A mummified fossil of common species of hadrosaur was found recently in South Dakota that showed that this particular hadrosaur had a rooster-like fleshy comb on its head. Many hadrosaurs have exotic extensions of their cranial bones but this evidence that even the “boring” hadrosaurs had fleshy projections suggests that the hadrosaurs were an even more flamboyant group than previously recognized.
In an article “Dinosaur mummy’s fleshy head crest” (Ella Davies in BBC Nature) describing this dinosaur “mummy” fossil the following explanation for the remarkable preservation of this dinosaur:
Experts suggest that when an animal was instantly buried in certain sediments, decay was slowed down through a lack of oxygen and soft tissues were mineralized.
This process is called permineralization and is also responsible for the formation of petrified wood. Skin impressions and other soft tissue preservation are considered rare but are not unknown. In fact, skin impressions may be quite common but the bones are usually targeted and the mineralized material around the bones is far more difficult to examine and thus is often lost in preparation.
Instant burial is the key to soft tissue preservation
Not exactly a shocking revelation but one worth thinking about for a moment. Dinosaur bones come in many forms but most are found as just partial skeletons or only a few random pieces such as a jaw bone here and a femur there. Many bones have marks on them from scavenging. The picture formed from these bones is one of dinosaurs that have died naturally or otherwise and their bodies scavenged. For the majority of dinosaurs the flesh will have been picked off the bones or possibly decayed leaving the naked bones. If those bones get buried within a short period of time they may eventually get mineralized into the fossils we find today. But there are some bones that are found as part of complete or nearly complete skeletons. These dinosaurs may also have died and their flesh decayed prior to burial but is not likely to happen.
More rarely, a dinosaur might be buried right at the point of death in which case all the soft tissues will be preserved to some extent. In most cases this burial will be shallow and oxygenated ground water and microorganisms will lead to a rapid decay of tissues resulting in a mixing of the rotting flesh and its biomolecules with the sandy matrix. Eventually the entire sand matrix that encased the dinosaur will become rock but the impression of the fleshy tissues will not be discernible and only the bones being more resistant to decay may be preserved. However, under the right conditions (low oxygen, fast burial etc..) the flesh will remain intact long enough that the matrix around the animal will set before that decay can happen leaving the impression of where that tissue had been. This is really how bones are also preserved. Typically they are more resistant to decay and thus last long enough for minerals to slowly replace the organic components of the bone. Under conditions of quick burial in low oxygen environments, the same mineralization process can happen with soft tissues.
So what we see is that the dinosaur fossil record is consistent with a world that has experienced a diversity of preservation conditions. Some bones are found as mixed up pines of bones in river bed sediments like I observed on the dinosaur trail near Moab UT (see A tour of the dinosaur trail of Mill Canyon near Moab UT). Others are found as complete skeletons apparently buried in large sandstorms. Some are found in sinkholes and others are preserved via quick asphyxiation and burial in volcanic ash. Others appear to have drowned and been covered by flood sediments.
Soft tissue preservation is a challenge for young earth creationists.
If you come from a young earth creationist’s (YECs) background or are even just vaguely familiar with creationism then you will think I have my statement backwards. Haven’t we all been told by a multitude of creationists’ speakers that any evidence of soft tissues, cells or biomolecules in the fossil record should be scored as evidence for a recent creation. I’m going to cheat for now and not explain why I don’t think this is the case but see some brief remarks I have made in recent posts if you are interested (The mosquito that produced more than a little buzz and Young earth creationism and ancient DNA).
Rather, what struck me about this rooster-like comb on this hadrosaur is that its existence is more of curse than a blessing for YEC apologists. How can that be? Well, where I convinced that a global flood 4 to 6 thousand years ago were responsible for all the dinosaur fossils, then I should EXPECT to find soft tissues preserved to some extent as the norm rather than the exception to the rule. Why? Because the special conditions that are required for preservation of soft tissues like those found in this hadrosaur are just the kind that should have been produced by a global flood. Combine those conditions with its having happened only a few thousand years ago and you have to ask, why don’t we find skin impressions, remains of feathers, and other impressions of large organs (like these combs) and gobs of biomolecules throughout the dinosaur fossil record?
What I am saying is that if you asked a priori what you would expect to see in the fossil record had a flood destroyed all living flesh from the face of the earth in a short period of time and deposited all those organisms in what we call the geological record? I would expect to find a majority or at least a significant number of dinosaurs to be represented as complete skeletons. I would not expect to find rampant evidence of scavenging and given the fast burial I would expect to find the impressions of many parts of their bodies not just their bones since they would have been covered with their flesh intact. Since this happened not long ago I would expect to find very abundant biomolecules, possibly even intact DNA in the material around the bones, and especially in the bones, even if cells themselves were no longer present.
As I pointed out before this is not what we find in the fossil record. We find some but not much evidence of biomolecules and few cases of soft tissue preservation even if be only the impression of where soft tissues once laid. Just look at mammoths and mastodons from the fossil record. Some of these have abundant cells, DNA, hair and sometimes cellular tissues preserved. If these biomolecules could survive for 4000 years then why shouldn’t animals killed in Noah’s flood just a few hundred years earlier not also be expected to be preserved in a similar fashion?
