This is a series of quick question and answers we get at our museum all the time. It is not intended for the scientific or professional serious collector.  It also does not deal with the question should fossils be allowed for sale to the public.  The jury is still out on that one so this is an real world guide until the laws change. Right now almost anyone can (and perhaps should) own non scientifically important fossils


What is a fossil & what effects its value? A fossil is really just an impression (usually in stone) of a once living organism. To simplify the explanation it is either complete, such as a clam or trilobite, articulated, such as a small lizard, or disarticulated such as the bones found as part of most dinosaurs and large mammals. A question most people ask when they see any fossil is "Is it real?" Technically the answer has to almost always be no. There is no more "real" of this once living part of whatever the original creature was.  Each molecule has been replaced by a molecule of the surrounding material, usually some type of 'dirt' or mineral. Don't get to hung up on this real thing. Ask is it a good original copy? A good example are fossil fish which die and fall to the bottom of a lake or an ocean.  This now dead creature is shortly covered in silt, sand,  mud or other substance. Soon a combination of pressure (weight above), heat, and time start the formation of a future fossil. This is of course a simple explanation, but accurate.  Value we will get to below.

So is this a cast we are talking about?  All fossils are indeed casts. But the ones greatest in demand are "originals" not casts of a cast. So since we are all dealing with a "cast" or "copy" of this once living organism let's learn just a little about it before going further. We have found fossils of ancient bacterium as well as one hundred foot long dinosaurs and much in between.  The complete fossils are usually small in size and often common and thus lower in price. Disarticulated means "pieces."  This is by far the majority of both found and sold fossils.  A piece of a turtle, a piece of a dinosaur, a piece of a sea reptile.  These are almost always non scientifically valuable and so most people do not object to the finding and collecting of these. (But please, if you find a serious piece of fossil anywhere mark the spot (GPS if possible), and contact your local museum or university.  It just might be part of a great find and they may name it after you.) If it is not you still have your piece.  Articulated fossils are the rarest. The best example is the tyrannosaur named Sue found by the Black Hills Institute and now in the Chicago Museum of Natural History.  She was over 90% complete and while in parts, they fit together completely in such a way that she is called articulated, almost like in life. The missing parts were filled in and were either "made up" by experts or "cast" from other already found T rex bones. The rarity and preparation determine the price in all the above.

I've heard that fossils are actually fairly common. I find fossil sea shells every time I go to the Oregon beach?
     Actually fossils only seem common in some areas and for some creatures, such as fossil shells, trilobites, and other ocean creatures.  A much larger portion of water creatures fossilize then land or air creatures.  This is because water slows down decomposition in many cases, prevents scavenging more then on land, and has more plants and animals in it than on solid ground. Yet even so, only a very small percentage of water creatures ever become a fossil, perhaps less than 1 %.  But considering that the vast majority of animals that ever lived did so in or near water, the total number of specimens that ever lived is very great.  And much that was once water is now found as deposits on dry land. Those still under the water or deeply buried will have to wait for another age.
     But when it comes to land creatures it is likely that less than .1% ever fossilized.  Still, many hundreds of millions of years has seen much life and so some of it turns up in places that are visable and thus collected by humans of uncounted trillions of creatures.  Yet even with all the fossils that seem to be on the market it is truly rare that one ever makes into somebody's home.  As an example it is estimated that only something like 10% to 25% of all dinosaur species have even been found or identified.  So you only see a small portion of even the popular dinosaur species that have ever lived, much less the individual varieties. Only about 30 or so T Rex skeletons have been found of the many millions likely to have lived.  That is a rate at something like .000003% of all that ever lived.  So any fossils is rare and has both a scientific and a monetary value.

I have seen trilobite fossils where one sold on Ebay for $5 bucks and another one looking exactly the same went for $100 bucks. What gives?   
     Fossils, like stamps, coins, and comic books, have a value based on rarity, condition, and market conditions. A good way to see this is to use Ebays research functions (found on the left side of My Ebay) to make sure you are actually comparing apples to apples or in this case fossils with fossils. Sometimes similar looking fossils are actually two slightly different species;  one rare and one common.  Or one is larger than normal and thus more desirable.  Or the preparation of it was more complete or posed more interestingly.  Only research and knowledge can tell you if one is actually more valuable.  Always check out what has sold and for how much before bidding on anything on Ebay. It is also very important that the seller have a liberal return or satisfaction policy. Who you are buying from can be even more important than what and how much. A 100% satisfaction guarantee is your best defense.

