Prepping some White River Fossils - Guidance and advice needed!

[Opabinia Blues]

I have a few really nice fossils from the White River Formation of northeastern Colorado that I need to prep, and given I am a beginner at fossil prep I would really like to gain some advice and guidance from people with experience do I don’t accidentally damage the fossils. 

 

 

 

The first fossil is an Oreodont skull. The skull is mostly intact, and I was able to extract it from the field without using any glue or stabilizer or consolidant or anything like that, so this fossil is in its “natural state.” The zygomatic arch and upper tooth row are crumbling, but otherwise everything else that I can see is there appears to be stable. The other side of the skull appears to be still mostly encased in matrix, and is likely to be better preserved. What’s everyone’s opinion on whether or not I should apply penetrant stabilizer directly to the bone before prepping to help keep it intact? 

 

The second fossil is a jaw bone, tentatively identified by me as Subhyracodon but I will need to reveal the teeth to know for sure. There are several large cracks throughout the bone (as can be seen) but the entire bone is still in one piece due to application of PaleoBond penetrant stabilizer in the field. There is matrix in between the larger cracks, I imagine I will have to pull it apart one piece at a time, clean the pieces, and then glue them back together. 

 

I don’t have any specific questions at this point other than about the overall process. It would be great if those with experience could briefly go over how they would go about prepping these fossils would be great. Is there anything I should avoid, be careful of, or watch out for? 

 

Equipment I have includes an air scribe with compressor, dental picks/tools, and the full suite of PaleoBond glues and stabilizers, including the debonding solvent.

 

Thanks in advance!

 

*These fossils were collected legally on privately held land in Weld County, Colorado, with full landowner knowledge and permission.

[Kane]

Let me tag @Randyw who has done great work with oreodonts.

[hadrosauridae]

IF the fossil appears to be highly fractured and unstable, I would recommend applying a stabilizer directly to the bone as you expose small portions.  Dont apply it to bone still covered in matrix or else you'll be making it harder to prep.  If you go slow and consolidate as you go, you'll be good.  Also, I would recommend a plastic based consolidate like PVA, Butvar or Paraloid.  Using a cyanoacrylate like PaleoBond PB-02 on the surface will make future detailed cleaning much harder.  PB-02 is good for solidifying the broken ends of bone before rejoining.

[jpc]

4 hours ago, hadrosauridae said:

IF the fossil appears to be highly fractured and unstable, I would recommend applying a stabilizer directly to the bone as you expose small portions.  Dont apply it to bone still covered in matrix or else you'll be making it harder to prep.  If you go slow and consolidate as you go, you'll be good.  Also, I would recommend a plastic based consolidate like PVA, Butvar or Paraloid.  Using a cyanoacrylate like PaleoBond PB-02 on the surface will make future detailed cleaning much harder.  PB-02 is good for solidifying the broken ends of bone before rejoining.

I just posted the same comment on your field report.  Avoid PB in the field,  Here in the lab, you can put small amounts in the cracks before you clean it.  I am a strong believer in air abrasives for White River bones.  I have been using one for so long that I cannot imagine prepping them without it.   What size air scribe do you have?  You can still do a lot of prep with just an air scribe.    

[Randyw]

4 hours ago, hadrosauridae said:

IF the fossil appears to be highly fractured and unstable, I would recommend applying a stabilizer directly to the bone as you expose small portions.

I’ll second this. If this was mine I’d  use a super thin super glue or other similar bonding agent and let it wick into the cracks on the exposed side. Then I’d consolidate the heck out of the exposed side. I use a brush for this step. Any extra on the surface can be gently removed by wiping with acetone. I strongly suspect the other side while it may be in better shape will also be highly fractured (although you may be lucky) so go slow and consolidate and glue as needed as you go. If you even suspect a fracture...consolidate! It’s easier to remove extra consolidation then to get broken pieces back in the exact spot. Some of these specimens will have matrix that when you get close to the bone then the piece against the bone will almost jump off others will be like the matrix is welded on. And some will have spots of both. There will sometimes be spots where the bone and matrix will be the same color. A little repeat little spritz of water will often highlight the difference. I only use a little and wipe off as much as possible as soon as possible. I don’t have an air scribe so can’t help you there. I do all my prepping with an electric engraver and picks... the engraver to get close and picks to finish. But once again watch out for hidden fractures! If something looks like it may be widening, then glue! LOL! Looks like you got some fun time ahead of you! Good luck!

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