Fake Mosasaur Jaw: Beware

[TMNH]

Several years ago, when I was less knowledgable about fossils, I purchased a mosasaur jaw from a museum gift shop (proving that you can't trust anyone these days). Naturally, it turned out to be a composite from Morocco.

I decided to soak it in water for a few hours, so that I could expose the real teeth, but just minutes later the whole thing completely disolved! The "matrix" surounding the teeth turned out to be sand, glue and a few chunks of animal bone.

I am embarassed that I fell for such a poorly made fake, but at least now I can easily recognise similar frauds.

Has anyone else had a simiar experiance?

[tracer]

i will tell you that those things are everywhere, and they've gotten much better on the individual teeth in matrix at making them look real. a key point in spotting fakes is to not see a bunch of bad ones and assume you can now spot all fakes. the good ones are the problem.

there is some stuff that is completely real but from my experience at fossil shows it's very small amounts. and mosasaur teeth are just one of many problems. a lot of the time, the higher the price, the better the fraud, because it's more worth the crook's time to do it well.

knowledge is power, so welcome to a powerful place to gain knowledge.

[Frank Menser]

Had a similarr situation with a croc jaw I got from Morocco. Since it was very heavy I decided to trim off excess matrix. When I chipped near the back of the skull I found that under a layer of "sand" type matrix was plaster. I eventually exposed the entire pocket and found that only the part from the eyes forward and the snout was real.

[Frank Menser]

Several years ago, when I was less knowledgable about fossils, I purchased a mosasaur jaw from a museum gift shop (proving that you can't trust anyone these days). Naturally, it turned out to be a composite from Morocco.

I decided to soak it in water for a few hours, so that I could expose the real teeth, but just minutes later the whole thing completely disolved! The "matrix" surounding the teeth turned out to be sand, glue and a few chunks of animal bone.

I am embarassed that I fell for such a poorly made fake, but at least now I can easily recognise similar frauds.

Has anyone else had a simiar experiance?

By the way, soaking any skull in water is really a bad idea. I know someone who soaked a China sabrecat (real--not fake) and ended up with a bucket of mud and bone fragments.

[Rover]

Never had that happen to me, fortunately. I will have to be careful with any skulls I buy, though... While it's perfectly alright to have the matrix surrounding a solitary tooth come apart when you soak it (in order to get the matrix off), having the whole fossil disappear on you is somewhat less alright.

[Claw]

The creativity behind some of the fakes is in a way quite impressive. Too bad the skills aren't used more productively. I guess fossil collecting is like fine art collecting, with the values going higher for unusual specimens, so goes the incentive for fakery. A couple of comments here are good reminders that soaking in water and things falling aprt is not necessarily the sign of fake!

[Harry Pristis]

Frank Menser Posted 30 May 2010, 11:39 AM

By the way, soaking any skull in water is really a bad idea. I know someone who soaked a China sabrecat (real--not fake) and ended up with a bucket of mud and bone fragments.

Thank you, Frank! I was afraid that TMNH and others here would miss the BIG lesson:

Never re-wet with water a dried fossil!

You have to prep it as you find it. Putting a dried vertebrate fossil back into a water bath is asking for a huge problem.

[Roz]

I didn't know that. I have always soaked in water and then cleaned and dried. Very good to know.

[Auspex]

These "composite" jaws, hand crafted in Morocco, have been all over the market for a while now, and the artisans are going to greater extremes to strike a salable "pose".

There are a bunch on Ebay right now, and this one is notably "artful".

The seller does make passing mention that the matrix is "reconstituted", but alludes that the jawbones are genuine Mosasaur...the teeth probably are, but probably not associated and probably heavily restored.

 

Just say "NO" to fakes!

[siteseer]

Thank you, Frank! I was afraid that TMNH and others here would miss the BIG lesson:

Never re-wet with water a dried fossil!

You have to prep it as you find it. Putting a dried vertebrate fossil back into a water bath is asking for a huge problem.

Harry,

I saw a close call some time ago. An expert preparer still immerses skulls with lowers in water to soak off the lowers so he can determine the best pose (jaws closed or open) and get a full idea of what's real. He left one in almost too long. Parts of the skull started to fall apart and one lower broke up but fortunately in several still largely connectable pieces rather than fragmenting to the point that planes of contact were lost. He said it was better/faster than trying to scribe through glue. He screened the mud for every bone piece and tooth flake afterward.

It turned out okay and it was a good lesson in how fragile a seemingly solid skull can be - good for a beginner to see.

[tracer]

although putting an unstable fossil in water is a significant risk, statements including "always" or "never" are absolutes and therefore frequently in error.

