instead, it could be the result of a recent colonization of bacteria or fungi. After all, when the blood vessels in a bone decay away, the “tunnels” in which they were housed remain. What if rather recently, a colony of bacteria took up residence in those same tunnels? These organisms often leave a slime (called a biofilm) behind, and if they left it in those “tunnels,” the biofilm would take the shape of the “tunnels.” That would make the biofilm look and behave a lot like blood vessels.

Such an explanation seemed to get some support back in 2008, when a major article was published in PLoS ONE.² In that article, researchers reported on a survey they had done of many dinosaur bones. They found several examples of what appeared to be soft tissue in those bones, and they submitted some of those samples for carbon dating. The dating indicated that the samples were of very recent origin. In addition, they compared their samples to modern biofilms and modern collagen (a protein not made by bacteria). Their samples of apparent tissue resembled modern biofilms much more than modern collagen, so they concluded:

When biofilms coat a substrate, and that substrate is subsequently removed, the biofilm will retain much of the original morphology. This can explain the quantity and similarity of structures found in fossil bone and indicates that these structures are unlikely to be preserved dinosaurian tissues but the product of common bacterial activities.

Since then, however, the analysis of a variety of soft tissue found in dinosaur bones has lent a lot of support to the idea that these tissues are not biofilms, but are genuine dinosaur tissue (see here, here, here, and here). It seems that the definitive paper has finally been published, showing, at minimum, that soft blood vessels found in one dinosaur bone do come from the dinosaur itself.

Continue reading “Soft Blood Vessels from a Dinosaur Fossil”

In early June, an extraordinary paper was published in the journal Nature Communications. The paper is free to read, so I encourage you to take a look at it. The authors of the paper begin by offering a summary of the various discoveries of soft tissue in dinosaur bones. They then make this important point:

Models proposed to account for such preservation indicate that it should be the exception rather than the rule. In particular, it has long been accepted that protein molecules decay in relatively short periods of time and cannot be preserved for longer than 4 million years. Therefore, even in cases where organic material is preserved, it is generally accepted that only parts of original proteins are preserved and that the full tertiary or quaternary structure has been lost.

If you aren’t familiar with the terms, “tertiary” and “quaternary” structure refer to details that determine the three-dimensional shape of a protein, which is very important for its chemical function. Essentially, the authors of the paper are saying that the individual chemicals (called amino acids) that make up the protein might still be around after 4 million years or so, but the protein will be highly degraded.

So, the authors say that according to the prevailing wisdom right now, soft tissue preservation in dinosaur bones (which are supposed to be much, much older than 4 million years) should be very rare. They decided to test this idea, and not surprisingly, they found that it was wrong. How did they test it? They looked at eight dinosaur fossils found in Cretaceous rock, which is supposed to be between 145 million and 65 million years old. The authors suggest that the fossils are 75 million years old. The important point, however, is that these bones were definitely not well-preserved. As one of the authors said in a news report:

They’re very scrappy, individual broken bones. I can’t even tell you what dinosaur they come from.

What they found in these “scrappy” bones is surprising, at least if you think they are 75 million years old.

Continue reading “Is Soft Tissue Common in Dinosaur Bones?”

NOTE: Even more data have been published indicating that the sun does not affect radioactive decay rates.

In previous articles (see here, here, and here), I discussed some very interesting results that were coming from different labs. These results indicated that the half-lives of some radioactive isotopes vary with the seasons. They seemed to imply that the sun was somehow affecting the rate of radioactive decay here on earth. This made the results controversial, because there is nothing in known physics that could cause such an effect.

One criticism of the studies was that weather could be the real issue. Even though labs are climate-controlled, no such control is perfect. Humidity, pressure, and (to a lesser extent) temperature can all vary in a nuclear physics lab, so perhaps the variations seen were the result of how the changing weather was affecting the detectors. However, the authors used several techniques to take changing weather into account, and all those techniques indicated that it couldn’t explain the variations they saw. The authors were (and probably still are) convinced that they were seeing something real. I was as well. In fact, one of my posts was entitled, “There Seems To Be No Question About It: The Sun Affects Some Radioactive Half-Lives.”

Well, it looks like there is some question about it. Two scientists from Germany decided to measure the rate of radioactive decay of the same isotope (Chlorine-36) that was used in some of the previously-mentioned studies. However, they decided to use a different experimental technique. The studies that showed variation in the rate of radioactive decay used a Geiger-Muller detector (often called a “Geiger counter”) to measure the radioactive decay. The two scientists who authored this study used a superior system, based on liquid scintillation detectors. The authors contend (and I agree) that the response of such detectors is much easier to control than the response of Geiger-Muller detectors, so their results are more reliable. They also used a particular technique, called triple-to-double coincidence ratio, that reduces “noise” caused by background radiation. When doing detailed measurements of radioactive decay, this is one of the standard techniques employed.

Continue reading “Maybe the Sun Doesn’t Affect Radioactive Decay Rates”

In March of 2013, I wrote about soft tissue that had been found in the fossilized remains of a Triceratops horridus, which is supposed to be about 65 million years old. One of the scientists who found the tissue and published a paper on it in the peer-reviewed literature¹ (Mark Armitage) was subsequently fired from his position at California State University Northridge. He has sued the university, claiming that he was fired because of his religious views. This update isn’t about the lawsuit; I have no knowledge of how that is going. Instead, this update is about the fossil itself.

Samples from the fossil were sent to Dr. Alexander Cherkinsky at the University of Georgia’s Center for Applied Isotope Studies for dating via the carbon-14 dating method. Since the current half-life of carbon-14 is “only” about 5,700 years, there should be no detectable levels of it in the original parts of the fossil, if the fossil is millions of years old. However, Dr. Cherkinsky’s lab found very detectable levels of carbon-14. In fact, there was so much carbon-14 in the fossil that it was given a date of 41,010 ± 220 years.² This is well within the accepted range of carbon-14 dating, and it is actually younger than other carbon-14 dates reported in the scientific literature.³

While this is an interesting result, it is not as interesting as I would like it to be. I wanted the soft tissue that was found in the fossil to be dated, but it was not. Instead, the fossil’s bioapatite (a mineral found in bone) was dated. According to a 2009 report in the journal Radiocarbon, bioapatite is actually preferable to soft tissue in many cases. As the report states:⁴

Contamination of the organic fraction in the process of the burial or during museum preservation treatment generally prohibits the use of the collagen fraction for dating. Our investigation has shown that the pretreatment of bone with diluted acetic acid following a proscribed technique allows the separation of the bioapatite fraction from diagenetic carbonates.

Please note that “diagenetic carbonates” refer to contaminants that occur during the fossilization process. The report then gives a method by which original bioapatite can be extracted from a fossil. Dr. Cherkinsky’s lab followed that procedure. Since the lab specifically reported a date for the fossil’s bioapatite, I have to assume that the investigators who actually did the preparation and dating think they were dating the fossil’s original bioapatite, not a mixture of bone and contaminants.

Continue reading “An Update On The Triceratops Fossil That Contained Soft Tissue”