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Are Fossil Shark Teeth Just Rocks?


Shaney777

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Hello, I have a few questions about fossil shark teeth--I am referring to the black teeth that can be found on Myrtle Beach, SC shores. Is there any original organic material left in the fossil tooth when it is found on the beach? I know that some educational websites use the terms permineralization and petrifaction interchangeably, but the latter seems to mean there is no organic material left, while the former appears to mean there are organic cell walls filled with minerals present. There seems to be a lot of confusion about these terms, even with information on URLs ending in ".edu". Can you all direct me to some objective information on this matter--a peer-reviewed article or something? The reason I ask is because I am going to look for shark teeth soon, but if there is no organic material present--if all I am finding are merely rocks--the fun will basically be taken out of the hobby. If you could get back with me in the next couple days, I would be delighted.

Respectfully,
Shane
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Hello, I have a few questions about fossil shark teeth--I am referring to the black teeth that can be found on Myrtle Beach, SC shores. Is there any original organic material left in the fossil tooth when it is found on the beach? I know that some educational websites use the terms permineralization and petrifaction interchangeably, but the latter seems to mean there is no organic material left, while the former appears to mean there are organic cell walls filled with minerals present. There seems to be a lot of confusion about these terms, even with information on URLs ending in ".edu". Can you all direct me to some objective information on this matter--a peer-reviewed article or something? The reason I ask is because I am going to look for shark teeth soon, but if there is no organic material present--if all I am finding are merely rocks--the fun will basically be taken out of the hobby. If you could get back with me in the next couple days, I would be delighted.

Respectfully,
Shane

Hello,

I am not sure why the fun would would be taken out if they are "rocks"--original material or not, you're still holding a remnant of an animal that lived millions of years ago :D

But, as tmaier said, it depends on the formation, age, and geology of the area whether a tooth is organic.

Reese

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This person has posted the same question in two forums groups

(edit: looks like this has been fixed now...)

And, yeah... why do you need the organics... are you planing on doing some cloning? :D

Fragments of DNA have been found in dinosaur bones, more than 70 million years old. Thus the movie "Jurassic Park".

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They are teeth that were used by a creature that lived many millions of years ago. That is pretty cool whether organic material is technically still there or not.

It is a neat way to experience some of the history of the planet. And the cells of that ancient shark are still there just filled in with minerals.

Somewhere, something incredible is waiting to be known.–Carl Sagan

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This person has posted the same question in two forums groups

(edit: looks like this has been fixed now...)

And, yeah... why do you need the organics... are you planing on doing some cloning? :D

Fragments of DNA have been found in dinosaur bones, more than 70 million years old. Thus the movie "Jurassic Park".

No. There was some DNA reported in 1994, but it turned out to be human contamination. A study in 2012 concluded that DNA would have completely degraded by 6.8 million years, though it is possible that this is incorrect due to the discovery of possible DNA remnants in Tyrannosaurus and Brachylophosaurus osteocytes, but sequence data is required to verify this. http://news.ncsu.edu/2012/10/tpschweitzer-bone/

Sequences of collagen and other proteins have been found in the same fossils as the osteocytes, though they have been controversial, their similarity to modern archosaurs above other animals seems to suggest authenticity. It would be possible to create a DNA sequence that codes for that protein sequence, but since proteins are regulated by DNA sequences to make appearances and functions and stuff, this would be useless for anything other than maybe adding a sense of "authenticity" to something like Jack Horner's hypothetical "chickenosaurus", which has a lot more promise.

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I must say this is one of the more unusual questions that I have read on here. I not sure why organic material is the determining factor that you are looking for to make it worth your time to find fossilized sharks teeth. Does that mean you would also pass up on finding a dinosaur bone or tooth because it is also fossilized? Anyway, here are some of the "rocks" that I have found and proudly display in my office.

post-12849-0-64280900-1410239424_thumb.jpg

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Did anyone tell the Field Museum of Chicago that they paid $8.3 M for pile of rocks in their T rex Sue?

I love my rocky shark teeth and have never thought of them in that fashion. To me they're great predators of an older ancient ocean that I love to hunt and be the first person to ever see and touch their teeth.

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These teeth certainly had organic origins; irregardless of their current composition, they are fossils.

If this doesn't float your boat, maybe fossil collecting is just not your thing?

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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You should research the definition of fossilized.....and then leave those 'just rocks' alone for those that appreciate what they are.

...I'm back.

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I think we have had discussions before about all the ways remains can be fossilized. There are a dozen or more different types of preservation but I've wondered about teeth myself because so often people mention the lack of enamel on items posted as possible teeth. The surface past the root is always very shiny on all the teeth I find and I have wondered if it's the original enamel, or is it replaced with minerals that take on the sheen because of the original texture? Or does it vary as tmaier said and if so, how do you tell which?

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This person has posted the same question in two forums groups

(edit: looks like this has been fixed now...)

And, yeah... why do you need the organics... are you planing on doing some cloning? :D

Fragments of DNA have been found in dinosaur bones, more than 70 million years old. Thus the movie "Jurassic Park".

