Macrobaenidae is an extinct family of turtles, known from the
Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma.
Geology
Pro ...
to
Paleogene
The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...
of
Laurasia
Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pan ...
. Their relationships to other turtles and whether or not they form a monophlyletic group are controversial. They are typically interpreted as stem or
crown group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...
cryptodires
The Cryptodira ('' el, hidden neck'') are a suborder of Testudines that includes most living tortoises and turtles. Cryptodira differ from Pleurodira (side-necked turtles) in that they lower their necks and pull the heads straight back into the ...
, but some more recent analyses have found them to lie outside
crown group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...
Testudines. Macrobaenids can be distinguished from other testudinatans by the presence of a carotid fenestra, cruciform plastron with strap-like epiplastra, and a lack of extragulars.
Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...
Aurorachelys
''Aurorachelys'' is an extinct genus of turtle which existed in Canada (Nunavut) 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 ...
''
Kanguk Formation
The Kanguk Formation is a geological formation in the Northwest Territories and Nunavut, Canada whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; ...
Xiagou Formation
The Xiagou Formation is the middle strata of the Xinminbao Group. It is named for its type site in Xiagou, in the Changma Basin of Gansu Province, northwestern China and is considered Early Cretaceous in age. It is known outside the specialized ...
, China, Early Cretaceous (Aptian)
*''
Kirgizemys
''Kirgizemys'' is an extinct genus of turtle from Early Cretaceous of China, South Korea, Mongolia, Russia and Kyrgyzstan
Kyrgyzstan,, pronounced or the Kyrgyz Republic, is a landlocked country in Central Asia. Kyrgyzstan is bordered b ...
''
Murtoi Formation
The Murtoi Formation is a geologic formation in vicinity of Lake Gusinoye in Russia. It was deposited in the late Barremian to the mid Aptian of the Early Cretaceous. Paleofauna
*'' Kirgizemys dmitrievi''
*'' Tengrisaurus starkovi''
*'' Khurendu ...
Ilek Formation
The Ilek Formation is a Lower Cretaceous geologic formation in Western Siberia. Many different fossils have been recovered from the formation. It overlies the Late Jurassic Tyazhin Formation and underlies the Albian Kiya Formation.
The formation ...
Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...
Geoncheonri Formation
The Geoncheonri Formation () is an Early Cretaceous (Aptian-Albian) geologic Formation (geology), formation of the Hayang Group in the Gyeongsang Basin of southeast South Korea.Judithemys'' North America, Late Cretaceous– Paleocene
*'' Gallica''Paris Basin, France, Paleocene
*'' Macrobaena''Naran Bulak Formation, Mongolia, Paleocene
*''
Osteopygis
''Osteopygis'' is a genus of extinct turtle. ''Osteopygis'', as traditionally seen, is a chimera: the postcrania (including the holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when t ...
'' Late Cretaceous-Paleocene, North America
*'' Oxemys'' Khodzhakul Formation, Uzbekistan, Cenomanian
*''
Yakemys
''Yakemys'' is an extinct genus of macrobaenid turtles from the Late Jurassic-Early Cretaceous (Tithonian-Valanginian?) lower Phu Kradung Formation of Thailand. It is monotypic, containing a single species, ''Yakemys multiporcata''.
Discovery a ...
''
Phu Kradung Formation
The Early Cretaceous Phu Kradung Formation is the lowest member of the Mesozoic Khorat Group which outcrops on the Khorat Plateau in Isan, Thailand. This geological formation consists of micaceous, brown to reddish-brown siltstone beds with minor ...
, Thailand, Early Cretaceous ( Berriasian)
'' Hongkongochelys'' from the Middle-Late Jurassic of China has sometimes been attributed to the family, but other times has been attriuted to Sinemydidae, a group which has an unresolved relationship with Macrobaenidae.