The Chelydridae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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

s that has seven extinct and two extant

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

. The extant genera are the snapping turtles, ''

Chelydra ''Chelydra'' is one of the two extant taxon, extant genus, genera of the snapping turtle family, Chelydridae, the other being ''Macrochelys'', the much larger alligator snapping turtle. The snapping turtles are native to the Americas, with ''Che ...

'' and '' Macrochelys''. Both are

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the

Western Hemisphere The Western Hemisphere is the half of the planet Earth that lies west of the Prime Meridian (which crosses Greenwich, London, United Kingdom) and east of the 180th meridian.- The other half is called the Eastern Hemisphere. Geopolitically, ...

. The extinct genera are '' Acherontemys'', '' Chelydrops'', '' Chelydropsis'', '' Emarginachelys'', '' Macrocephalochelys'', '' Planiplastron'', and '' Protochelydra''.

Fossil history

The Chelydridae have a long

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

history, with

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

species reported from North America as well as all over Asia and Europe, far outside their present range. The earliest described chelydrid is '' Emarginachelys cretacea'', known from well-preserved fossils from the

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

stage of the Late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

. Another well-preserved fossil chelydrid is the Late

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

'' Protochelydra zangerli'' from

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

. The

carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...

of ''P. zangerli'' is higher-domed than that of the recent ''Chelydra'', a trait conjectured to be associated with the coexistence of large, turtle-eating

crocodilia Crocodilia () is an order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorph pseudosuchia ...

ns. Another genus, ''Chelydropsis'', contains several well-known

Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...

n chelydrid

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

that existed from the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

to the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58C. acutirostris'') only occupy the northwestern corner of the continent, reflecting their recent arrival from Central America as part of the

Great American Interchange The Great American Biotic Interchange (commonly abbreviated as GABI), also known as the Great American Interchange and the Great American Faunal Interchange, was an important late Cenozoic paleozoogeographic biotic interchange event in which land ...

Gallery

Common Snapping Turtle Close Up.jpg,

Common snapping turtle The common snapping turtle (''Chelydra serpentina'') is a species of large freshwater turtle in the Family (biology), family Chelydridae. Its natural range extends from southeastern Canada, southwest to the edge of the Rocky Mountains, as far eas ...

at Taum Sauk Mountain State Park Submerged Snapping turtle.jpg, Two-year-old captive-raised snapping turtle from

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

Snapping turtlewithcan.jpg, Female next to can to show size Alligator Snapping Turtle Skeleton.jpg, Skeleton of alligator snapping turtle at the

Museum of Osteology The Museum of Osteology, located in Oklahoma City, U.S., is a private museum devoted to the study of bones and skeletons (osteology). The museum displays over 450 skeletons of animal species from all over the world. With another 7,000 specimens a ...

20230613 mamma snapping turtle PD27362.jpg, Female snapping turtle laying eggs (not visible), Pleasant Valley Wildlife Sanctuary,

Lenox, Massachusetts Lenox is a town in Berkshire County, Massachusetts, United States. The town is in Western Massachusetts and part of the Pittsfield, Massachusetts, Pittsfield Metropolitan Statistical Area. The population was 5,095 at the 2020 United States census ...

20230613 snapping turtle laying eggs.jpg, Female laying eggs

References

External links

* * {{Taxonbar , from=Q650212 Extant Maastrichtian first appearances Turtle families Symbols of New York (state) Taxa named by John Edward Gray

Fossil history

Gallery

See also

References

Further reading

External links