Tribolite fossil or impression on rock?

[Medusadawn]

Ok guys! Have taken your advice, stopped looking for bones and focused on sea related shapes, found this guy yesterday, looks like it might be animal rather than plant? Help please! Have a SMALL Bic lighter for scale.

Edited July 29, 2019 by Medusadawn
More information

[Medusadawn]

[Rockwood]

Yep. Looks like a mold of a trilobite pleural to me.

[Kane]

I’ll be the contrary voice on this... The shape radiates in a fan-like way, and what one may take as pleura lack uniformity. But perhaps removing some matrix to reveal more might help with ID.

[Fossildude19]

This looks more shell like, to me, than trilobite.  

[FossilDAWG]

I'm in the shell camp.  The divisions between segments seem to be folds so the whole structure seems to be one continuous piece, as opposed to juxtaposed segments of a trilobite carapace.

 

Don

[Rockwood]

[Kane]

Just now, Rockwood said:

It's all good, Dale. Your gut instincts pay off more often than you might think.  

[Medusadawn]

I thought shell initially also, but if that’s the case it’s broken in just the right spot to mimic tribolite patterns. Thanks guys, gonna keep trucking.

[Medusadawn]

Have another question!! How do you guys reveal more, or “remove matrix”??

[Kane]

11 minutes ago, Medusadawn said:

Have another question!! How do you guys reveal more, or “remove matrix”??

If you don't have an air scribe / eraser setup (most people don't!), you can see if using some hand tools like a sturdy sewing needle and some patience can help remove some of what is covering the fossil (the fossil is hosted in the matrix). Of course, if the matrix is way too hard, other methods may need to be explored. Another alternative would be to return to that site and collect more from there, and you may encounter another example that will show more detail.

 

Our Fossil Preparation subforum is loaded with helpful threads ranging from the most basic prep setups to the most advanced if that is the route you would like to take. If not, finding more is its own kind of fun, too!

[fifbrindacier]

Hi, i'm also in the shell camp, this is scallop looking.

[Mark Kmiecik]

It looks like a brachiopod to me. However, I have been wrong on many occasions, and sometimes even when there was no occasion.

 

You can get a pin vise and pins for it online really cheap and slowly and carefully pick away the stone matrix around the fossil. Each grain removed reveals a tiny bit more until eventually you expose pretty much all of what is there. It is a painstakingly slow and tedious process with handtools but the results are immensely satisfying. The steel point of the tool should be harder than the rock, so carbon steel is commonly used.

[Medusadawn]

Thanks so very much to all that replied and advised!! It is well and truly appreciated!! I’ve been using a Dremel- like tool to remove the casing from it. It’s actually a nail filer for dogs, with different stone bits, have had some luck with it, will post pics when I get done. And yes, I’m wearing a mask! Beginning to think that it is a shell as well, dreams crushed again! : ) But I LOVE sanding, stripping material so I’m happy! This is a spot where I got a chunk of material off of the corner!

Edited July 30, 2019 by Medusadawn
Added photo