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Dinosaur soft tissue explanation?

by nlsherrill
Tags: dinosaur, explanation, soft, tissue
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nlsherrill
#1
Dec2-10, 12:59 PM
P: 322
I have read/heard about this for awhile now and I haven't really read any good explanations for this. Does anyone know how exactly soft tissue could be preserved for so long?....assuming it is indeed >60 million years old?
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Evo
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Dec2-10, 01:30 PM
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Quote Quote by nlsherrill View Post
I have read/heard about this for awhile now and I haven't really read any good explanations for this. Does anyone know how exactly soft tissue could be preserved for so long?....assuming it is indeed >60 million years old?
Please post a link to your source, I have heard nothing about preserved dinosaur soft tissue. Do you mean imprints of the tissue?
bobze
#3
Dec2-10, 01:47 PM
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Quote Quote by nlsherrill View Post
I have read/heard about this for awhile now and I haven't really read any good explanations for this. Does anyone know how exactly soft tissue could be preserved for so long?....assuming it is indeed >60 million years old?
Assuming your talking about the T-rex "soft-tissue", as described here, it isn't really soft tissue. The media pretty much (as normal on scientific press releases) dropped the ball.

It was a mineral matrix, that once dissolved in acid and treated with lots of chemicals yielded a matrix reminiscent of soft-tissue--Enough so, to give us a little insight to dinosaur tissue. Its not like the media seems to imply that it was a chunk of "flesh".

madcat8000
#4
Dec2-10, 04:47 PM
P: 112
Dinosaur soft tissue explanation?

I think nlsherrill is refering to an article in this months Scientific American, page 62, "Blood From Stone" - Mary H. Schweitzer The thrust of the article is they believe that they are microscopic organic(soft) remains like osteocytes, red blood cells, and various fibers. It is written very cautiously never saying they have anything specific, while beating you over the head with evidence. It appears to me that they just cant get enough money to do a proper study on it and are trying to stir up interest to aquire said money.
nlsherrill
#5
Dec2-10, 07:05 PM
P: 322
Well I have seen it talked about on a few websites, and my universities web page not to long ago, but I think this is the same story.

http://www.msnbc.msn.com/id/7285683/...ience-science/

I didn't realize that was so long ago...As the page seems to indicate, the scientists took pictures of what appears to be some "meat" of the dinosaur femur.

Anyway, I just haven't read any cold hard facts about the finds and was curious to see if they had explained why the soft tissue was preserved, which was previously thought to be impossible.
Evo
#6
Dec3-10, 11:23 AM
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Interesting, they removed the minerals.

Schweitzer said that after removing the minerals from the specimen, the remaining tissues were soft and transparent and could be manipulated with instruments.

The bone matrix was stretchy and flexible, she said. Also, there were long structures like blood vessels. What appeared to be individual cells were visible.

She did not know if they were blood cells. "They are little round cells," Schweitzer said.

She likened the process to placing a chicken bone in vinegar. The minerals will dissolve, leaving the soft tissues.
madcat8000
#7
Dec3-10, 11:51 AM
P: 112
Student, if you are saying that the structers inside are just very well fossilized then what explains the fact that they were able to get antibody reactions to them.
Ophiolite
#8
Dec8-10, 09:27 AM
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Quote Quote by Evo View Post
Please post a link to your source, I have heard nothing about preserved dinosaur soft tissue. Do you mean imprints of the tissue?
There is this 2007 Science article: "Analyses of Soft Tissue from Tyrannosaurus rex Suggest the Presence of Protein".

A National Geographic article reports on that study and a further one that yielded the antibody reactions referred to by madcat8000.

McNamara et al report in the Proceedings of the Royal Society, October 14 2009, on very well preserved tissue from an 18 myr old salamander and conclude that "Our results provide unequivocal evidence that high-fidelity organic preservation of extremely labile tissues is not only feasible, but likely to be common."

And we have this:

Schweitzer, M. et al " Biomolecular Characterization and Protein Sequences of the Campanian Hadrosaur B. canadensis", Science 1 May 2009

Abstract
Molecular preservation in non-avian dinosaurs is controversial. We present multiple lines of evidence that endogenous proteinaceous material is preserved in bone fragments and soft tissues from an 80-million-year-old Campanian hadrosaur, Brachylophosaurus canadensis [Museum of the Rockies (MOR) 2598]. Microstructural and immunological data are consistent with preservation of multiple bone matrix and vessel proteins, and phylogenetic analyses of Brachylophosaurus collagen sequenced by mass spectrometry robustly support the bird-dinosaur clade, consistent with an endogenous source for these collagen peptides. These data complement earlier results from Tyrannosaurus rex (MOR 1125) and confirm that molecular preservation in Cretaceous dinosaurs is not a unique event.

