Fig. 141.—Teeth of Iguanodon.
a, young tooth; b, c, teeth further advanced, and worn.
(Wealden.)
The teeth ([Fig. 141]), which are the most important and characteristic organs of the whole animal, are imbedded laterally in grooves, or sockets, in the dentary bone; there are three or four sockets of successional teeth on the inner side of the base of the old teeth. The place thus occupied by the edges of the teeth, their trenchant and saw-like form, their mode of curvature, the points where they become broader or narrower which turn them into a species of nippers or scissors—are all suitable for cutting and tearing the tough vegetable substances which are also found among the remains buried with this colossal reptile, a restoration of which is represented in [Plate XXI.], p. 296.
Fig. 142.—Fishes of the Cretaceous period.
1, Beryx Lewesiensis; 2, Osmeroides Mantelli.
The Cretaceous seas contained great numbers of Fishes, among which some were remarkable for their strange forms. The Beryx Lewesiensis (1), and the Osmeroides Mantelli (2) ([Fig. 142]), are restorations of these two species as they are supposed to have been in life. The Odontaspis is a new genus of Fishes which may be mentioned. Ammonites rostratus ([Fig. 140]), and Exogyra conica ([Fig. 147]), are common shells in the Upper Greensand.