 I have heard that many if not most fossils coming from other countries are likely to be stolen or smuggled?     
     There are some, especially in scientific or governmental circles, that have said this.  But "in general" it does not appear to be true or is at best, situational, a half or incomplete truth. Yes, there are problem countries that seem to have a more liberal approach to laws then others. But almost all countries now have laws to protect natural treasure and antiquities.  Again, if this is of great concern try comic books or another no problem collectible
     One does have to be careful that you are buying from a reputable seller.  But the vast majority of sellers are  honest and hard working.  It is possible that this fossil has passed through many hands up until now and somewhere, something not quite right has happened. (90% of all currency in the U.S. has traces of cocaine on it. Do you thing the majority of American's use cocaine?) That doesn't mean the current seller knows or had any knowledge about this.  And in about 95% of the fossils for sale, the scientific value is so minimal that no self respecting museum or university would want it.  If they did, they would likely either bid and acquire, contact Ebay, or alert proper authorities.  This rarely happens so it doesn't seen likely a major problem exists. Many of my fellow paleontologists and educators do monitor internet auctions and we rarely even suspect there is a problem.  This is not, of course, dealing with the philosophy of some, that NO Fossils should be in private hands.  Some people and institutions want to control everything. But since there is no law about buying and selling of "legal" fossils, no worries mate.

But how can I tell that I am getting a genuine legal, and fairly priced fossil? 
     There are no absolutes.  If you do your research, use reasonable care in picking who you bid with, and don't lose your head while bidding;  it should turn out fine.  I have investigated many "fake fossils" coming out of the worlds largest gem, mineral, and fossil show held every year in Tucson, Arizona where we are located for over 20 years.  Here is what I found out:

          1. There are a fair amount of fake or "re-prepped" fossils coming out of Morocco.  But upon closer examination of the entire story, the people who bought them paid such a low price that they were easily worth what was paid just on the "art" or "desk top uniqueness" value.  Who knows whether the trilobite hanging on your wall is the real deal? I won't tell if you won't.  If you bought an expensive specimen and were fooled then either you didn't take an expert with you or you relied too much on your limited expertise.  In either case we both know you let the thrill of a bargain overcome you good sense.  And yes, some (sometimes many) of the mosasaurs specimens were several different reptiles "composited together." But again the price is so relatively low that who really cares.  If you do then don't buy. It is really obvious to anyone who takes a few hours comparing things which are and which aren't.  And so on.

     2.  The same story holds for some (some say many) of the Chinese specimens. Again as examples some of the dinosaur eggs, fang tooth cats, turtles, and water reptiles are either composites, re-prepped, or rebuilds. The first is just several individuals in pieces are put together to look like one original.  And even top museum can be fooled (won't mention any names here;) and have been.  The second is just minor filling, painting, and more matrix or bone dust added. (This is done in most museums of the world and nobody gets hot about it) The third is where an egg has already hatched but is then turned upside down and " seriously re-prepped" until the bottom is re-matrixed (dirt put back on) and the top cleaned and prepped until it appears you have a whole unhatched egg.  But again, the price is usually much lower than a legitimate (x-rayed) specimen.  I do not approve of the dishonesty. But a little research and a look at the price compared to other specimens should tell much.

     It hurts when you find out that the Tarbosaur egg (Asian T Rex) is really already hatched and empty or the Keichousaur fossil has the tail of a different individual.  And very few Chinese fang toothed cat skulls are completely original. But I bet you got it at a bargain price.  And even the complete fakes often look better than the real thing and are only apparent to an expert, not your cousin.  Compare like you would the $500 bill you just got if it matters. If you are not a museum buyer you likely are not going to be hurt much if it is not 100%.  Almost none truey are, even at a museum.

In summation.  Fossils of any kind are rare to relatively rare.  Fakes are often told only by their price tags, Seldom is anyone really hurt with a fake. (unless you paid to much)  But to protect yourself do some research (Ebay and Google are good starting points), buy from a reputable dealer with a liberal return policy, and above all have some fun with it all.