It seems likely that this will become an expanding field for two reasons: 1) analytical techniques are now sophisticated enough to work with this material; 2) researchers will now actively seek out examples.
Greg Bernhardt
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Nov30-12, 01:02 PM
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Gotta bump this to hear any further developments. I've recently been reading about this. Just to clarify, was what they found actual tissue/collagen, as most articles seem to describe or was it a mineral matrix. Whatever that is. I'm having difficultly figuring out exactly what was found.

Evo
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Nov30-12, 01:29 PM
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Quote Quote by Greg Bernhardt View Post
Gotta bump this to hear any further developments. I've recently been reading about this. Just to clarify, was what they found actual tissue/collagen, as most articles seem to describe or was it a mineral matrix. Whatever that is. I'm having difficultly figuring out exactly what was found.
It seems bobze nailed it in post #3.

This is the latest reference to Dr Schweitzer's work.

http://serc.carleton.edu/research_ed...inthenews.html

ABSTRACT

Six independent lines of evidence point to the existence of heme-containing compounds and/or hemoglobin breakdown products in extracts of trabecular tissues of the large theropod dinosaur Tyrannosaurus rex. These include signatures from nuclear magnetic resonance and electron spin resonance that indicate the presence of a paramagnetic compound consistent with heme. In addition, UV/visible spectroscopy and high performance liquid chromatography data are consistent with the Soret absorbance characteristic of this molecule. Resonance Raman profiles are also consistent with a modified heme structure. Finally, when dinosaurian tissues were extracted for protein fragments and were used to immunize rats, the resulting antisera reacted positively with purified avian and mammalian hemoglobins. The most parsimonious explanation of this evidence is the presence of blood-derived hemoglobin compounds preserved in the dinosaurian tissues.
http://www.pnas.org/content/94/12/6291.full.pdf+html
Greg Bernhardt
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Nov30-12, 01:31 PM
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Thanks Evo! I will look at those links!

Here is what I have found that was released last month that got me thinking:

Analysis of Dinosaur Bone Cells Confirms Ancient Protein Preservation
http://news.ncsu.edu/releases/tpschweitzer-bone/

Molecular analyses of dinosaur osteocytes support the presence of endogenous molecules
http://www.sciencedirect.com/science...5632821201318X
Evo
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Nov30-12, 01:44 PM
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Quote Quote by Greg Bernhardt View Post
Thanks Evo! I will look at those links!

Here is what I have found that was released last month that got me thinking:

Analysis of Dinosaur Bone Cells Confirms Ancient Protein Preservation
http://news.ncsu.edu/releases/tpschweitzer-bone/

Molecular analyses of dinosaur osteocytes support the presence of endogenous molecules
http://www.sciencedirect.com/science...5632821201318X
Thanks Greg, I love dinosaur stuff.

That's better than my link!!
Darwin123
#13
Nov30-12, 03:34 PM
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Quote Quote by nlsherrill View Post
I have read/heard about this for awhile now and I haven't really read any good explanations for this. Does anyone know how exactly soft tissue could be preserved for so long?....assuming it is indeed >60 million years old?
The article that you posted talked about the preservation of organic molecules millions of years after the animals died. Although this is rare, it does not violate any known laws of chemistry. There is no known law claiming that the chemicals in tissues have to disappear after a long time.

The main reasons of tissues decay is because microorganism eat the molecules. If the soft tissue is isolated from microorganisms soon after death, then the molecules can live a long time.

Proteins in an organism left to them selves are generally unstable because they polymerize. The smaller molecules start sticking together to form very long molecules. These long molecules often resist digestion by microorganisms. However, smaller segments of these long molecules have the same shape as the smaller molecules that made up the polymer. For example, if an antibody sticks to another protein molecule, the active site on the molecule may remain active. Unless some tough microorganism dissolves the polymer, the antibody may remain active a long time.

This is probably what happened to the tissues of the dinosaur. The tissues didn’t remain intact. Most of the molecules probably polymerized. This happens in mummies and other preserved bodies. Minerals definitely seeped into the tissues. Note that these tissues did not keep the consistency of the original tissues. Visually, they were indistinguishable from the rock. Some of the chemical properties remained the same, but the tissue was unrecognizable as tissue.


