This ammonite fossil was a gift from a friend that lives in OK. He found it at a reservoir but I don't remember which one. He said they are common there, all sizes. Gary
Is there two specimens? Second photo looks different.
Photo #1 looks like Eopachydiscus, don't find many small hand held ones.
Found in the "Duck Creek" deposits of N. Texas and S. Okla.
Reservoir was probably Lake Texhoma.
My smallest is just larger than a half dollar.