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Definition of a Fossil


I_gotta_rock

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So, here's one bound to start arguments, but how would you define "Fossil?" I was looking at a children's book the other day, and it was trying to differentiate a modern sea shell sitting on the beach with a fossil. It said that a seashell was not a fossil because it was not embedded in rock. By that definition, the vast majority of what I have in my collection is not a fossil because it was never embedded in rock. In Calvert Cliffs (Maryland), Big Brook (NJ), The C and D Canal (Delaware), Peace River (Florida) and other locales, the matrix is packed sand if not outright loose sediment. So, by this book, they are not fossils.

 

Another definition I saw said that a fossil had to be in stone or replaced by another mineral. I'm not 100% sure, but aren't  Pliocene fossils frequently not replaced by anything, just a bit leached and/or filled in from the surrounding matrix? Maybe I'm wrong on that point.

 

A third one I saw said that it had to be at least 10,000 years old. I will challenge this one with the case of Saratoga, NY. The springs there are so heavy in minerals that they create STONE casts of the leaves that fall on the-ever-growing mineral domes in  a matter of days. A cast is thick enough to peel off the leaf in a few weeks. The domes are riddled with hundreds and thousands of leaf impressions. If this is not a fossil now, what would make it a fossil later?

I refuse to give up my childish wonder at the world.

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I say fossil is really a label given by humans to biological remains and traces (and sometimes trace of other processes), that normally means:

A) has been mineralized, and is/ or is

b ) is more than 8,000 years old (I'm starting at the beginnings of bog wood turning to lignite 

Anything under this that has not been mineralized may be described as a subfossil and those from the anthropocene do not yet count.

as for Saratoga, this is similar to a Petrifying well and I would not count it as a fossil till it's a few (8) thousand years old. 

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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In my definition, a fossil defines as any impression or remains of a once-living organism that has been preserved in a petrified form. Petrified as in that there is no more "true" organic material, but preserved forms of it that has been replaced by minerals (The mineral part doesn't mean that all fossils are actually supposed to be crystals, as the minerals will still take on the exact same shape of the once organic material: think of it as the bones being "medusafied") And the claim that anything not embedded in rock is 100% not a fossil is farfetched, sure a lot of fossils usually are found embedded in matrix (its possible that they meant rock as in any form of natural matrix like sand or dirt), but remember that erosion is a thing. Fossils can be loosened from matrix, carried along rivers, then deposited in the riverbed, its possible that smaller fossils could serve as river pebbles too.

 

Pliocene fossils not being permineralized is actually false (with a few exceptions), because it has been theorized that it would take at least 10,000 years to fully fossilize organic material, and the pliocene epoch ends i think 2.6 million years ago, which also means that pleistocene fossils are most likely to be fully fossilized too. Its only during the holocene when fossilization doesn't finish, which also explains why the next book says that a fossil must be at least 10,00 years old to be one. However, I still would consider material that is majority fossilized as still a fossil.

 

About the well spring scenario, it also possible that a fossil also defines as what i said before, but the fossilization must take over long periods of time the traditional way, so probably a leaf that fell in the spring could be considered a fossil after a few thousand years, despite being permineralized after only a few weeks.

If you're a fossil nut from Palos Verdes, San Pedro, Redondo Beach, or Torrance, feel free to shoot me a PM!

 

 

Mosasaurus_hoffmannii_skull_schematic.png

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1 minute ago, Macrophyseter said:

In my definition, a fossil defines as any impression or remains of a once-living organism that has been preserved in a petrified form. Petrified as in that there is no more "true" organic material, but preserved forms of it that has been replaced by minerals (The mineral part doesn't mean that all fossils are actually supposed to be crystals, as the minerals will still take on the exact same shape of the once organic material: think of it as the bones being "medusafied") And the claim that anything not embedded in rock is 100% not a fossil is farfetched, sure a lot of fossils usually are found embedded in matrix (its possible that they meant rock as in any form of natural matrix like sand or dirt), but remember that erosion is a thing. Fossils can be loosened from matrix, carried along rivers, then deposited in the riverbed, its possible that smaller fossils could serve as river pebbles too.

 

Pliocene fossils not being permineralized is actually false, because it has been theorized that it would take at least 10,000 years to fully fossilize organic material, and the pliocene epoch ends i think 2.6 million years ago, which also means that pleistocene fossils are most likely to be fully fossilized too. Its only during the holocene when fossilization doesn't finish, which also explains why the next book says that a fossil must be at least 10,00 years old to be one. However, I still would consider material that is majority fossilized as still a fossil.