Some microorganisms digest their food externally. They emit chemicals that break down proteins and other molecules. This causes much of the decay seen in dead organisms. However, these microorganisms can live only under certain conditions.

Microorganisms need certain things to live. All microorganisms need water. If the body is dried out rapidly and stays dry, then some of the molecules can last forever. Egyptian mummies are the most famous case of bodies preserved by dessication. The most active microorganisms need oxygen to live. Therefore, isolating a body from oxygen slows down decay a long while even while the body is immersed in water. The bodies found in peat bogs are a famous example of preservation by anaerobic conditions.

There is no scientific evidence that organic molecules eventually break down without microorganisms. As far as has been established so far, most molecules in a dry anaerobic environment will last forever.

Most bodies are exposed to living microorganisms after death. Usually, the bodies are exposed to both water and oxygen sometime after death. The water contains microorganisms that eat up the soft tissues. However, this is not always the case.

Here are two articles on bodies that have been preserved under “natural conditions” for more than one thousand years. Although I have chosen examples of bodies “only” thousands of years, note that there is theoretical limit to how long these bodies could have lasted. The statement that body tissues can last “at most” a few thousand years is false.


http://en.wikipedia.org/wiki/Mummy
“Mummies that are formed as a result of naturally-occurring environmental conditions, such as extreme coldness (Ötzi the Iceman, the Ice Maiden, the Llullaillaco child mummies), acid (Tollund Man), salinity (Salt Man), or desiccating dryness (Tarim mummies), have been found all over the world. More than a thousand Iron Age corpses, so called bog bodies, have been found in bogs in northern Europe, such as the Yde Girl and the Lindow Man.[24] Natural mummification of other animal species also occurs; this is most common in species from shallow saline water environments, especially those with a body structure which is particularly favourable to this process, such as seahorses and starfish. Old mummies such as the dinosaurs Leonardo, Dakota, and the Trachodon mummy in America were very valuable discoveries.”

https://www.google.com/#hl=en&tbo=d&...w=1024&bih=605
“The bog bodies of Northern Europe are human cadavers who have been naturally mummified within the peat bogs found in various parts of the continent. Such bodies, sometimes known as bog people, are both geographically and chronologically widespread, having been dated to between 9000 BCE and the Second World War.[1] The only unifying factor of the bog bodies is that they have been found in peat and are partially preserved; the actual levels of preservation vary widely, from those which are perfectly preserved to those who have survived as nothing more than a skeleton.[2]
Unlike most ancient human remains, bog bodies have retained their skin and internal organs due to the unusual conditions of the surrounding area. These conditions include highly acidic water, low temperature, and a lack of oxygen, combining to preserve but severely tan their skin. Despite the fact that their skin is preserved, their bones are generally not, as the acid in the peat dissolves the calcium phosphate of bone.”




The scientific study of what happens to bodies after death is called taphonomy.
http://en.wikipedia.org/wiki/Taphonomy
“The taphonomic pathways involved in relatively inert substances such as calcite (and to a lesser extent bone) are relatively obvious, as such body parts are stable and change little through time. However, the preservation of "soft tissue" is more interesting, as it requires more peculiar conditions. While usually only biomineralised material survives fossilisation, the preservation of soft tissue is not as rare as sometimes thought.”
DrDu
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Nov30-12, 03:46 PM
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Quote Quote by Darwin123 View Post
The main reasons of tissues decay is because microorganism eat the molecules. If the soft tissue is isolated from microorganisms soon after death, then the molecules can live a long time.
Yes, but also take in mind that most cretaceous deposits have been buried some kilometers below surface at elevated temperatures. I don't think that organic molecules especially appreciate these conditions for millions of years.
Evo
#15
Nov30-12, 03:51 PM
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Darwin, this wasn't actual soft tissue as in a mummy.
Darwin123
#16
Dec1-12, 05:45 PM
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Quote Quote by Evo View Post
Darwin, this wasn't actual soft tissue as in a mummy.
I knew that. The organic molecules were embedded in a matrix of minerals. When they say that "collagen fibers" were preserved, they mean that polymer molecules were interspersed with mineral crystals. Therefore, the tissues were not totally preserved in the most general sense of the word. The consistency of the material was not "soft", let alone "tissue". However, some of the articles cited did literally claim that "soft tissue" was "preserved".