"fossil" is too broad and too generic when discussing how to physically handle and deal with found or purchased items. not all fossils are the same. some are phyllosilicate smudges on shale, and some are monolithic chert.

here's what i'd go with as a concept. water is a solvent of many things. if the nature of your thing is questionable or unknown to the extent that you are not sure water will not be a solvent for it, then don't put it in water. but the same could be said of other solvents. if you're not sure your "fossil" wasn't glued together with a glue for which acetone is a solvent, then don't put the fossil in acetone.

unprepped or otherwise funky fossila that come to hand are a test of your eye and analytical skills regarding the best way to deal with them. some are best left alone. some are best pranked with.

water is one of many tools to use in dealing with fossils. sometimes i use it - sometimes i don't. if a fossil is permineralized with chert, and it's grubby on the outside, i'll wash it. if i know a fossil is full of salt, i'm usually going to soak it for long periods in water, regardless of risk...

your mileage may vary.

[megateeth]

The first part of his declaration is confusing

The specimen listed are real fossil jaws and teeth that are excaveted when the preparatory Moroccan craftsman removes actual insitu (as found) fossil jaw bone sections and real teeth from blocks of brittle, crumbly sandstone matrix and then composites (reassembles them from parts) back onto a block of original crushed matrix, which is then stabilized with a thin glue solution making the whole display very stable.

The second part is more clear.

These are NOT found in the ground as you are seeing them, they are composites that have been prepared and assembled for display.

Of course this is buried in the text.

Still it seems that for a price of $75 it is a nice display piece for someone that could not afford or find a real one. I bought a few teeth in a jaw fragment at a show for a friends son that loved "dinosaurs". I paid $25 for a few teeth in a jaw and matrix that I knew it was not real but it gave him with a writeup on the Mosasaur and added that it was a composite. It gave him an idea outside of a book as to what they would have been like. His parents say it really made him that much more into science. So if he gets into fossils and someday resents me when he figures out they are fake I can live with that.

Edited June 1, 2010 by megateeth

[TMNH]

Thank you, Frank! I was afraid that TMNH and others here would miss the BIG lesson:

Never re-wet with water a dried fossil!

You have to prep it as you find it. Putting a dried vertebrate fossil back into a water bath is asking for a huge problem.

Thanks for the tip. I did not realize that it was such a bad idea.

When I decided to soak the jaw, however, I knew that it was a fake. The actual "bone" was mostly sand and glue, but it's creator also mixed in some crudely cut pieces of animal bone (one looked like some part of a leg bone and was obviously sawed into a chunk!). Although I didn't realize the disasterous consequences of soaking a fossil bone, I would never have soaked it if I had thought that there was a possibility of it being real.

[Harry Pristis]

. . .

Still it seems that for a price of $75 it is a nice display piece for someone that could not afford or find a real one. I bought a few teeth in a jaw fragment at a show for a friends son that loved "dinosaurs". I paid $25 for a few teeth in a jaw and matrix that I knew it was not real but it gave him with a writeup on the Mosasaur and added that it was a composite. It gave him an idea outside of a book as to what they would have been like. His parents say it really made him that much more into science. So if he gets into fossils and someday resents me when he figures out they are fake I can live with that.

I agree with Bill on this point. Seventy-five dollars for a handfull of mosasaur teeth in a representation of how they were positioned in life is not a bad deal at all. The bone that comes out of the Moroccan phosphate is oh-so soft! Think "crumbly."

I looked at a few of these jaws at a wholesale show a couple of weeks ago, and I'm impressed. With vertebrate fossils, there is restoration and, beyond that, there is interpretation. These mosasaur jaws are interpretation.

When you try to apply invert-collector or shark-tooth-collector standards to vertebrate fossils, you are going to miss out. Learning the differences between real, restoration, and interpretation is what promotes newbies to advanced collectors.

[Sundancer73]

Valuable lesson Harry. Thanks! I may have eventually done that.. I had NO idea..

~Mike

[seanm]

I have one of these "fake" jaws which i use when i do talks in schools. It cost me £14 which is about $20. Its cheep but the kids love it as they can handle it and im not worried about it getting damaged. The same with some of the trilobites I have from morrocco I know fully well that 80% of them is made out of car body filler but they are cheep and at the end of the day you get what you pay for.

[Auspex]

I have one of these "fake" jaws which i use when i do talks in schools. It cost me £14 which is about $20. Its cheep but the kids love it as they can handle it and im not worried about it getting damaged. The same with some of the trilobites I have from morrocco I know fully well that 80% of them is made out of car body filler but they are cheep and at the end of the day you get what you pay for.

Perfectly good uses, and good reasons for this class of "fossil". I wish they were marketed this way; too often they are offered as...something else...to the inexperienced.

