''Gamerabaena'' is an extinct genus of baenid

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...

which existed in

North Dakota North Dakota () is a U.S. state in the Upper Midwest, named after the indigenous Dakota Sioux. North Dakota is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minnesota to the east, So ...

during the late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

Period. It is known from a single fragmentary skull that was found in the

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval ...

-age

Hell Creek Formation The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of ...

. It contains the species ''Gamerabaena sonsalla''. ''Gamerabaena'' is similar to the genus '' Palatobaena'', but it differs in its lack of a posterior expansion of the triturating (or chewing) surface, a somewhat rectangular skull, and a wide angle between the

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. T ...

e. ''Gamerabaena'' also has a lingual ridge on the inner side of the jaw that is not seen in ''Palatobaena''. ''Gamerabaena'' is considered the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

of ''Palatobaena'' and shares features with both ''Palatobaena'' and '' Plesiobaena''. These features, which include slightly upturned eye sockets, are seen as intermediate between the two other genera. While ''Gamerabaena'' is known only from the skull, it may belong to the same species as ''"Baena" hayi'', which is known primarily from the shell. The genus is named after

Gamera is a fictional monster, or ''kaiju'', originating from a series of Japanese films. Debuting in the 1965 film ''Gamera, the Giant Monster'', the character and the first film were intended to compete with the success of Toho's ''Godzilla'' film ...

, a giant flying, fire-breathing turtle from a series of Japanese

tokusatsu is a Japanese term for live action film or television drama that makes heavy use of practical special effects. ''Tokusatsu'' entertainment mainly refers to science fiction, war, fantasy, or horror media featuring such technology but is som ...

films.

Phylogeny

Cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

after Tyler R. Lyson and Walter G. Joyce (2009).

References

{{Taxonbar, from1=Q20677867, from2=Q5520054 Baenidae Prehistoric turtle genera Late Cretaceous turtles of North America Hell Creek fauna Fossil taxa described in 2010

Phylogeny

See also

References