A few more corrections needed here. The “Jurassic Park” (mostly Cretaceous actually) movie relies on DNA extracted from mosquitoes (ie blood-feeders) preserved in amber and not from dinosaur fossils. The incomplete sections were filled with DNA from modern frogs. Studies at Manchester University in 2013 have suggested that this is an unpromising route for DNA recovery. A number of experts were tasked with recovering DNA from an array of insect-included copals (young ambers) between 60-10,600 years old but almost nothing was recovered by any of them.

Woodward et al. published claimed mitochondrial cytochrome b sequences that had been extracted from dinosaur bones dating to over 80 million years old in 1994 to international acclaim but we have learnt to be cautious about such claims because of the difficulties presented by subsequent contamination. As ‘Carcharodontosaurus’ says, at least five independent laboratories reviewing the results have determined the DNA to be almost certainly derived from recent human Y-chromosome contamination (Hedges et al. 1995; Collura and Stewart 1995).

Researchers at Beijing university in China have also published claimed dinosaur DNA sequences using flocculent inclusions from Cretaceous egg fossils (An et al. 1995; Li et al. 1995). The findings were (oddly) published in a non-mainstream journal with inadequate peer-review and have also been treated with scepticism. Independent analysis of the published sequences has shown that they best match some fungi and flowering plants – notably the symbiotic fungi found on some leaf-cutter ants, lichen-forming algae, thale cress, eggplant and potato (Wang, Yan & Jin 1997). This is likely modern contamination again.

As far as I know, the oldest published sequence comes from a 560–780 thousand year old horse, based on DNA material extracted from a leg bone preserved in the Yukon permafrost in Canada (Hayden 2013). Without the benefit of permafrost, the oldest published sequence is probably from a cave bear in Germany, dated to more than 300,000 years old (Dabney et al. 2013)

I would also think that the typical environments and modes of preservation for shark teeth are not likely to be conducive to the long-term preservation of genetic material in the way that cave (or desert) mummification or low temperature permafrost works. Freezing studies also suggest that preservation is not just a low temperature effect… it benefits hugely from a relatively stable low temperature with little fluctuation.

Roger

I keep six honest serving-men (they taught me all I knew);Their names are What and Why and When and How and Where and Who [Rudyard Kipling]

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A few more corrections needed here. The “Jurassic Park” (mostly Cretaceous actually) movie relies on DNA extracted from mosquitoes (ie blood-feeders) preserved in amber and not from dinosaur fossils. The incomplete sections were filled with DNA from modern frogs. Studies at Manchester University in 2013 have suggested that this is an unpromising route for DNA recovery. A number of experts were tasked with recovering DNA from an array of insect-included copals (young ambers) between 60-10,600 years old but almost nothing was recovered by any of them.

Woodward et al. published claimed mitochondrial cytochrome b sequences that had been extracted from dinosaur bones dating to over 80 million years old in 1994 to international acclaim but we have learnt to be cautious about such claims because of the difficulties presented by subsequent contamination. As ‘Carcharodontosaurus’ says, at least five independent laboratories reviewing the results have determined the DNA to be almost certainly derived from recent human Y-chromosome contamination (Hedges et al. 1995; Collura and Stewart 1995).

Researchers at Beijing university in China have also published claimed dinosaur DNA sequences using flocculent inclusions from Cretaceous egg fossils (An et al. 1995; Li et al. 1995). The findings were (oddly) published in a non-mainstream journal with inadequate peer-review and have also been treated with scepticism. Independent analysis of the published sequences has shown that they best match some fungi and flowering plants – notably the symbiotic fungi found on some leaf-cutter ants, lichen-forming algae, thale cress, eggplant and potato (Wang, Yan & Jin 1997). This is likely modern contamination again.

As far as I know, the oldest published sequence comes from a 560–780 thousand year old horse, based on DNA material extracted from a leg bone preserved in the Yukon permafrost in Canada (Hayden 2013). Without the benefit of permafrost, the oldest published sequence is probably from a cave bear in Germany, dated to more than 300,000 years old (Dabney et al. 2013)

I would also think that the typical environments and modes of preservation for shark teeth are not likely to be conducive to the long-term preservation of genetic material in the way that cave (or desert) mummification or low temperature permafrost works. Freezing studies also suggest that preservation is not just a low temperature effect… it benefits hugely from a relatively stable low temperature with little fluctuation.

Painshill pretty much nailed it. If I recall correctly, DNA degrades very fast in water. And any "resurrected dinosaur", due to a lack of original DNA, would have to be made from a synthetic genome. This would mean that a recreated T. rex, for example, would be to its original version what a thylacine is to a wolf. In other words, not a true tyrannosaur.

You could create something very similar to megalodon by enlarging a great white through modifying its genome, but due to a general lack of successes in keeping great whites in captivity, their little-known breeding cycle, and many other factors mean that this would be far more trouble than it would be worth.

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I was watching a PBS special about great whites that inhabit the New Jersey coast during summer. On their migration south in the fall, the females head for a very deep part of the Atlantic, while the males head for Florida. Then the females come back from the depths and join the males around Georgia and north Florida coast.

In seems a nursery might be in the depths of the Atlantic.

