Notes on Mesozoic vertebrate fossils Author Marsh, O. C. text American Journal of Science 1892 1892-05-31 260 171 176 journal article 10.5281/zenodo.2838842 7ea885fa-a128-4dff-accd-c3d234a97859 2838842 Palaeoscincus, Leidy, 1856 . A new reptilian genus and species, Palaeoscincus costatus , was proposed by Dr. Leidy in 1856 for a single tooth found by Dr. Hayden in the Judith Basin. This tooth was more fully described and figured by Leidy in 1859 .* The specimen showed well-marked characters, and many similar teeth have since been found, both in the Judith Basin and in various other localities of the Laramie. A smaller species, apparently of the same genus, is not uncommon in the Ceratops beds of Wyoming, and a characteristic tooth is shown on Plate III, figure 3 . This may be taken as the type specimen, and the species it represents may he called Palaeoscincus latus . The crown of the tooth in this species is broader and the apex more pointed than in the first species described, and this is clearly shown in comparing the present figures on Plate III with those given by Leidy. * Proc. Acad. Nat. Sci. Philadelphia, p. 72, 1856; and Trans. Amer. Phil. Soc., p. 146, pl. ix, figs. 49-52, 1859. The tooth from the Laramie described by Cope in 1882 as a mammalian premolar and as the type of the generic name Meniscoessus evidently belongs to the above or an allied genus, and all three are unquestionably the teeth of Dinosaurian reptiles pertaining to the order Stegosauria . On Plate IV, figure 1 , a very small but typical tooth of Stegosaurus from the Jurassic is represented. The allied genus Diracodon , also Jurassic, has similar teeth.