Ichthyosaur tooth - Kiamichi shale

Plesiosaur tooth?  From the Kiamichi Shale, Benbrook, Texas. 

First question would be the age of the specimen. Kiamichi Shale being a member of the Fredericksburg Group makes it Albian in age, during which time both ichthyosaurs and plesiosaurs were still around. However, going off of the plicidentine enamel folds on the tooth, I'd say this clearly is an ichthyosaur tooth. Plesiosaurs (sensu lato, thence including pliosaurs) have much sharper/crisper striations. Great find!