Check out a shell found by @Rocky Stoner from the Devonian epoch, completely intact and unmineralized (although crystals are grownping out of it) as well as mammoth mummies and hair. DNA has been found in Miocene plants (as well as lipids I believe), as well as fragmented DNA in amber, which coats but does not mineralized. Shasta ground sloth dung has been preserved in caves without mineralization (well until one idiot lit a cigarette, methane combusted) and birds on many islands (most famously the dodo) are thousands of years old and unfossilized, same with Moa tissue. Homo floresiensis was older than ten thousand years and its bone was unfossilized. These are a few examples...

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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oh, okay  (i dont know what else to say)

If you're a fossil nut from Palos Verdes, San Pedro, Redondo Beach, or Torrance, feel free to shoot me a PM!

 

 

Mosasaurus_hoffmannii_skull_schematic.png

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2 minutes ago, Macrophyseter said:

oh, okay  (i dont know what else to say)

Its an amazing fossil world out there, with every type of preservation possible. Fossil is a human term used to describe a plethora of objects, unfortunately nature does not listen to our definitions. This is why it's hard to have one exact definition, because it's ever changing. Would you have said that maybe ten years ago, it wouldn't be challenged. In the next ten, who knows? Hopefully I will have a pet diprododon, but that's just an aspiration....

if theres one thing this forum has taught me, is that I'm not wrong a small percentage of the time, I'm right a small percentage of the time, but I'm okay with this because I learn more than all you right people out there. Cheers!

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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1 hour ago, WhodamanHD said:

Its an amazing fossil world out there, with every type of preservation possible. Fossil is a human term used to describe a plethora of objects, unfortunately nature does not listen to our definitions. This is why it's hard to have one exact definition, because it's ever changing. Would you have said that maybe ten years ago, it wouldn't be challenged. In the next ten, who knows? Hopefully I will have a pet diprododon, but that's just an aspiration....

if theres one thing this forum has taught me, is that I'm not wrong a small percentage of the time, I'm right a small percentage of the time, but I'm okay with this because I learn more than all you right people out there. Cheers!

Yep, and I posted this for just such a learning exercise.

I refuse to give up my childish wonder at the world.

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Any remains of a formerly living organism from a earlier geologic age, ie... remains,imprints,casts and molds, tracks,traces.

"Absence of evidence is not evidence of absence"_ Carl Sagen

No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go.

" I think, therefore I collect fossils." _ Me

"When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes

"can't we all just get along?" Jack Nicholson from Mars Attacks

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"any single (or collection of single)physical or chemical piece(s) of evidence that proves the former existence of the currently accepted definition of "life"."?????

This strangely aberrant definition might be necessary to include chemofossils.

I decided on this definition because i wanted to exclude e.g. the microbial fractionation/uptake & redistribution of several elements  /compounds from the definiton.

A delta 34S signature is NOT a fossil

 

 

 

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1 minute ago, doushantuo said:

"any single (or collection of single)physical or chemical piece(s) of evidence that proves the former existence of the currently accepted definition of "life"."?????

This strangely aberrant definition is necessary to include chemofossils.

 

Are mud cracks and raindrops ever counted as fossils?

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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No.

You might call it fossil evidence that there was such a thing as the hydrological cycle in the past

 

 

 

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Just now, WhodamanHD said:

Are mud cracks and raindrops ever counted as fossils?

Probably not, unless rain is considered to be covered under the "accepted definition of 'life'?"

I refuse to give up my childish wonder at the world.

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The lines are very blurry to me, I say we just call everything rocks and be happy if they have funny shapes in them.:P

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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BTW, the proper term is "semantics".:D

Yours truly always looks belatedly at the tags:D

annoying bad habit.

Does anyone share it?

 

 

 

 

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7 minutes ago, doushantuo said:

Yours truly always looks belatedly at the tags:D

annoying bad habit.

Does anyone share it?

What tags?:P

 

Darwin said: " Man sprang from monkeys."

Will Rogers said: " Some of them didn't spring far enough."

 

My Fossil collection - My Mineral collection

My favorite thread on TFF.

 

 

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It seems a lot of members remark upon the fact that tags aren't visible.

the tags are "fossil","definition","symantics"

 

 

 

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1 hour ago, doushantuo said:

BTW, the proper term is "semantics".:D

Yours truly always looks belatedly at the tags:D

annoying bad habit.

Does anyone share it?

 

I too have forgotten to look at tags before asking a question. Best practices dictate that all important information should be in the body of the post. Imagine writting a few paragraphs about President Lincoln and not mentioning 'Lincoln' in the body of the post because 'Lincoln' was a tag. A tag should be a reminder of an important term in the body of a post. Now I need to always practice what I preach.

My goal is to leave no stone or fossil unturned.   

See my Arizona Paleontology Guide    link  The best single resource for Arizona paleontology anywhere.       

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Interesting question....

