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Probable dyrosaurus - advice requested


Aurelius

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I obtained this partial crocodile skull and jaw some time ago, and haven't done anything with it yet. It's from Morocco, and was sold as sarcosuchus, though I imagine it's actually dyrosaurus. No idea whether it's just one specimen, or a mixture of bits. The teeth are glued on.

 

Several of the pieces are also so fragile that they basically crumble when touched. Is there a method I should be using to stabilise them?

I know very little about crocs, but I would love to get this to some kind of displayable state. I can digitally sculpt and 3D print missing pieces later, but my main problem at this stage is actually understanding what I have. Many of the bits are - and I assume will remain - unknown bone fragments, but many are large and identifiable - with the right references and knowledge (which I don't yet posses). Is there any advice that anyone could offer which isn't "put it in a box and forget about it"?

I appreciate that I must sound like an idiot to people that know their stuff - my specialism is ammonites, which I can prep to a very high standard, but the only vertebrates you find around here are ichthyosaurs. I don't exactly need my hand held, but a few pointers would be very much appreciated! 

 

 

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at the second picture, the small object at the right are fish vertebrae, I think

and the big piece at the first pictere totally on the right is the parietal or the squamosal ( I'm not sure about this)

The second part above the mark of 16 inch is probably the angular or the surangular.

I also see some teeth and some jaws

the second piece above the mark of 21 inch is the frontal I think

 

I'm not sure of this determinations

 

Greetings 

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That looks like a dream project. :wub:

 

Much of the typical Moroccan from Khouribga is generally very soft and easily break. I personally use cyanoacrylate to stabilize the bones. Start with the broken areas, those are the most fragile. The cortical bone is generally a little harder. And if you glue the matrix onto the bone it will be very hard to clean. So clean first and only stabilize the cleaned areas locally. Use a dental pick to carefully scrape away the matrix after you've stabilized the cleaned areas. If the matrix is also glued, upon removal it will likely take a thin layer of cortical bone with it. Use a microscope. It's possible without. But if you want to do it properly you really need a microscope imo. When done correctly it will be possible to remove nearly all the matrix with little to no damage.

 

It looks like you have most of a skull. You seem to be missing the premaxilla but have most of the left and right maxillae. There seems to be what looks like a jugal, the skull roof and maybe a partially braincase. With some effort it's probably worth putting this skull back together and maybe filling in the blanks.

 

What you could do, is try out photogrammetry. By photographic the separate pieces, you can scan them and get digital copies. you can then mirror these copies and more easily figure out how things fit together. You could even try to 3D print them if you have that possibility.

 

Here is a tutorial on how photogrammetry works:

 

Olof Moleman AKA Lord Trilobite

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Thanks very much :) I'm glad to hear someone say that it looks like a project that has some potential! 

 

I do have a 3D printer, and have done quite a bit of photogrammetry in the past. I also have virtual reality, so I can sculpt objects quite easily in that, and then 3D print them. I'll get to work first in cleaning the bones and stabilising the fragile bits, and then I'll try and assess what I need to 3D scan or create from scratch.

If anybody can suggest a source of information which might help me to identify the bits of bones, I'd be very grateful.

I'll update the thread when I have something to show for it.

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Been having some trouble cleaning these bones. The matrix, whilst it looks soft, is actually very hard indeed. It's really difficult to get off - to the point where this bone snapped in half as I tried to take a small piece off, just after I took this photo (a new break, not the one visible). However, it was a clean break and has glued perfectly.

 

I'm wondering if the bones and matrix may have been covered in something to try and consolidate them. Either that, or the rock is just very tough.

 

I could try my air pen on it at low power, or a dremel or something. Or I could possibly use acetone to try and dissolve any solvents that may have been used. Or just soak the matrix (not the bone) in water to soften it up?

 

Hard to know what to do for the best. Suggestions would be most welcome :)

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To prevent such breaks it's probably best to consolidate the bone on one side first when it's clean. And when the one side is stronger, then start cleaning the other side.

Yes it's common for the matrix to be consolidated as well. You can find out if this is the case on larger chunks. The outside will be a bit harder and the inside will be quite soft. the other possibility as you've stated is that the matrix is just rather hard naturally. Using acetone or water might be a good idea to soften the matrix a little. I would suggest using a small brush to very locally soften up the matrix to see if that works. I've also seen wood glue used on Moroccan fossils, which softens nicely in water.

 

Dremel or air pen might work, but it might also shake apart the fossil. I would suggest leaaving that as a last resort and just work slow with hand tools.

Olof Moleman AKA Lord Trilobite

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Thanks very much - I can confirm that water does the trick. The matrix is incredibly absorbent, so it softens when I dab water onto it with a brush. It still takes a lot of effort to get off the deeper bits though. I have now pretty much finished cleaning the bone pictured above. Unfortunately I managed to break it several times, although in most cases some superglue fixed it. I'm hoping that the knowledge I gained on this one will help with the other bones. 


I found this tooth in the matrix - I assume it's from a fish.

 

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