''Carbonemys cofrinii'' is an

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 ...

giant podocnemidid

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 ...

known from the Middle Paleocene

Cerrejón Formation The Cerrejón Formation is a geologic formation in Colombia dating back to the Middle-Late Paleocene. It is found in the El Cerrejón sub-basin of the Cesar-Ranchería Basin of La Guajira Department, La Guajira and Cesar Department, Cesar. The fo ...

of the Cesar-Ranchería Basin in northeastern

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

. The formation is dated to approximately 60 to 57 million years ago, beginning about five million years after the KT extinction event.

Discovery and Naming

In 2005, Edwin Cadena, a doctoral student from

North Carolina State University North Carolina State University (NC State, North Carolina State, NC State University, or NCSU) is a public university, public Land-grant university, land-grant research university in Raleigh, North Carolina, United States. Founded in 1887 and p ...

, discovered the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

specimen in the

Cerrejón Cerrejón is a large Coal mining, open-pit coal mine in Northern Colombia owned by Glencore. At Cerrejón, low-ash, low-sulphur bituminous coal from the Cerrejón Formation is excavated. At over the mine is one of the largest of its type, the la ...

coal mine. The genus name, meaning "Coal Turtle," is derived from ''Carbon''" Latin for "coal" and "''emys''" Greek for "freshwater turtle," a reference to the coal mine from which the fossil was extracted. The specific epithet honors Dr. David Cofrin.

Description

The ''Carbonemys'' holotype had a shell that measured approximately , estimated at for a complete

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 ...

. This would place it among the world's largest turtles, tied with the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

'' Peltocephalus maturin'' and

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

Drazinderetes ''Drazinderetes'' is a large bodied genus of Trionychinae, soft shell turtle from the Bartonian, Middle Eocene Drazinda Formation of Pakistan. Its presence in the shallow marine deposits of the Drazinda Formation suggests that ''Drazinderetes'' m ...

'' in carapace length, and exceeded only by the

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 ...

protostegids, the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

'' Stupendemys'', and two Quaternary

testudines 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 ...

('' Megalochelys'' and '' Titanochelon'').

Paleobiology

''Carbonemys''’s relatively massive jaws suggest it possessed a powerful bite. It was likely an omnivore, consuming plants and mollusks, as well as smaller reptiles, which were diverse and abundant in its neotropical freshwater habitat. Its cohabitants included other turtles like the smaller podocnemid '' Cerrejonemys'', giant boid (constrictor) '' Titanoboa'', and crocodylomorphs such as the dyrosaurids '' Cerrejonisuchus'', '' Acherontisuchus'', and '' Anthracosuchus''.

References

† Paleocene turtles Paleocene reptiles of South America Peligran Itaboraian Paleogene Colombia Fossils of Colombia Cerrejón Formation Prehistoric turtle genera Fossil taxa described in 2012 Prehistoric turtles of South America {{Paleo-turtle-stub