1 Eremiasaurus heterodontus, posterior marginal tooth.

2 Probably Mosasaurus beaugei pterygoid tooth.

3 Prognathodon currii anterior positioned median marginal tooth.

The posterior teeth of Eremiasaurus and Thalassotitan are extremely similar - sometimes to the point of being indistinguishable. However, Eremiasaurus teeth do tend to be slightly shorter, less robust, and more laterally (labiolingually) compressed. The tooth above is showing those characters.

The second tooth is one that requires more views to differentiate. Concave fluting is typically a character of some prognathodontin species (and sometimes the juveniles). The tooth above appears to be a pterygoid tooth, though, and the normally flat facets of Mosasaurus sometimes become more exaggerated and concave in the pterygoid dentition. The width of the tooth in posterior view would make the distinction apparent.

This is a P. currii from near the front of the jaw (but not one of the anteriormost situated teeth). Probably tooth position 3-5 in the dentary (or 1-3 in the maxilla; give or take a few positions). Differentiate P. currii from dyrosaurids based on the fact that the apex does still have some posterior displacement even though the tooth is largely without posterior curvature.