''Gaviella'' is an alleged

North American North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Ca ...

Paleogene gaviiform which the holotype (and only known specimen) consists of the proximal end of a left

carpometacarpus The carpometacarpus is a bone found in the hands of birds. It results from the fusion of the carpal and metacarpal bone, and is essentially a single fused bone between the wrist and the knuckles. It is a smallish bone in most birds, generally flat ...

from

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

, United States. However, Shufeldt mentioned the location and the age of the fossil was not recorded by J.B. Hatcher and his team who collected it. Shufeldt originally classified this taxon as a species of the living genus '' Gavia'' being half the size of the

common loon The common loon or great northern diver (''Gavia immer'') is a large member of the loon, or diver, family of birds. Breeding adults have a plumage that includes a broad black head and neck with a greenish, purplish, or bluish sheen, blackish ...

(''Gavia immer'') due to some similarity of the carpometacarpus of the aforementioned extant species. In 1940 Wetmore argued the specimen is distinctive enough to, not only belong to its own genus which named ''Gaviella'', but also felt they belong to their own subfamily Gaviellinae. This lead him to believe the specimen originated from the

White River Formation The White River Formation is a geologic formation of the Paleogene Period, in the northern Great Plains and central Rocky Mountains, within the United States. It has been found in northeastern Colorado, Dawes County in western Nebraska, Badlands ...

References

Gaviiformes Prehistoric bird genera {{paleo-bird-stub