Photo of the Day #947: Tyrannosaurus toe


A few weeks ago I started prep work on a Tyrannosaurus rex toe bone recovered from Montana's Hell Creek Formation and kept at the New Jersey State Museum. This is how the gypsum-encrusted bone looked when I started...


... and this is how it looked at the end of last week. There's still a lot of work to do, but it is encouraging when you start seeing more bone than gypsum.

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cool. funny, i don't i could have told what was bone and what was quartz if i didn't already know what a t. rex toe bone looks like (thanks to a recent visit to the Los Angeles Museum. See, museums are useful!).

Looks like you could make use of a microblaster! I've prepared a bunch of fossils from CA that have quite a bit of gypsum on them; using a microblaster has yielded pretty good results so far. Man, that is A LOT of gypsum...

i know zero about the sort of work you do and whats involved,the details anyway,but i would have thought by this time someone would have come up with a "modern" way of freeing up know,lasers,chemicals,robots--it sounds like this work is still in the 1800's,with dental picks and such..anyway..nice work,good luck with the rest.

To get through harder matrix, preparators make use of air-powered chisels, and sometimes use microblasters as I mentioned above (i.e. a sandblaster). Otherwise - chemicals are used to dissolve some types of matrix. However - just think about it. We're talking about removing rock from bone - all in all not a very complicated process. Hand tools have been used to carve stone for millenia, and clean fossils for ~200 years - they've stood the test of time.

Oh, and they're cheap, easy to use, and reliable. It's better to not overcomplicate things.

Thanks for the comments and suggestions, everyone. An air-powered chisel or similar tool would probably be a big help, but all I have to work with are dental tools, knives, and other miscellaneous things. Even though I am doing prep work the museum does not presently have a dedicated prep lab, so I am doing the best I can with what I am have got. It takes a long time, but that is probably for the best. In some places the gypsum crystals sit over more fragile areas of crumbly bone, so slow-and-steady is better when dealing with those parts! There are many more bones from this skeleton, though, so after I finish the toe bone I might invest in some tools of my own to help things along.


That's the one issue with air scribes and microblasters - they're way more expensive than hand tools. *However*, I've seen a paper recently on a chemical that can be used to dissolve gypsum (as an application to fossil prep), which seems like it could be really useful in a lot of cases... including this. Jeeze, it looks as if that bone came from an evaporite deposit!