Paronychodon lacustris, Cope, 1876Compsemys imbricarius, Cope ED, 1876

Cope ED, 1876, Descriptions of some vertebrate remains from the Fort Union beds of Montana, Proceedings of the Academy of Natural Sciences of Philadelphia 28, pp. 248-261 : 256-257

Paronychodon lacustris , gen. et sp. nov.

Char. Gen. - The teeth which characterize this genus have the general character of those of Plesiosaurus , Elasmosaurus , etc. The crowns are subconic, and the enamel is thrown into longitudinial plicae. The special characters of the genus are seen in the form of the crown, one side of which is convex, and the other side plane, so that the section instead of being circular is seimicircular. It is also strongly curved in the direction of its plane face.

Char. Specif. - Both anterior and posterior edges are curved, and are not acute nor denticulate. There are four plicae on the flat face, only two of which approach the apex. There are six keels on the convex face, all of which approach the apex. All the carinae are rather obtuse, and the enamel is otherwise smooth. The apex is very acute.

Compsemys imbricarius , sp. nov.

This species, like the others of the genus, has the scutal sutures well defined, and the superficial surface of the carapace sculptured. The character of this sculptuire distinguishes the species, and in the present instance in a special mainnier. It consists, in the C. imbricarius , of excavations bounded on the sides by a short ridge each, which alterniate with each otlher. Tllus each bounding ridge terminates abrluptly at the fuindus of one of the fosse, while the other end of the fossa rises and contracts to another ridge. The result is precisely that seen in the interior sculpture of Saracenic dlomes or nichles, anid is olle whichi is quiite unique among tortoises. The direction of the ridges is, at right angles to the costal dermal sutures. This species was about as large as the snapping tortoise ( Chelydra serpentina ).

Compsemys imbricarius , sp. nov.

This species, like the others of the genus, has the scutal sutures well defined, and the superficial surface of the carapace sculptured. The character of this sculptuire distinguishes the species, and in the present instance in a special mainnier. It consists, in the C. imbricarius , of excavations bounded on the sides by a short ridge each, which alterniate with each otlher. Tllus each bounding ridge terminates abrluptly at the fuindus of one of the fosse, while the other end of the fossa rises and contracts to another ridge. The result is precisely that seen in the interior sculpture of Saracenic dlomes or nichles, anid is olle whichi is quiite unique among tortoises. The direction of the ridges is, at right angles to the costal dermal sutures. This species was about as large as the snapping tortoise ( Chelydra serpentina ).