I think like all words the term fossil has a meaning that may have evolved slightly with time. If you go back to the roots of the word fossil:

Latin: fossilis "dug up/out"

 

So could a fossil be anything dug up out of the ground? Surely minerals wouldn't be fossils? 

 

Then look at the English derivation from fossilis. The Oxford dictionary is similar to many definitions:

 

"The remains or impression of a prehistoric plant or animal embedded in rock and preserved in petrified form"

 

Does a fossil need to be petrified or mineralized to be a fossil? What about buried in rock? What about mammoths preserved in permafrost? They are not mineralized or buried in rock.

I saw a possum embedded in asphalt once presented as a fossil.

 

I think there is a bit of fluidity here and there is not a universally accepted definition. There are grey areas. There are things that definitely aren't fossils, like a recently dead plant or animal, and things that definitely are - such as a dinosaur skeleton. But no solid line seperating them.

 

I know that for Quaternary work (the last few million years) the term sub-fossil is often used for remains buried in sediments but not mineralized.

 

 

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12 hours ago, WhodamanHD said:

Its an amazing fossil world out there, with every type of preservation possible. Fossil is a human term used to describe a plethora of objects, unfortunately nature does not listen to our definitions. This is why it's hard to have one exact definition, because it's ever changing. Would you have said that maybe ten years ago, it wouldn't be challenged. In the next ten, who knows? Hopefully I will have a pet diprododon, but that's just an aspiration....

if theres one thing this forum has taught me, is that I'm not wrong a small percentage of the time, I'm right a small percentage of the time, but I'm okay with this because I learn more than all you right people out there. Cheers!

Have to ask-why Diprotodon? We find 'em :D

 

"Let us therefore follow after the things which make for peace, and things wherewith one may edify another."
-Romans 14:19

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1 hour ago, Jesuslover340 said:

Have to ask-why Diprotodon? We find 'em :D

 

Who wouldn't want a large wombat as a pet? You could ride upon it, mow your lawn with it, and fertilize your crops with it! I could start a farm, I bet diprotodon cheese would be good...

The cute creature would be a welcome addition to my family, you just gotta find some viable DNA, then I can start my diprotodon farm!:P

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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3 hours ago, Doctor Mud said:

 

Interesting question....

I think like all words the term fossil has a meaning that may have evolved slightly with time. If you go back to the roots of the word fossil:

Latin: fossilis "dug up/out"

 

So could a fossil be anything dug up out of the ground? Surely minerals wouldn't be fossils? 

 

Then look at the English derivation from fossilis. The Oxford dictionary is similar to many definitions:

 

"The remains or impression of a prehistoric plant or animal embedded in rock and preserved in petrified form"

 

Does a fossil need to be petrified or mineralized to be a fossil? What about buried in rock? What about mammoths preserved in permafrost? They are not mineralized or buried in rock.

I saw a possum embedded in asphalt once presented as a fossil.

 

I think there is a bit of fluidity here and there is not a universally accepted definition. There are grey areas. There are things that definitely aren't fossils, like a recently dead plant or animal, and things that definitely are - such as a dinosaur skeleton. But no solid line seperating them.

 

I know that for Quaternary work (the last few million years) the term sub-fossil is often used for remains buried in sediments but not mineralized.

 

 

Not definitive answers, just what I think:

1) of course a fossil isn't anything dug out of the ground, if it was it would be a lot easier to find them

2) doesn't have to be petrified, some examples of this are in one of my comments above.

3) calvert cliffs has got fossils not buried in rocks, for they have eroded out. Plus, unconsolidated material can have fossils.

 

like you said, the term 'fossil' really doesn't have one definition, because it's really hard to draw lines. Scientists still struggle with an exact definition for life, so that messes up the life part. Sometimes subfossil refers to a fossil of any age that has not completed mineralization, but these make it hard as well. Intresting subject.

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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From a historical standpoint the definition has changed as science has needed more specific terms. You can find old references that refer to what we call artifacts now as fossils because of the Latin use as Dr. Mud mentioned and very old dictionaries will say it's anything old dug up out of the ground. The crossover between older archeology and paleontology has yielded terms like paleoarcheology and archeopaleontology which I won't try to justify or define. I keep seeing 10,000 years as a line to draw between them, probably because of the extinctions around that time and it's just a nice round number. Of course today the definitions Herb and others gave are what we use. Luckily for the purposes of explaining an item it isn't really a scientific term at all. You won't see it in a peer reviewed paper written about a specific fossil or group of fossils because the reader wants to see a specimen described in more specific terms. Instead of "fossilized" you will see mineralized, permineralized, carbonized, etc. and to describe a fossil it's an internal mold, resin inclusion, desiccated, bioimuration and so on. Depending on how they divide up general preservation methods there are a dozen or so different terms that tell a lot more about a specimen than to just say "fossil".

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