Cimoliasaurus magnus, Leidy, 1852

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 : 32-33

Cimoliasaurus magnus , Leidy.

Cimoliasaurus magnus , Leidy. 1852. Proc. Acad. Nat. Sci. Philadel., vol. v, p. 325, and ibid, 1854 vol. vii, p. J 2, pi. II, figs. 4-6 .

Cimoliasaurus magnus , Leidy. 1865. Cretaceous Reptiles of the United States, p. 25, pi. v, figs 13-19 and pi. vi, (Smithsonian Contr. to Knowledge, vol. xiv).

Fourteen cervical vertebrae, found within a limited space and probably belonging to one individual, are referred to this species; they form a tolerably complete series with a gradual increase in size from front to back.

These vertebrae agree with those of the type species in form but are smaller.

The centra may be described as shorter than broad, with concave sides and lower surface, articular faces ellipsoidal, sligthly concave with angular margins, costal facet placed low on the sides. Neural arches in all the specimens, broken off, except in one, apparently a late cervical, in which the basal part on one side is preserved, shov,ung the height of the neural canal. The bases of the ribs still remain in a few cases. In the supposed late cervical, the costal facet extends upward on to the base of the neural arch. Two large foramina, placed one on either side of the median line of the lower surface and separated by a low ridge, are connected with a passage that opens into the neural canal by two separate apertures. The neural canal is about as high as it is wide.

A small vertebra from anterior end of series:	M.
Length of centrum	-045
Breadth of articular face	-065
Height of same	-040
Width of neural canal	-012
A larger vertebra from posterior end of series
Length of centrum	-044
Breadth of articular face	-072
Height of articular face	-045
Width of neural canal	-015
Height of costal face	-025
Breadth of same	-022

According to Cope, Discosaurus is specifically identical with this genus. "Whilst under the generic name Cimoliasaurus, Lydekker * has included Brimosaurus, Leidy , and Elasmosaurus and Polycotylus of Cope.

Belly River series, Red Deer river, below Berry creek, 1898 and 1901.

Figures

Fig. 4 Plastron of Adocus variolosus one-sixth the natural size. ;

Fig. 5 Uppper or inner surface of the same plastron, from Red Deer river, Alberta.

Fig. 6. Anterior half of the shell of Adocus variolosun, from Red Deer river; ventral aspect showing the front margin of the carapace, One-fifth natural size

FIG. 13. -Stereocephalus tutus. Dermal plate from Red Deer river one - sixth the natural size. A, side view; B, view from above. Provisionally associated with S. tutus.)

FIG. 14.-—Head of Monoclonius dawsoni, from a sketch in the field; uııe-uvelftlı the natural size. p, parietal or, orbit; oc, occipital condyle q, qnadrate m, maxilla (inner side, showing a row of foramina; h, horn core s, squamosal.

FIG. 15. --Posterior crest of Monoclonius dawsoni, viewed from beneath; slightly less than one-eighth natural size. The numbers give the thickness of the bone, in centimetres, at the points indicated. P, parietal S, squaniosal F, fontanelle.

FIG. 16.-—Sacrum provisionally associated with Monoclonius dawsoni, less than one-seventh the natural size 2 superior view.

FIG. 17.-Tlıe same sacrum right lateral aspect; about one-seventli the natural size, a, a, facet for iliiiui d, diapophysis; np. neural platform: ns, neural spine i, intcrspace .

FIG. 18. Monoclonius canadensis part of the skull from the right lateral aspect: one-eighth natural size. fp, postirontal h, horn core o, orbit: sqnztmoszil p, right lateral extension from parietal j, jugal l, lower jaw.

FIG. 19. -:\ 1Anterior dorsal vertebra of Monoclonius canadensis, one-fourth the natural size. A, front view; B, left side view; a, anterior face of ccntrnm d, (lizpopliysis h, facet for head of rib n, neural canal; s, neural spine t, facet for tubercle of rih z,`prezygapophysis z, post- Zygapophysis