What are your thoughts on this article by a fairly prominent YEC [Jay Wile] regarding this issue- http://blog.drwile.com/?p=11753
Basically, he argues that testing has shown the possibility of perhaps a few hundred or thousand years of preservation, but one cannot infer millions of years from that.
I saw his article and thought about replying. I’m still working on a large set of posts that will deal with soft tissue preservation and Schweitzer’s stuff in particular. In the case of the hadrosaur the tissue isn’t preserved but rather mineralized. If tissue can be mineralized then that mineralized state could potentially survive for a billion years. The question is really how quickly mineralization can happen. If trapped quickly in low-oxygen environments I don’t see why skin and other things like feathers can be mineralized within decades and thus preserved for all time. Even YECs like to show examples of quick formed fossils so they know mineralization can happen fairly quickly. The dino bone soft tissues are a different question altogether because the claim there is that some of the original biomolecules are actually preserved not just replaced by minerals. The question there is if there are conditions that can stabilize biomolecules for millions of years. The iron thing is a step toward showing how some molecules can be preserved. I would just note for now that even in the case of the dino-soft tissue the biomolecules are not the same molecules as found in the living animal but are highly modified (eg. many molecular bonds have been moved around and the molecules “simplified”) and so I think it would be accurate to say that original biomolecules might not be able to survive more than 100s of thousands of years but the modified forms (like porferin from hemoglobin) are chemically far more stable and we don’t have good ways of testing how long they can really survive.
I just noticed your article today and found it interesting that your argument against YEC is that we don’t find more soft tissue as well as complete dinosaur remains. It appears that your reasoning is that since we find soft tissue then we know that it has to exist for tens of millions of years since we all know that evolution is true. This is extremely poor reasoning. As for dinosaurs not being found complete more often and as for soft tissue not being more plentiful you need to keep in mind that the flood was violent and most likely accompanied by by powerful sunami forces sweeping across the continents (this was not a gentle flood). The whole event took a little more than a year and was then followed by gradual downturn in the violent events until we ended up with the world where we now live. Some of the creatures would have been buried during the flood and others exposed as the surface of the earth continued to change as the waters slowly abated. The bodies of some would have been exposed to the elements and, as Noah’s animals filled the earth, they would have been eaten. The reasoning, and dedication, of the evolutionist is remarkable and the reasoning is circular when it comes to these soft tissue finds. Collagen has a half life of less than 6K years and should not be present at all in a creature that is supposedly tens of millions of years old (not to mention DNA).
Hi, thanks for taking the time to respond to my article. Regarding my reasoning, I wasn’t trying to make the claim that soft tissue presence proves an old earth. I was trying to point out that soft tissues would not be surprising and even expected in a young earth model. You could say that the flood was violent and therefore disrupted tissues but your hypotheses comes with many predictions about what we will and won’t find in the fossil record. Dinosaur eggs and nests in the middle of a violent tsunami filled earth doesn’t fit the model. Nor do large termite nests or underground beehives. Billions of feces organized phyletically in layers. I agree that some bodies would be exposed some buried and so there should be different levels of preservation which we do see. Not sure where you get the idea that collagen has a half-life of 6000 years. Under what conditions? Under all conditions? Collagen derived from fossils have only represented a very small portion of the collagen protein and that part is not random but rather represents the non-acidic residues that would be packaged in such a way that chemically they should be extremely stable. It could easily be said that the collagen in general breaks down but some of the pieces of that breakdown process remain very stable much like the the breakdown products of hemoglobin.
Thank you for your reply also, I appreciate the thoughtful responses and would like to point out an error that I notice with those who hold to an ancient (millions and billions of years) earth. The first is that the creationist time frame is always forced-fit into the the evolutionary one. Therefore when an evolutionist sees dinosaur eggs and nests the assumption is that all of these creatures had to be extinct and did not live at the time of any man. The other assumption that is incorrect is that accurate age measurements can be used by way of the geologic column and radio isotope dating. In the mind of the YEC (many, perhaps not all) the dinosaurs were on the ark with Noah and would have been living after the flood and therefore able to reproduce and, of course, build nests, lay eggs, and so on. After the flood we would expect that the amount of natural disturbances, due to conditions that initiated Noah’s flood, would continue for some time, perhaps hundreds of years to a lesser degree, and that there would continue to be local flooding that would bury whatever unfortunate creatures and there nests that were in the path of those flood waters that were subsequent to Noah’s Flood.
As for collagen and its decay rate, the fact that it is a soft tissue makes it far more vulnerable to rapid decay than other materials and when we don’t find mineralization occurring this brings up more questions than answers in regards to supposed long ages of time. Under what conditions does its decay occur at 6K years? Rather than answer only that let’s also ask the question ‘under what conditions would collagen take 60 or 70 million years to decay?’. Any confident response to that additional question simply reveals a commitment to evolution; not to science.
This appears to be a simple dessicated contraction cracks normally seen in present day muds and muddy sandstone. This cracks commonly associated with basalts also seen in the sandstone nearby due to the transfer of heat suddenly which causes the phenomena
Columnar structures are seen in the mesozoic sandstone of Kutch region in India.
Thought I am not a palaeontologist I am having my own doubts about its interpretation.