The Canadian field-naturalist (1923) (20492983056)

Drawing of Corythosaurus excavatus skull

Title: The Canadian field-naturalist

Identifier: canadianfieldnat1923otta (find matches)

Year: 1923 (1920s)

Authors: Ottawa Field-Naturalists' Club

Subjects:

Publisher: Ottawa, Ottawa Field-Naturalists' Club

Contributing Library: Harvard University, Museum of Comparative Zoology, Ernst Mayr Library

Digitizing Sponsor: Harvard University, Museum of Comparative Zoology, Ernst Mayr Library

Text Appearing Before Image:

46 The Canadian Field-Naturalist (Vol. XXXVII A NEW SPECIES OF CORYTHOSAURUS WITH NOTES ON OTHER BELLY RIVER DINOSAURIA By CHARLES W. GILMORE Associate Curator of Paleontology United States National Museum, Washington, D.C. HE University of Alberta has in its collection of vertebrate fossils from the Red Deer River localities in Alberta several specimens which are here des- cribed as contributing to a better understanding of the skeletal anatomy of the genera to which they pertain. In addition to the new species herein described, other specimens furnished information of such interest that it should be made available to students of the dinosaurian Reptilia. I take pleasure in acknowledging my in- debtedness to Dr. J. A. Allan for the privilege of studying these specimens, and also for making it possible for me to undertake this work. A New Species of Crested Dinosaur. A partially prepared skull clearly referable to the genus Corythosaurus exhibits characters that appear to indicate its specific distinctness from the single known species, C. casuarius Brown, and the name Corythosaurus excavatus is therefore proposed for its reception. This specimen is of further interest as elucidating th ecranial structure, and it fully confirms Lambe's conclusions^ regard- 1 Memoir 120, Geol. Siirvey of Canada, No. 102, Geol. Ser., 1920, pp. 70-76.

Text Appearing After Image:

ing the homologies of certain bones in the skull of the crested hadrosaurs. Corythosaurus excavatus, new species. Plate 1, fig. 1. Type: Catalogue number 13, University of Alberta; consists of the greater portion of a well preserved skull, but lacking the maxillary, lachry- mal, jugal, quadratojugal and quadrate bones. Collected by George F. Sternberg, 1920. Type Locality: Sand creek, Red Deer river, Alberta, Canada. Horizon: Belly River formation. Upper Cretaceous. The genus Corythosaurus now contains two species which may be distinguished by skull characters as follows: Corythosaurus casuarius Brown. Posterior border of crest regularly convex; greatest height of crest above center of orbit; premaxillary (prefrontal of authors) in contact at posterior extremity with nasal. Corythosaurus excavatus, new species. Posterior border of crest angularly concave, greatest height of crest posterior to orbit; pre- maxillary widely separated at posterior end from nasal. The skull upon which the latter species is based has not been fully prepared at this time, the left side still remaining in the burlap-plaster covering as originally received from the field. From Mr. Sternberg's field notes it is learned that the left side is slightly more incomplete than the right, but, with the exception of the loss of bones enumerated above, the skull is in an excellent state of preservation. The crest in Corythosaurus exca^ vatus, as here interpreted, is formed Fig. 1.—Lateral view of the skull oi Corythosaurus excavatus. Cat. No. 13, Univ. of Alberta. Type. exo. exoccipital; na. nasal; o. orbit; prf. pre-frontal; pmx. premaxillary; po. postorbital; sq. squamosal; stf. supratemporal fossa. About one-seventh natural size.

corythosaurus illustrations of vertebrata fossils the canadian field naturalist 1923 canada internet archive anatomical atlas anatomical illustration

1923

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