Their are two issues of fairness, here. To be fair with the authors of these articles, there is no formal definition of "preservation". They did not mean that the tissues retained the precise same chemistry and the precise same consistency as the living tissue. Most readers were knew to read the rest of the article in context. To be fair with the OP who read these articles, it was easy to make the mistake of thinking the tissues were perfectly preserved, molecule for molecule with no minerals interspersed.

The OP appears to be making the following error which I was trying to correct. The OP thinks that there is a definite lifetime to organic molecules past which they automatically decompose.

The OP is probably thinking of bodies buried in moist soil or left on the surface of wet soil. A body left on the surface of wet soil is usually torn to pieces in a few days by animals, including insects. The microorganisms devour the organic molecules. Bodies buried in wet soil under most conditions decay in a matter of months. Microorganisms digest the organic molecules leaving only bone. The OP is extrapolating decay of this nature to all dead organisms, at all times.

Organic molecules don't decompose on a fixed schedule. Organic molecules last until something happens to them. There is no expiration date on organic molecules isolated from microorganisms. However, I wanted to show an observable fact to demonstrate that organic molecules last a long time.

Natural mummies demonstrate the fallacy of the OP's thinking. The mummies described can be shown to be at least a few thousand years old. Some of the molecules making up their tissues have survived. The OP may claim that a thousand years isn't 80 MY. However, a thousand years isn't a couple of months.

The existence of natural mummies demonstrates that organic molecules don't have an expiration date. Collagen has lasted in some of these mummies more than 2000 years. Chemicals from surrounding water got into some of these "tissues".

Also note that cooked tissues can last longer than uncooked tissues. More on that later.


If they did, then it would make forensic science much easier. To determine the time of death, one could simply look at what proportion of molecules had decomposed.
Darwin123
#17
Dec1-12, 06:15 PM
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Quote Quote by DrDu View Post
Yes, but also take in mind that most cretaceous deposits have been buried some kilometers below surface at elevated temperatures. I don't think that organic molecules especially appreciate these conditions for millions of years.
Heat doesn’t always destroy organic molecules. In fact, it helps preserve the structure of organic molecules. For instance, heat can cause polymerization of organic molecules. Polymerized molecules are often much more stable then the smaller molecules that formed them. Heat also kills microorganism.

Sedimentary rock is not formed at high temperature. If sedimentary rock is exposed to high temperature, it can either melt or turn into metamorphic rock. However, heat is not necessary to form sedimentary rock. Usually, sedimentary rock is formed under high pressure. The pressure causes the grains of mineral to stick together. Sometimes, water contributes to the formation of sedimentary rock by dissolving minerals. Most fossils are found in sedimentary rock.

If the fossils were found in metamorphic rock or igneous rock, then I could be suspicious. These rocks require high temperature. I suspect that proteins would last only seconds in magma. However, very few fossils are found in metamorphic or igneous rock.

Fossils are found in sedimentary rock. Sedimentary rock is seldom heated more than a few hundred degrees. The main thing that sedimentary rock is exposed to is pressure. Pressure does not cause organic molecules to decay.

Under high heat, organic molecules can ligonize. That is, the oxygen and water can be driven off forming graphite and other carbonaceous polymers. This is how coal forms. However, the fossilized bones in these articles weren’t found in coal mines. They were found in shale and sandstone. The sediments in shale and sandstone were never placed in temperatures of thousands of degrees. If sandstone or shale was placed in temperatures of thousands of degrees, the silica would melt.

Heat is one reason that cooked food can last longer than uncooked food.

http://en.wikipedia.org/wiki/Food_preservation
“Food preservation is the process of treating and handling food to stop or slow down food spoilage, loss of quality, edibility or nutritional value and thus allow for longer food storage.
Preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), and other micro-organisms (although some methods work by introducing benign bacteria, or fungi to the food), as well as retarding the oxidation of fats which cause rancidity. Food preservation can also include processes which inhibit visual deterioration, such as the enzymatic browning reaction in apples after they are cut, which can occur during food preparation.

Many processes designed to preserve food will involve a number of food preservation methods. Preserving fruit by turning it into jam, for example, involves boiling (to reduce the fruit’s moisture content and to kill bacteria, yeasts, etc.), sugaring (to prevent their re-growth) and sealing within an airtight jar (to prevent recontamination). There are many traditional methods of preserving food that limit the energy inputs and reduce carbon footprint.”


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