After Young & de Andrade, 2009, with some taxon information from “Paleofile.com” (2005)

Geosaurus Cuvier, 1824
        Lacerta von Sömmerring, 1816
        Halilimnosaurus Ritgen, 1826
        Mosasaurus Holl., 1829
        Rhacheosaurus Meyer, 1830
        Brachytaenius von Meyer, 1842

        †Geosaurus giganteus (Sömmerring, 1816) Cuvier, 1824
            Lacerta giganteus von Sömmerring, 1816
            Lacerta (Geosaurus) gigantea (von Sömmerring); Cuvier, 1824
            Halilimnosaurus crocodiloides Ritgen, 1826
            Mosasaurus Bavaricus Holl., 1829
            Geosaurus Sömmerringii von Meyer, 1831
            Brachytaenius perennis von Meyer, 1842
            Geosaurus giganteus von Quenstedt, 1852 [just. emend.]
            Geosaurus Sömmerringi von Meyer, 1859 [just. emend.]
            Mosasaurus giganteus Cope, 1869

        †Geosaurus lapparenti (Deblemas & Strannoloubsky, 1957)
            Dakosaurus lapparenti Deblemas & Strannoloubsky, 1957

        †Geosaurus grandis (Wagner, 1858)
            Cricosaurus grandis Wagner, 1858
            Cricosaurus medius Wagner, 1858

        †G. sp.
            Nusplingen Geosaurus, SMNS 81834



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