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Fossil Claw

Blurred line between fossil and modern

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Fossil Claw

I picked up this Wild boar (Sus scrofa) jaw section from Florida recently. While it not recognized in the Florida fossil record due to the boar being an introduced species in the past 600 years or so years. This  piece has heavy patina, and is mineralized but is too young to be a fossil as  it is thought to be a peice that is 400-500 years old.

 

I have Mastodon and cave bear material that are older and far less mineralized.

 

Other than using the rough date of 11k years ago, how else do I explain why a younger less mineralized peice is not a fossil while an older less mineralized peice is a fossil?

Thoughts?

IMG_20190118_134315.jpg

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Jesuslover340

A fossil is generally considered something over 10,000 years old and exhibits mineralization, at least to some extent (I think this is the general definition most people give to 'fossil', but it really has no specific definition concerning issues such as this.) So I guess you'd say that, while mineralized, it doesn't really fit the criteria for age.

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Jesuslover340

Mineralization itself would be subjective per the environment and of course, the time given for the process to occur. So though a fossil is often mineralized, perhaps the age criteria is what is best to go by, as it is not subject to the conditions of the environment.

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Jesuslover340

However, the issue as to the definition of what a 'fossil' is becomes more difficult to place when, say, you have a specimen of an animal known to have existed over 10, 000 years ago, is mineralized, but comes from an animal that still exists presently (take bison, for example). Generally, you'd consider such a specimen a fossil even if it's actually under 10,000 years (though you'd only really know by testing). Or because of the mineralization of the specimen, it would  be assumed to be over 10,000 years for the general fossil collection. It's in situations such as these where what makes a fossil a fossil becomes a bit arbitrary and unclear.

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Jesuslover340

To be fair, though, 'fossil' is still an evolving definition of certain specimens dug from the ground. For example, 'fossil' used to refer to anything dug from the ground, if I recall correctly. 

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FranzBernhard

:headscratch::doh!:

 

From Wikipedia:

 

Subfossil:

"For remains such as molluscan seashells, which frequently do not change their chemical composition over geological time, and may occasionally even retain such features as the original color markings for millions of years, the label "subfossil" is applied to shells that are understood to be thousands of years old, but are of Holocene age, and therefore are not old enough to be from the Pleistocene epoch."

 

Holocene:

"The Holocene is the current geological epoch. It began approximately 11,650 cal years before present, after the last glacial period, which concluded with the Holocene glacial retreat."

 

Compare with:

Fossil:

"Specimens are usually considered to be fossils if they are over 10,000 years old."

 

:doh!::headscratch:

 

Franz Bernhard

 

 

 

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JohnBrewer

I was just gonna mention Holocene...

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steelhead9

What makes you believe the jaw is mineralized? As little as several hundred years in a tanin rich river could account for the dark coloration. To my knowledge, mineralization is not relevant to defining a fossil. The only requirement is that it be from before the Holocene. A good example would be Pleistocene fossils from LaBrea tar pits or the Siberian permafrost. Remains of these animals have no mineralization but are correctly viewed as fossils. 

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Uncle Siphuncle

Hey Dom can we get a clear occlusal view of the teeth?  

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UtahFossilHunter
2 hours ago, steelhead9 said:

 The only requirement is that it be from before the Holocene. 

Even then how much of a difference is there between a specimen of a species 50 years before the Holocene boundary and a specimen of the same species 50 years after. They could even be parent and offspring at that timeline. One would be a fossil and the other would not with that definition.

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steelhead9

That is true and without carbon dating you couldn’t tell. It is very hard to make an exact determination with species that still exist and are not genetically different between now and then. The instances of this actually happening are probably scientifically insignificant. Despite the potential for this grey area, the technical definition of a fossil is still a plant or animal that lived before the current time period. 

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Peat Burns

Evidence of past life preserved in a geologic context.

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