[Mr Coats]

I was over at M.A.P.S. fossil show over in Macomb, Illinois last March. They had a ton of stuff. A lot of was certainly real, but there were also a lot of those fake Mossasaur jaws being sold. Also, some of the fossil skulls had a considerable amount of plaster reconstruction.

[NZ_Fossil_Collecta]

you are right, gift shops cannot be trusted (it may not be thier fault in my case, the label was japanese) i bought a spinosaurus tooth at a japanese natural history museum, it still had the sand on it and i thought it was just a dirty tooth. however the tip had come off and been glued back on with that cheap field glue that looks like dirt. only found this out when i got back to new zealand. (oh well, superglue to the rescue once i use solvent on it)

[paulgdls]

soak in acetone or similar solvent to dissolve consolidant. May need to dry and resoak a couple of times to ensure removal. Then remove sand (grain by grain if necessary) using very sharp end of a throwaway knife (may need to use magnifier to see what you are doing). Stop if enamel is getting damaged in the process. As has been stated elsewhere the sand is often stuck onto the fossil to hide breaks or damage, sometimes in the field when the fossil is first found.

regards

Paul

Edited November 20, 2013 by paulgdls

[Mr_billy_bob]

Same exact story, I actually also got it at a museum as well. Can't trust anyone these days I guess.

[-Andy-]

Thank you, Frank! I was afraid that TMNH and others here would miss the BIG lesson:

Never re-wet with water a dried fossil!

You have to prep it as you find it. Putting a dried vertebrate fossil back into a water bath is asking for a huge problem.

Not always true. It depends on the fossil type.

I've poured water over my very-brittle Chinese turtle. A risk, I admit. But I did it carefully, and it worked well.

I've also soaked my sarcosuchus scute in water overnight with no issue.

[LordTrilobite]

This topic reminds me.

I had the idea to make an in depth tutorial thread on how to recognise real and fake mosasaur jaws. With detailed photos, what to look out for and such. What's real and what's not. On the internet there are a number of such guides. but I generally find that they lack good examples for the most part.

So I planned to make a guide myself. But what I lack is good photo's or the most terrible examples. I have a number of specimens of real jaws, real teeth with roots. And real teeth with fake roots. But I don't have any composite "jaws" as example.

So if anyone has some good photos to share. Send me a message.

although putting an unstable fossil in water is a significant risk, statements including "always" or "never" are absolutes and therefore frequently in error.

"fossil" is too broad and too generic when discussing how to physically handle and deal with found or purchased items. not all fossils are the same. some are phyllosilicate smudges on shale, and some are monolithic chert.

here's what i'd go with as a concept. water is a solvent of many things. if the nature of your thing is questionable or unknown to the extent that you are not sure water will not be a solvent for it, then don't put it in water. but the same could be said of other solvents. if you're not sure your "fossil" wasn't glued together with a glue for which acetone is a solvent, then don't put the fossil in acetone.

unprepped or otherwise funky fossila that come to hand are a test of your eye and analytical skills regarding the best way to deal with them. some are best left alone. some are best pranked with.

water is one of many tools to use in dealing with fossils. sometimes i use it - sometimes i don't. if a fossil is permineralized with chert, and it's grubby on the outside, i'll wash it. if i know a fossil is full of salt, i'm usually going to soak it for long periods in water, regardless of risk...

your mileage may vary.

I agree. Never say never.

Salt water fossils for example normally need to be submerged in fresh water for long periods of time to disolve the salt crystals. If this isn't done, when dried, the salt crystals expand and break the fossil apart.

Edited June 8, 2015 by LordTrilobite

[Macrophyseter]

well, i one tried to remove all this matrix from this shark tooth i bought from the california science center, but when I soaked the entire tooth into water, literally everything dissolved except for the tooth part (what do you call that again?) and some glue. Shame, that they decided to just scramble up a random poor grade shark tooth, glue it together with some fake material, and cover it with "matrix" so that it doesn't show. Speaking of that, When I once decided the scrape off some matrix from a different tooth also from the science center, i got so lucked out- The real part turned out to be from a CARCHARODON ANCESTOR (I think paleocarcharodon), as the tooth was serrated and showed evidence that it was from morocco, which the other teeth did not have, as they were supposed to be from otodus (I wonder why 99% of all shark teeth you find in gift shops are from otodus obilqus, why not some other?)

[RJB]

I was fooled just this last January. I was used to seeing all the 'easy' fakes and then saw these (pics here) and bought these. All fakes. Purdy good fakes if you ask me. But I was lucky enough to get one real one. I only paid $60 for these so I wasn't out a fortune.