HADROSAURIDAE, Cope, 1869

Carpenter, Kenneth, 1982, Baby dinosaurs from the Late Cretaceous Lance and Hell Creek formations and a description of a new species of theropod, Contributions to Geology, University of Wyoming 20, pp. 123-134 : 131

Family HADROSAURIDAE

Fig. 9

Material: Teeth: UCM 45060 (UCMP-V5711) H 3.6 mm, W 3 mm; and UCM 45061 (UCMP-V5711) H 2.9 mm, W 3 mm.

Discussion: The teeth show heavy usage wear ( Fig. 9 ); a similar condition was noted by Horner and Makela (1979) for baby hadrosaurs recovered from the Two Medicine Formation. It has been standard procedure to assign all isolated hadrosaur teeth from the Lance and Hell Creek formations to Edmontosaurus (= Anatosaurus ); however, there may be yet another genus of hadrosaur in the Lancian (M. Brett-Surman, personal communication).

Figures

Figures 1-11. Fig. 1, Dromaeosauridae, tooth, UCM 39502. Fig. 2a-h, Sauromithoides inequalis: 20,, buccal view of hatchling left dentary, UCM 41666; c, lingual view; e, dorsal view; b, buccal view of left dentary, NMC 8540 (cast); d, lingual view; f, dorsal view; g, lateral view of hatchling basioccipital, UCM 43218; and h, ventral view. Fig. 3a-c, teeth of Pectinodon bakkeri: a, holotype, UCM 38445; b, paratype, UCM 38446; and c, paratype, UCMP 73098. Fig. 4, Pararıychodon lacustris, tooth, UCMP 124990. Fig. 5a, b, Tyrannosauridae: a as lateral view of UCMP 119853; and b, posterior view. Fig. 6, Theropoda, tooth, UCMP 124987. Fig. 7a, b, tooth of Aublysodon mirandus: a! lateral view of UCMP 124406; and b, posterior view. Fig. 8, Thescelosaurus sp., tooth, UCMP 124973. Fig. 9, Hadrosauridae, tooth, UCM 45060. Fig. 10, Ceratopsidae, tooth, UCM 45057. Fig. 11, Ankylosaurus magniventris, tooth, UCMP 124399. Heavy bars to left of specimens = 2 mm.