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Would an ancient (greater than 10,000 years old) human artifact (such as a tool) be considered a fossil?

Recently, a group of paleontologists were having a discussion regarding fossil shells after a woman produced one for identification. Discussion turned to the difference between a shell and a fossil shell (that being a shell which has permineralized). There was debate as to whether or not there are any shells that are older than any fossil shells in the general paleo record. One of the paleontologists knows a shell expert and she reported back that the oldest known shell is approximately 18,000 years old and that all shells older than that have permineralized. However, some found this difficult to believe, as shell material, being mostly calcium carbonate, should be able to survive for very long periods in non-acidic deposition environments. Can anyone confirm this? Thanks!

Hi all, I recently got into a discussion on the Dutch fossil forum about the definition of the term "carina", which my conversation partner equated to "the cutting edge of a tooth". They then further went on to claim crocodiles don't have carinae but rather apicobasal ridges that span the length of the tooth crown. Now I've used the term lots over the years and know @Jesuslover340 has also used carinae in the context of crocodile teeth. But as I can't find a singular definition of the term as pertains to teeth online, I was wondering how the term is officially defined - whether it might be possible that I may have been using it wrongly and under the wrong assumptions. So, basically: What are carinae? Are they the cutting edges of a tooth, or do they include the apicobasal ridges that are commonly found on the mesial or dorsal end of reptile teeth? Are carinae necessarily serrated? Is use of the term "carina" taxonomically restricted? Does the term apply to crocodiles, for example? I possible, I would like to try and get at an academically recognized definition of the term. Or, failing that, get insight into the academic discussion as to its meaning.

This is probably a really "beginner" question... but I keep seeing references to Tractor Ammonites. What does the "tractor" refer to? Because they "pulled" things? I'm sort of embarrassed to ask, but I really want to know! Dpaul7

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?