Lepidotus OCCIDENTALIS

Leidy, J., 1860, Extinct vertebrata from the Judith River and Great Lignite formations of Nebraska., Transactions of the American Philosophical Society 11, pp. 139-154 : 149

Lepidotus OCCIDENTALIS .

The genus of ganoid fishes Lepidotus , appears to have come into existence during the Liassic period, to have extended through the Oolitic, Wealdean, and Cretaceous periods, and to have become extinct in the Eocene Tertiary period.

As if to keep up the association, in the manner that Dr. Mantell found together in the Wealdean deposits the remains of Iguanodon , Megalosaurus , Crocodilus , and Lepidotus , Dr. Hayden discovered with the remains of Trachodon , Deinodon , and Crocodilus , a half dozen ganoid fish scales , which appear to belong to the genus Lepidotus . The specimens may indicate two species, but with equal probability they may appertain to a single one.

Four of the scales, (as represented in figures 20, 21, plate 11 ,) are lozenge-shaped, with their root prolonged from one side in the direction of the longest diameter of the lozenge. Two of the scales, (as represented in figures 22, 23 ,) are square, with their root projecting from one of the longer sides. All the specimens are invested with thick, shining, enamelled substance; and one of the square scales exhibits on its free surface, parallel square lines of growth.

The largest lozenge-like scale has the sides of its free or enamel surface about 4 lines long; and the smallest has two of the sides 3 lines long, the other sides 2 lines long. The larger square scale has its long sides 5 lines, and its short sides 3 1/2 lines.

Explanation of Figures, Plate 11.

Figures 20—23. Scales of Lepidotus occidentalis , of the natural size.

Figures

1-3. Trionyx foveatus 4.Emys obscurus 5-7. Compsemys victus. 9-19 Crocodilus humilis. 20-23. Lepidotus occidentalis. 24-30 Mylognathus priscus