Boreodon matutinus, Lambe, 1902

Lambe L. M., 1902, New genera and species from the Belly River Series (mid-Cretaceous), Geological Survey of Canada Contributions to Canadian Palaeontology 3, pp. 25-81 : 79

Boreodon matutinus . Sp. nov.

Plate XV., fig. 15 .

This early type of mammal is represented by a single tooth, a premolar, having two, slightly divergent roots. The crown is in the form of a laterally compressed cone, somewhat rounded above, angular in front, evenly rounded behind, with a well defined, undulating cingulum encircling its base. A slight lateral concavity, more clearly defined within, occurs in each side of the tooth near the base of the crown in line with the cleft between the roots. The cingulum is angular and pl'ominent at either end, becoming rounded and broader on the sides. The crown is considerably worn on the inner side of its apex. One root only remains and it is imperfect below.

Figures

PLATE XV. Fig. 1. Ornithomimus altus, Lambe, caudal vertebra, superior view, natural size. Page 52. Fig. 2. View of right side of same. Fig. 3. Ornithomimus altus, caudal vertebra, superior view natural size. Page 52. Fig. LL. The same, inferior view. Fig. 5. The same, right side. Fig (S. Ornithomimus altus, left sidc of lumhar vertebra of small individual natural size. Fig. 7. The same, superior view. Fig. S. The same, anterior view. Fig. Ü. Terminal phalanx of megalosauroid dinosaur, lateral view; natural size. Fig. 10. The same, proximal view. z, prezygapophysis i, postzygapoplıysis; s, neural spine e, transverse process. Fig, ll. Tooth of Deinorloıı cnrplanatus‘, Cope, side view; four times the natural size. Page 45). Fig. 12. Transverse section of the same. Fig. 13. Ptilodus primaevus, Lambe, right man libular rztmus,c.\' ternal view; enlarged four times. Page 79. Fig. 1 -1. The same, internal view. pflf, fourtli prernolar; mf, first molar i, socket for incisor; n, socket for second molar. Fig. 15. Boreodon matutinus, Lambe, premolar. side view, four times natural size. Page TQ c, cingulum. Fig. 16. Right maxillary bone, (provisionally associated with Scapherpelnu tectmn), external view, four times thc natural size. Fig. ii. Inferior' view of the samc, similarly cnlargcd. Page 32. Fig. is. Prcınaxillary bone of Diphyodus longirostris, Lambe, inferior view; enlarged four times. Page 30. Fig. 19. Transverse section of samc, similarly enlarged. t, tooth-base m, interspace.