A layman's question

I am just wondering how long it takes for things to rot on the sea floor. A fish for example - I heard from somewhere they go quickly ?If they rot quickly how do they fossilize?
Do fossils take a long time? - I'm puzzled as to why they fossilize? - Can someone in the 'know' correct my thinking.

Try a google on that word.Here is one site you will find.
http://paleo.cortland.edu/...al/Taphonomy&Pres/taphonomy.htmThis is the study of how fossils form.I am not an expert but I'll try to summarize.For a fossil to form, generally something does have to happen fast. That is the dead organism must be protected pretty quickly. A body left out gets scavanged and abraded pretty quickly. It will be scattered and probably chewed to scraps.Then it may take a long time to "fossilize" depending on what that means. If it is preserved by mumification or being trapped in amber it happens quickly. If it is a replacement of bone with mineral it will take much longer, but I don't know how long. Have you noticed that most fossils are of bones? Soft parts are very, very, very rarely preserved in any way.

I agree Ned, infact if the fossils happen fast does that mean the rocks do not have to have taken millions of years or am I thinking too simplistically? - does it at least mean that fossilization happens quickly?

The seabed is full of scavengers and a carcass won't be lying there with flesh on for long. The BBC's Abyss 2003 live event a couple of months ago showed in real time it took a couple of hours for sharks, crabs and other aquatic species to take care of a dead tuna.As for fossilisation, no idea, but given the amount of soft sediment down there, it'd be a good place to get burried at least and rubbish is always falling down there.

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I agree Ned, infact if the fossils happen fast does that mean the rocks do not have to have taken millions of years or am I thinking too simplistically? - does it at least mean that fossilization happens quickly?

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You're misunderstanding. The fossilization doesn't occur quickly: The species has to be *protected* quickly for it to fossilize. For it to actually fossilize, minerals have to leech into it and replace the bone, which is a very, very slow process (the main reason why the organism must be protected quickly)------------------
"Illuminant light,
illuminate me."

Just one minor correction - I hope you don't mind.

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hen it may take a long time to "fossilize" depending on what that means. If it is preserved by mumification or being trapped in amber it happens quickly. If it is a replacement of bone with mineral it will take much longer, but I don't know how long.

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Amber formation is actually quite slow. Resin turns to copal in a couple thousand years, but copal takes millions of years to turn to amber. Resin is relatively unbonded. Copal forms when the molecules in the resin begin to bond with each other. Amber forms when the volatile oils, such as turpentines, seep out of the copal; this cannot occur quickly. The whole process must occur in an anerobic environment (you'll notice that old amber jewelry often shows signs of cracking and other damage to its surface).------------------
"Illuminant light,
illuminate me."

The Green River Formation is probably THE famous fossil fish location. I believe the deposits of the formation are from a lake.I plead "not an expert" also, but I suspect in the case of the Green River Formation lake, the water layer at the bottom might have been quite toxic, which helped preserve the fish remains.Try Googling "Green River Formation", maybe also with a + fish.MoosePS - Registration as a forum member in encouraged.

Lets take Any of various usually burrowing marine and freshwater bivalve mollusks of the class Pelecypoda, including members of the genera Venus and Mya, many of which are edible.-Lol, they are found closed. Impress me and tell me why? Oh? - no, I think it does make sense if you take your evo shades off![This message has been edited by mike the wiz, 12-16-2003]

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Impress me and tell me why?

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The all-powerful magic of God.What? Don't like that answer? ok.... (heh, I get to provoke you, too ).There are three main lifestyles mature bivalves can have in present-day earth: buried in the sand, living on sediment on the surface, and attached to hard objects (such as coral or rocks) (some even *burrow into* these surfaces before attaching, such as shipworm). The first, and to a lesser extent the last, will fossilize closed. Only the middle type is unlikely to fossilize closed.------------------
"Illuminant light,
illuminate me."[This message has been edited by Rei, 12-16-2003]

Why? Just remember YOU mentioned God first

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Only the middle type is unlikely to fossilize closed.

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Why?

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If you're buried in sediment that you've dug down into, your shell can't open up after you die. If your shell is attached on both sides to rock or coral, it can't open up either. It can only open up if you're eaten (i.e., unlikely to fossilize anyway, because you'll probably be broken to pieces in the process) or if you weren't buried or attached to anything to begin with (such as scallops) - the middle category.------------------
"Illuminant light,
illuminate me."

Good pupil, sorry point but how many are found helter shelter? - Are they found fossilized open

Mike, do you have a reading comprehension problem?The protection has to happen pretty quickly if we want a "good" fossil. That does not say anything about rocks forming fast. Burying it quickly in mud, sand or ash is a good way to do that. Getting it into a low oxygen environment (at the bottom of some lakes) might do too. This can happen in seconds or hours.The change into what we call a fossil is something else. Exceptions are as noted; amber for example. Even there the change of sap into amber is a slower process. Again, I don't know how long that is.

Thank you, Rei, I did speak out of turn there not knowing about amber formation. And sorry about not reading ahead and posting a duplicate of what had already been posted.------------------
Common sense isn't[This message has been edited by NosyNed, 12-16-2003]

I do have problems sometimes. I am teasing you to an extent- as you already know about my evil creo agenda. What prevents fast fossilization?
- If fossils are in the rocks for example - if the fossil happened fast why didn't the rock?