Darren Tanke’s Gorgosaurus preparation 3: the snout appears

The first days preparation work went very well. Some crumbly bone was found in one corner of the jacket. Due to its poor state, all I could do was heavily glue it and use the heat from a desk lamp to dry it. The bone was in poor condition as it was from along the edge of the specimen where it was exposed and sticking out of the outcrop. Bone there is more exposed to rain, frost, and plant roots. Bone deeper in the hill is better protected from the elements and better preserved.

The glue we use is called Acryloid. It comes from the supplier as small plastic pellets which are dissolved in acetone. It can be mixed in different strengths as required, be it thin (for deep penetration of the bone), or thick (for glueing bigger pieces together). Use of the desk lamp as a heat source evaporates the acetone and speeds up the glues drying time. The glue is applied by plastic eyedropper. For fine gluing jobs I take a plastic eyedropper and cut the tip of it off far enough so I can attach the needle from a medical syringe (sharp point sanded off). I can then apply tiny amounts of glue where required.

Then I started to remove the dried and loose clay. Each piece was turned over with a small medical scalpel and examined for bone or bone impressions. Waste rock was put into a cardboard tray near the work area and emptied when full. After the first day, 4 trays were filled and emptied and this should represent a normal days work. If one is removing 20 trays of waste rock a day on a specimen this rare, fragile and scientifically valuable then they are going too fast and endangering the specimen! One has to go slowly and carefully.

I lifted one piece of rock and underneath it appeared to be several parallel rib sections. Still covered in sediment and dust, they were hard to see at first. They were glued and later cleaned off completely. I was surprised to see they were not ribs at all, but tiny teeth(!) from the left premaxilla (front end of upper jaws). Each tooth was about half the diameter of a pencil. Further work revealed the tip of the snout and more teeth from the left maxilla (main upper jaw bone), and the beginnings of the lower jaw, clamped tightly shut. By the end of the day a large section of the snout was showing. Everything was reglued and it has all weekend to dry out. So an exciting start!

More to come soon! All photos here and in the series are owned by Darren Tanke and the Royal Tyrrell Museum.

14 Responses to “Darren Tanke’s Gorgosaurus preparation 3: the snout appears”

  1. 1 Heinrich Mallison 02/11/2010 at 8:55 am


    Now can we please get this entire series (once it is finished) into a form that is understandable for TV people (i.e., less than 100 words, no words with more than three syllables, not more than five words in one sentence)? Maybe then they’d start showing something akin to reality when they show preparation in movies or series……



    • 2 David Hone 02/11/2010 at 8:56 am

      It would be nice wouldn’t it? There will of course ultimately be some kind of summary post and I’ll create a central post with links to every one of the others for easy reference which will be a start.

      • 3 Darren Tanke 09/11/2010 at 2:53 am

        That would be a great idea! Maybe it could become a reference point for media too?…..

  2. 4 Mike Taylor 02/11/2010 at 9:25 am

    Hi, Darren (via Dave). Just wanted to say that I’m really enjoying this series, and finding it very enlightening. Prep work has always been a mystery to me, and and it’s great to see how it goes, step by step. Much appreciated.

  3. 5 witmerlab 02/11/2010 at 1:41 pm

    This should be a fun series…s well as informative. Darren, I have yet to see your signature “Tanke Coke can scale bar.” 🙂

    • 6 David Hone 02/11/2010 at 6:07 pm

      I think there was a discussion about this last time out as European coke cans are around 330 ml and bigger than the North American ones.So the scale wasn’t that helpful unless reshooting Lord of the Rings and a necessairy to have Dwarf and Human sized coke cans on a Gorgosaurus….

      • 7 Kurt Kohler 02/11/2010 at 9:48 pm

        Irrelevant really, but the US Coke can in front of me says it’s 355 mL, i.e., larger than the European 330.

        Neat stuff about preparation. I never really knew what all was involved.

      • 8 David Hone 02/11/2010 at 10:45 pm

        Perhaps it wasn’t North America then, but I *know* I saw a conversation about this somewhere recently online about coke-can sizes as scales on dinosaurs!

  4. 9 Heinrich Mallison 03/11/2010 at 8:26 am

    they introduced a smaller new can here recently, obviously not at a proportional price. Further confusion to ensue…..

  5. 10 John Scanlon FCD 04/11/2010 at 6:25 am

    Coke cans are 375 ml here in Australia, a standard Schooner glass.

    Did you really just toss the clay? Don’t you dinosaur folks ever look for itty bitty fossils (i.e. normal-sized vertebrates), e.g. by sieving matrix? Nearly all the prep work I do is acetic acid on limestone, and nothing is discarded but what passes the finest sieves we have… but sometimes the fine fraction isn’t good for much, it’s true.

    Can’t wait to see the skull though.

    • 11 David Hone 04/11/2010 at 7:52 am

      With the prep work I’ve done, you are generally peeling off mm s of rock at a time so are effectively checking everything visually as you go and keeping an eye out for small bones, teeth etc. and often you will check the discarded matrix as well.

  6. 12 Darren Tanke 04/11/2010 at 6:30 pm

    Regarding the comment by John and followup by Dave. We are saving some matrix, but just for cosmetic effect at the very end of the preparation. The rock is being taken down and removed piece by piece and some small fossils are exposed that way. But in the big scheme of things, the items being found are rather insignificant- things like crocodile teeth, Champsosaurus (an aquatic eosuchian reptile) vertebral centra, etc. Such items can be found by the dozens in Dinosaur Provincial Park on any given day. I am saving what small fossils I do find- if unwanted by the Collections Department, it can be forwarded to our Education Department for educational programs or hand samples. We are not screening matrix from this dinosaur as there are several other active screening projects of microvertebrate sites in our museum already. I have had to screen matrix from specimens a couple times in the past when a small bone piece was inadvertantly lost. All matrix was screened to relocate the bone fragment. It is a lot of work to relocate a small piece, so we do our best not to accidently lose anything.

  1. 1 Gorgosaurs preparation review and Q & A « Dave Hone's Archosaur Musings Trackback on 26/11/2010 at 9:42 am
  2. 2 Darren Tanke’s Gorgosaurus preparation: final roundup « Dave Hone's Archosaur Musings Trackback on 22/02/2011 at 8:59 am
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