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Dromaeosaurus albertensis

Dromaeosaurus albertensis

Matthew & Brown, 1922

GBIF:188004699

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ABOUT

Descriptions(3)

Figure 9 I
Sahni, Ashok (1972): The vertebrate Fauna of the Judith River formation, Montana. Bulletin of the American Museum of Natural History 147 (6): 319-416, DOI: 10.5281/zenodo.3382461, Hdl: http://hdl.handle.net/2246/1099
Dromaeosaurus albertensis is a small carnivorous dinosaur described from the " Belly River Formation " of Alberta by Matthew and Brown (1922, p. 383). These authors stated that the length of the skull is one-third to one-fourth the linear size of that of Deinodon, and differs from it by " reduced number of teeth, the large premaxillary teeth and the unsymmetric form of the maxillary teeth as well as the light skull construction, large fenestrae and numerous details that might be largely associated with its small size. " Teeth similar to those of Dromaeosaurus have been reported and figured (Russell, 1935, fig. 9) from the Milk River Formation of Alberta. They have also been reported from the Judith River Formation (Matthew and Brown, 1922, p. 378). AMNH 8516 is referable to the genus (fig. 9 I). The teeth are usually smaller versions of those of Deinodon, with relatively strongly convex anterior borders. Serrations on the posterior edge of most teeth are coarser than those on the anterior, and in some specimens the anterior crest may be completely unserrated.
Sahni, Ashok (1972): The vertebrate Fauna of the Judith River formation, Montana. Bulletin of the American Museum of Natural History 147 (6): 319-416, DOI: 10.5281/zenodo.3382461, Hdl: http://hdl.handle.net/2246/1099
Dromaeosaurus albertensis MATTHEW AND BROWN, 1922, p. 383. Laelaps explanatus COPE, 1876 a, p. 249. Laelapsfalculus Cope, 1876 a, p. 249. Laelaps laevifrons COPE, 1876 b, p. 344.
Sahni, Ashok (1972): The vertebrate Fauna of the Judith River formation, Montana. Bulletin of the American Museum of Natural History 147 (6): 319-416, DOI: 10.5281/zenodo.3382461, Hdl: http://hdl.handle.net/2246/1099

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AnimaliaChordataReptiliaDinosauriaDromaeosauridaeDromaeosaurusDromaeosaurus albertensis

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FIG. 9. A, B. Edmontonia lorngiceps, AMNH 8543, lateral views of an isolated tooth, x 1. C, D. Palaeoscincus costatus, AMNH 8542, lateral views of an isolated tooth, x 12. E, F. Thescelosaurus cf. T. neglectus, AMNH 8536, lateral views of an isolated tooth, x 10. G, H. Ceratopsidae, AMNH 8540, lateral views of an unworn tooth, x 12. I. Dromaeosaurus albertensis, AMNH 8516, lateral view of an isolated tooth, x 12. J, K. Paronychodon lacustris, AMNH 98523, lateral views of an isolated tooth, x 12. L, M. Troodon formosus, AMNH 8518, lateral ~~~~~~~~~~~~~~~~~~~~~~~~~~~~3. views of an isolated tooth, x 12. N. 0,?Stegoceras validus, AMNH 8530, lateral views of an isolated tooth, x 1-. Dinosaur egg shell fragments. P. AMNH 8545, external view of shell (Class B). Q. Internal view. Both x 10. R. AMNH 8546, external view of shell (Class B). S. Internal view. Both x 10. T. AMNH 8548, external view of shell (Class C). U. Internal view. Both x 10. V. AMNH 8547, external view of shell (Class B). W. In- ternal view. Both x 10. X. AMNH 8544, external view of shell (Class A), x 10.

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Source Information

The vertebrate Fauna of the Judith River formation, Montana

checklist

This dataset contains the digitized treatments in Plazi based on the original journal article Sahni, Ashok (1972): The vertebrate Fauna of the Judith River formation, Montana. Bulletin of the American Museum of Natural History 147 (6): 319-416, DOI: 10.5281/zenodo.3382461, Hdl: http://hdl.handle.net/2246/1099

GEOLOGIC INVESTIGATION of the Late Cretaceous Judith River Formation in the area just north of the Judith River on the Missouri River in north-central Montana has resulted in the discovery of varied vertebrate forms. The beds are mainly freshwater continental deposits consisting of crossbedded channel sandstones, gray siltstones, and carbonaceous shales with occasional seams of lignitic coal. The stratigraphic sequence consists of the Marias River Shale overlain by the Eagle, Claggett, Judith River, and Bearpaw formations. The last four constitute the Montana Group. The Judith River Formation is Campanian in age as determined by its position between the fossiliferous marine Claggett and Bearpaw shales.

The fauna was obtained from the upper 50 feet of the formation. The bone concentration in the productive sandstone is the result of size sorting leading to underrepresentation of the larger dinosaurs. Three orders of mammals are represented, the Eutheria by a single genus, the Allotheria by five, and the Metatheria by at least three genera. Teiid and parasaniwid lizards are frequent. Only a fraction of the large number of described dinosaur genera, however, is represented in the collection by isolated teeth. Fish and amphibians form a sizable portion of the fauna.

Vertebrates from the Judith River Formation are more primitive than, but generally similar to, later Maestrichtian species. The mammals differ from their descendants in the Lance Formation at the species level. The community structure and the paleoecology of the fauna of the Judith River Formation resemble those of the Lance Formation. The greatest difference between the two communities is the greater variety of dinosaurs in the earlier formation.

Sahni A, plazi (1972). The vertebrate Fauna of the Judith River formation, Montana. Plazi.org taxonomic treatments database. Checklist dataset https://doi.org/10.5281/zenodo.3382461 accessed via GBIF.org on 2026-06-16.

CC0Published 12/31/1972View dataset
GBIF Usage Key
188004699
Dataset Key
fd03f669-c046-46cd-861a-6bf56b7fc989
Origin
source
Backbone Key
4966352
Taxon ID
1A7187CFFFC01777FF27FD67E05152CC.taxon
Last Crawled
6/10/2026
Last Interpreted
6/10/2026
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