It’s been a very busy weekend, so this will be a very short post. today I simply want to introduce the latest mystery fossil. This is a bizarre little fossil, measuring less than 2 cm across. It’s not the best picture, I admit, but there is enough resolution to identify it to at least the Order. I will post a clue a day until Friday, when I will reveal its identity. Good luck, take a guess, and have fun.
Tuesday’s clue: These teeth are used to eat animals much, much smaller than the animal it came from.
Wednesday’s clue: We are very popular at many aquariums.
Thursday’s clue: Some people say i have wings, but I do not fly. I may have a cold heart, but I don’t bite.
paleoaerie 
Sorry I’m responding so late on this, but is that a ray tooth?
No problem, and in fact it has given me the opportunity to correct a mistake I posted earlier about this fossil. It is indeed a ray tooth. Specifically, I believe it is a piece of a tooth plate from an Aetobatis, an eagle ray that (probably) lived in Arkansas (while not officially reported from Arkansas, it has been found in nearby states and other rays from the same family have been found in the state) during the Eocene through Miocene. I had stated earlier that they were filter feeders, which is not correct. While manta rays are filter feeders, most smaller rays, such as Aetobatis and Myliobatis, another common ray in the area, were durophagous like their modern relatives, meaning they ate shelled animals like clams. crabs and shrimp.
Very cool- thanks for the update! Enjoying your posts.
Thanks! I’m glad you like them. Also glad you took the time to comment. Comments are most welcome.