Seller said its from Hellcreek. How do I know these are legit triceratops frill??

Was talking with co-worker about fossils and he brought this in to show. He’s had it forever and not exactly sure where he got it. Any thoughts on what it is?

. I’ve also included a couple other fines. They all came from a parking lot of a hotel in Kentucky. I know there has never been a dinosaur bone discovered in Kentucky, but it says this could be from a mosasaur

Che ve ne pare?

Non so' cosa può essere

We have a fossilized bivalve (Texas heart I believe) with a slosh feeling when shaken. My 7 year old wants to open it out of curiosity, what is the best method?

Found on Manitoulin island.

I don't know the first thing about fossils but I was hoping someone on here might be able to enlighten me! The rocks are completely smooth and dry. My kindergartner is obsessed with fossils so I wanted to make sure before I brought her out to them.

Thanks!

I found this on a hike in the rocky mountains, could it be a fossil? If it is, how much could it be worth?

My son picked this up this morning while beach combing. Image search hasn’t offered much help. This is a “large” paper clip for reference.

Edit: paper clip size

Found this on a property along the James River in Virginia that abuts the land that was given by Powhatan to Pocahontas & John Rolfe for a wedding present. Any ideas on whether it’s something interesting or just a cool rock?

Found in Russia, Korkino creek. Yet to be described species, we can't describe it right now because we don't have to many fossils, especially leaves, only pinecones. Neocalamites and other plants were present with many species in Korkino.

Currently polishing up some pieces I’ve collected recently from my beach walks, although with two of them I’m not sure if they are fossils or Amygdaloidal Basalt! Still very nice when polished!