Hello, now, apologies for the photos. They're the best the seller can get, I'm afraid. But hopefully they are ok to get some sort of ID/confirmation.
He has a selection of Hell Creek teeth. They are all very small--ranging from below 1cm to just above 1cm in length.
1 - Troodontid -- not the clearest image, but they seem to have distinctive denticles which are common in troodontid teeth? I don't think Troodon is from Hell Creek, but I see online it says Troodontid teeth have been found there. Seller has a more precise location of Harding County, South Dakota for these.
2 - Sold as possible Richardoestia -- Again, not the best of pictures. But hopefully it's enough to get an idea. To me, these look like they're more than likely a reptile tooth?
3 - Unknown, possibly a raptor? Again, not the best image, but hopefully it's enough.
Many thanks--and sorry for the poor pics. Even if exact species can't be confirmed, any ideas or possibilities would be, as always, much appreciated