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I feel that my topic offended some of you. I wasn't try to do that! :(

I'm just saying that if a fossil shark tooth has never been in a shark's mouth, I don't see how it could even be called a tooth. If every single part of the original tooth has been replaced by rock, it can no longer be called a tooth. And it being a real tooth that was used to kill prey was the main special thing about them for me...

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it being a real tooth that was used to kill prey was the main special thing about them for me...

You are a very special person. :D

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I'm just saying that if a fossil shark tooth has never been in a shark's mouth, I don't see how it could even be called a tooth. ..

Wow that's an interesting comment. So if a fossil tooth has never been in a sharks mouth who made it? Do you understand the principles of fossilization?

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These teeth were absolutely once in the mouths of living, eating sharks (long, long ago). Many were probably shed during the shark's lifetime, in the normal (for sharks) course of replacement; being durable, they were preserved in the sea floor sediment.

"There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant

“Try to learn something about everything and everything about something.” - Thomas Henry Huxley

>Paleontology is an evolving science.

>May your wonders never cease!

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Any time you want to pass by a nice tooth just because it hasn't directly come from the sharks mouth (give or take several million years) you just give me a call and I will be happy to get that nasty ol' rock out of your way.

 

 

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I have tests I can do to verify that there actually are some organics left, and the tooth was actually used to kill large animals. But... it involves lasers, big, powerful, dangerous lasers... and mutated bass.

you would have to send me the tooth.

post-16101-0-46977900-1410298816.jpeg

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I think what he is saying is that everything that made it a tooth has been replaced with minerals into something else. While I can see it from this point of view I still have my breath taken away when I pick up a tooth that hasn't been handled in millions of years and hold it in my hand.

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:wacko:

I've wondered about teeth myself because so often people mention the lack of enamel on items posted as possible teeth. The surface past the root is always very shiny on all the teeth I find and I have wondered if it's the original enamel, or is it replaced with minerals that take on the sheen because of the original texture? Or does it vary as tmaier said and if so, how do you tell which?

I never quoted myself before but I'm not sure if my question got answered...or if it even makes sense :wacko:

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:wacko:

I never quoted myself before but I'm not sure if my question got answered...or if it even makes sense :wacko:

Yes, it makes perfect sense Bob. It’s another of those “difficult to answer” questions, but I’ll have a go.

The enamel “layer” of shark teeth should more properly be termed “enameloid” from a histological point of view. It actually consists of four zones: a juxta-laminar zone containing newly polymerized mineralizing fibrils (tubules); a pre-enamel zone assembled from matrix constituents; palisadal zones of mineralizing fibrils (tubules); and interpalisadal zones containing granular amorphous matrix, fine unit fibrils, and giant cross-banded fibres.

Considering the layer as a collective, you could see it as mostly composed of hydroxyapatite (a form of calcium phosphate) crystals formed by secretion and nucleation onto a preformed protein matrix that consists of several hundred different proteins, of which collagens represent the largest group. The matrix accumulates on an emerging tooth at the tip and then extends over the whole crown. Soon after the matrix appears, it begins to calcify by deposition of hydroxyapatite crystallites.

The proteins are easily degraded and are the first to disappear after death. Fragmented amino acid derivatives and polymerised byproducts from them might survive the fossilization process (very rarely) but not the proteins themselves. So, you could say that since the proteins have gone, then you no longer have “enamel” in the fossil. The zones will be lost at different rates (assuming they preserved in the first place) and which zone is exposed will largely determine the extent to which the surface looks "enamel-like", together with colouration effects from mineral-staining.

As for the hydroxyapatite, during the early stages of fossilization, it is sometimes the case that new crystalline material grows from the original hydroxyapatite. These secondary crystals are very much larger than those that would have originally been present, but much fewer in number. They’re probably the result of the original hydroxyapatite being re-solubilized under pressure and being re-deposited in the spaces left by the decayed proteins.

Typically, what you can see under the microscope is a more pronounced crystallinity than was present in the original tooth and a mixture of crystal sizes that could loosely be divided into “tiny” and “large”. Interestingly, the “in-vivo” alignment of the crystals (the long axis) often persists in the fossil. A major proportion of the hydroxyapatite is probably original material in many fossils but it’s arguable whether it should be termed “enamel” (probably not).

One other interesting note is that hydroxyapatite in fossil teeth (and more especially in fossil bones) frequently has elevated levels of fluorine, which substitutes for the hydroxide groups to create fluoroapatite. The crystal size is usually unchanged in those circumstances. Quite why this happens is not well understood, but the levels are well above those that could have originally been present. There is evidence to suggest that this happens very early on in the fossilization process and may be an important step in stabilizing the mineral, such that it determines the subsequent degree of preservation of detail at a micro-level.

The oft-quoted “molecule by molecule” replacement to describe the mineralization process for fossilization is 100-year old textbook stuff and a long way from what we know today about how most mineralized fossils are formed. It’s a useful simplification to help people get their minds round what happens, but no more than that.

Roger

I keep six honest serving-men (they taught me all I knew);Their names are What and Why and When and How and Where and Who [Rudyard Kipling]

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