Rachel Narducci
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Hi David, I’m not really sure about the actual geology, but it looks to me like an inclusion of some type of mineral (maybe calcite) within a rock. And that mineral is eroding quicker than the surrounded rock, making it look more jagged like teeth.
I honestly do not know how to ID these, so you might want to disregard my response, but it kind of resembles Cheloniidae to me. Of course, it could also just be a very thick piece of Hesperotestudo plastron…
Hello,
I believe these are angulosplenials of Anurans. I’m not sure how to narrow down to genus level or even whether it’s from a frog or toad though.
– Rachel
Hi Kelly @kelly-lunt ,
It’s so small it’s difficult to see, but I would guess that it is a piece of a coral!
– Rachel
Hi Marjorie @marjorie-laster,
I would agree that these are phosphate pebbles. However, it’s a bit hard to see all of them, especially some of the smaller ones, so you could have a fish tooth. Attached is an image of what this might look like.
– Rachel
Hi Rob @rob-mccannell ,
It’s a bit hard to see, but I think this might be a bivalve fragment, specifically from a pecten. Not sure of the specific type though.
– Rachel
Hi Kristin,
I’m almost certain these are bivalve fragments, specifically from a pecten. I do not know much about the Aurora fossils, so I, unfortunately, could not give more of an ID than this. I hope it’s helpful though!
– Rachel
Hi, @pdon-pinkham,
I think preparation for this specimen first comes down to; what do you want the outcome to be? Are you hoping to remove all of the matrix around each individual specimen? If this was for my personal collection, I would probably keep the entire block intact and just scrub it down with a toothbrush and some water. Maybe chip away some of the limestone around each individual specimen to reveal more of the face using a carbide tool or air scribe (I’m not sure how hard this matrix is). If you have no time constraints, I know people who just place these blocks in their yards and allow the rain to do the work. I have never used acetic acid in fossil prep, but when we use formic acid, it is a 7% concentration mixed with water. I’m not sure if this would be best to use on your specimen though because there are so many individuals in the one block. Also, these acids are considered hazardous waste, so they will need to be disposed of properly, and that will vary depending on your location.
@rebecca-mussetter If this were a game show, my first guess would be a coral. That is what the texture most looks like to me. Can you see any of it coming out of the other side? It’s possible that it could be the porous area, maybe around the skull of a vertebrate. With all of the invertebrates, I would guess whale. (Like from a whale fall where invertebrate organisms colonize a dead whale skeleton.)
@joyce-drakeford Thanks for you question and for attending the webinar! So, there are different grades/levels of the polyethylene foam. If you are not using the archival one that might be why it is yellowing (the archival kind should not yellow under the proper conditions). So if it is the archival type, the next, probably most common cause, would be exposure to UV light. That is mostly okay for your fossils but it could break down the glues over time. It could also be caused by things that would harm your fossils over time like heat/humidity or oxidation. I also found this PDF with some info: http://fxi.com/assets/pdf/up_06_quality/Discoloration_Info_Sheet_-_111010.pdf
These are the associated Mesohippus leg pieces! Better late than never! And definitely a great find.
Hi Lee @lcone,
I haven’t had a chance to clean up the possibly-associated Mesohippus leg pieces, but I’ll let you know what we do with them once we get to them! That maxilla was an awesome find and glued together perfectly.
