Sorry, I think this is just discoloration of the rock.

Yes, I agree with @samantha-ocon.

@samantha-ocon is correct, there are no Favosites in the Mesozoic. I was looking at a geological map of the area and there is a Paleozoic Plutonic Complex nearby. Plutonic implies that it is igneous in nature (so no fossils) but where it is a “complex” I don’t know if there might be a sedimentary layer. Favosites are a tabulate coral meaning that…[Read more]

There is a pay-to-dig site outside of Florissant National Monument.

@samantha-ocon and @shane-duel While the area does have Paleozoic limestones (I think specifically Missippian limestones like the Warsaw Formation and St. Louis Formation) I don’t see coral structure continuing throughout the rock so I think it’s a geode.

I’m thinking concretion. @semmy-nou, if you scrub it with water will shell appear? If not it’s a concretion but if if you see shell underneath it’s probably some sort of snail. Right now there is too much limestone on it to tell.

@samantha-ocon@sarah-coates I’m tempted to say mineral growth but they could also very well be fossil stromatolites given the geological context.

@sarah-coates@samantha-ocon I think these are gypsum crystals growing in mud cracks.

Sadly, this is a pseudofossil. The patterns are formed from sedimentary and deposition processes.

In short, while listed as Orthoceras by many dealers, it may be something else like Arionoceras or Michelinoceras.

@semmy-nou Traditionally this has been classified as Orthoceras, however, a paper by Gnoli 2003 shows that there is high diversity in these sorts of straight cephalopods (squid-like creatures). I also read something that is restricting Orthoceras to the middle Ordovicean and cephalopods in other times have other names. This black limestone is…[Read more]

This appears to be a flattened crinoid (sea lilly, which is actually an animal) stem.

Hi @semmy-nou! Nice specimen. This is an ammonite, a relative of the modern day nautilus. Because of the minerals in this specimen, it’s likely from Madagascar. Do you have a picture of the other side? The cut pieces are hard to ID because they don’t contain many diagnostic features (although they are pretty). However, you can eliminate some…[Read more]

@semmy-nou At first glance this looks like a brachiopod. However, looking at the sides would help to see if there is a break in the rock (which might suggest it’s something else). Do you know where it was originally found?

@semmy-nou This is a trilobite. These are arthropods that can be identified by the three lines that run up and down the animal. Do you know where it was originally found and can you get a picture of the head (we call it a cephalon)? This will help further with identifying which trilobite it is. I’m going to tag @cameron-muskelly and @samantha-ocon…[Read more]

I agree with @jbauer. It looks like a modern one. I believe there are two species on the OR/WA coast.

@layden-flowers it could be petrified wood. Can you do these individually from other angles please? That would help!

These look a little modern to me.

@hunter-thurmond Sounds good! Seems like a better fit than Equisetum.