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Wannaganosuchus
''Wannaganosuchus'' (meaning "Wannagan crocodile", in reference to the Wannagan Creek site where it was discovered) is an extinct genus of small alligatorid crocodylian. It was found in Late Paleocene-age rocks of Billings County, North Dakota, United States.
==History and description==
''Wannaganosuchus'' is based on SMM P76.28.247, a mostly complete skull and postcranial skeleton missing some vertebrae, coracoids, part of the feet, ribs, and other pieces. A few small bony scutes are also assigned to the genus, but not to the type specimen. SMM P76.28.247 was found semi-articulated in the lower part of the Bullion Creek Formation, near the base of a lignitic clay layer deposited in a marsh setting on a floodplain. ''Wannaganosuchus'' was named in 1982 by Bruce R. Erickson. The type species is ''W. brachymanus''; the specific name means "short forefoot".
The skull of SMM P76.28.247 was low, without elevated rims over the eyes, and was long. The snout was short and pointed compared to Cretaceous alligatorids. Its premaxillae (the bones of the tip of the snout) had five teeth each, while the maxillae (main tooth-bearing bones of the upper jaw) had thirteen teeth each, with the fourth being the largest and the last three having broad flattened crowns. The lower jaws had twenty teeth on each side, and like the upper jaws, the last five had broad crushing crowns. The forelimbs were short (hence the specific name), and the hindlimbs were long in comparison. The scutes were extensive. Most of the scutes were keeled, but did not have spikes.〔
Erickson regarded ''Wannaganosuchus'' as a generalized early alligatorid closer to the line leading to modern alligatorids than other more specialized early alligatorids.〔 It may be the same as ''Allognathosuchus''.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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