Deinodon

Deinodon
Drawing of the Deinodon teeth; Lithograph from 1860.
Temporal occurrence
Upper Cretaceous ( Campanium )
83.6 to 72 million years
Locations
Montana , USA ( Judith River Formation )
Systematics
Dinosaur (dinosauria) Lizard dinosaur (Saurischia) Theropoda Coelurosauria Tyrannosauridae Deinodon
Scientific name
Deinodon
Leidy , 1856
Art
Deinodon horridus  Leidy, 1856

Deinodon ("terrible tooth") is a dubious (dubious) genus of dinosaurs from the group of Tyrannosauridae . The genus is only known from twelve fragmentary teeth that come from the Upper Cretaceous layers of the Judith River Formation in Montana ( USA ). Although no longer used today, the name Deinodon is of great importancein historical research of the Tyrannosauridae (formerly Deinodontidae ) and also found its way into popular culture.

Description and research history

Deinodon was named by the paleontologist Joseph Leidy as early as 1856 , based on teeth discovered by geologist Ferdinand Vandeveer Hayden near the Missouri River in Chouteau County . The type species is Deinodon horridus . It was the first named representative of the Tyrannosauridae. Leidy described Deinodon as a reptile from the Sauria group ; the description consisted of only a few paragraphs. Along with Deinodon , Leidy named three other dinosaurs - Trachodon , Troodon, and Palaeoscincus ; it was the first dinosaur to be named from North America.

The teeth were probably about 5 cm high when complete; thus Deinodon was a smaller representative of the Tyrannosauridae. Leidy noticed that nine of the teeth resemble those of Megalosaurus : They were flattened on the sides, curved like a blade, and had serrated cutting edges. However, the teeth were thicker than those of Megalosaurus . Three other teeth showed a different morphology and were not shaped like blades, but were also attributed to Deinodon by Leidy , as they were found together with the other teeth. Leidy remarks that he would have assigned these tooth types to different genera had they come from different sources.

In 1868, Leidy restricted the genus Deinodon to the nine Megalosaurus -like teeth and placed the three remaining teeth in the new, independent genus Aublysodon . Both Aublysodon and Deinodon were ascribed various other species in the following period; the genera formed the basis of the families Aublysodontidae and Deinodontidae . The Deinodontidae have been assigned to genera such as Albertosaurus , Gorgosaurus , Dryptosaurus and Tyrannosaurus . Both families are no longer used today: The Deinodontidae was abolished in favor of the younger name Tyrannosauridae; at aublysodon and Aublysodontidae it might be to other young tyrannosaurid.

Matthew and Brown already showed that the teeth cannot be distinguished from those of the genus Gorgosaurus . Dale Russell (1970) and various later authors finally declared Deinodon as the noun dubium (dubious name), due to the lack of delimitation from other genera. Ashok Sahni (1972) suggested considering Gorgosaurus as a younger synonym of Deinodon - since the name Deinodon is older, it would have priority according to the International Rules for Zoological Nomenclature ; the name Gorgosaurus would be invalid.

Individual evidence

1. ↑ ^{a b} Thomas R. Holtz Jr .: Tyrannosauroidea. In: David B. Weishampel , Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. 2004, ISBN 0-520-24209-2 , pp. 111-136, here p. 114.
2. ^ ^{A b c d} Peter Dodson: Dinosaurs in America - Joseph Leidy & the Academy of Natural Sciences. In: American Paleontologist. Vol. 17, No. 2, 2009, ISSN  1066-8772 , pp. 32–34, digitized version (PDF; 3.61 MB) ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. . 
3. ^ ^{A b} Donald F. Glut : Dinosaurs. The Encyclopedia. McFarland & Company, Jefferson NC 1997, ISBN 0-89950-917-7 , pp. 334-335: Deinodon.
4. ↑ ^{a b} Joseph Leidy : Notices of remains of extinct reptiles and fishes, discovered by Dr. FV Hayden in the bad lands of the Judith River, Nebraska Territory. In: Proceedings of the Academy of Natural Sciences of Philadelphia. Vol. 8, 1856, ISSN  0097-3157 , pp. 72-73, digitized .
5. ↑ Ralph E. Molnar, Seriozha M. Kurzanov, Zhiming Dong : Carnosauria. In: David B. Weishampel, Peter Dodson, Halszka Osmólska (eds.): The Dinosauria . University of California Press, Berkeley CA et al. 1990, ISBN 0-520-06727-4 , pp. 169-209.
6. ^ ^{A b} William D. Matthew, Barnum Brown : The family Deinodontidae, with notice of a new genus from the Cretaceous of Alberta . In: Bulletin of the American Museum of Natural History. Vol. 46, No. 6, 1922, ISSN  0003-0090 , pp. 367-385, here pp. 374-377, (PDF; 1.8 MB).
7. ↑ Thomas R. Holtz Jr .: The phylogeny and taxonomy of the Tyrannosauridae. In: Darren H. Tanke, Kenneth Carpenter (Eds.): Mesozoic Vertebrate Life. New Research inspired by the Paleontology of Philip J. Currie. Indiana University Press et al., Bloomington IN et al. 2001, ISBN 0-253-33907-3 , pp. 64-83, here p. 67.
8. ↑ Thomas D. Carr: Craniofacial ontogeny in Tyrannosauridae (Dinosauria, Coelurosauria). In: Journal of Vertebrate Paleontology. Vol. 19, No. 3, 1999, ISSN  0272-4634 , pp. 497-520, doi : 10.1080 / 02724634.1999.10011161 .
9. ↑ ^{a b} Ashok Sahni: The vertebrate fauna of the Judith River Formation, Montana. In: Bulletin of the American Museum of Natural History. Vol. 147, Article 6, 1972, ISSN  0003-0090 , pp. 358-359, digitized .
10. ^ Dale A. Russell : Tyrannosaurs from the Late Cretaceous of Western Canada (= Publications in Palaeontology. No. 1, ISSN  0068-8029 ). National Museum of Natural Sciences, Ottawa 1970, p. 3.