Fossil sceleton of Archelon, a giant Cretaceous turtle

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Classis: Reptilia
Subclassis: Anapsida
Ordo: Testudines
Subordo: Cryptodira
Superfamilia: Chelonioidea
Familia: †Protostegidae
Genus: Archelon
Species: A. ischyros


Archelon Weiland 1896


* Paleobiology Database entry on Archelon Accessed 14 March, 2008

Archelon (Greek meaning ruler turtle) is a genus of extinct sea turtle, the largest that has ever been documented.

Type specimen (YPM 3000) of Archelon ischyros in the Yale Peabody Museum, Yale University

The first specimen of Archelon (YPM 3000) was collected from the Pierre Shale of South Dakota by Dr. G.R. Wieland in 1895 and described by him the following year (Wieland, 1896). The largest Archelon fossil, found in the Pierre Shale of South Dakota in the 1970s, measures more than 4 meters (13.5 feet) long, and about 4.87 meters (16 feet) wide from flipper to flipper. It was a marine turtle, whose closest living relative in the present day is the leatherback sea turtle.[1][2] Archelon's fossils date to around 75-65 million years ago in the Late Cretaceous period[2], when a shallow sea covered most of central North America. Most of the known remains have been found in South Dakota and Wyoming. Though anatomically similar to the earlier species Protostega gigas, it was much larger.[3]


Unlike most modern turtles, Archelon did not have a solid shell, but instead had a skeletal framework supporting a leathery or bony carapace. Other distinguishing features include a pointed tail, a narrow skull, a relatively narrow, high-vaulted shell, and a pronounced overbite.[1] They probably had a very strong bite, and were optimized for feeding on pelagic mollusks such as squid.[4] One theory concerning the one specimen exhibited by the National History Museum in Vienna is that it may have died while brumating on the ocean floor.[4] However, brumation in reptiles is a response to cold weather and it is unlikely that the Western Interior Sea was ever that cold. This same specimen also suggests a century-long life span.[4]

The live weight of an Archelon ischyros is estimated at more than 2,200 kilograms (4,500 pounds)[citation needed].

Popular culture
Mounted cast

An Archelon made an appearance in the Hammer Film Productions 1966 remake of One Million Years B.C.. Archelon also appeared in the Walking with Dinosaurs spinoff special Sea Monsters.

The film The Land Before Time IV: Journey Through the Mists features a helpful, atypically cave-dwelling Archelon, named "Archie", assisting the juvenile sauropod named Littlefoot in the story.

External links

* The Giant Archelon Ischyros


1. ^ a b
2. ^ a b "Archelon". BBC - Science & Nature. Retrieved 2009-05-25.
3. ^ Marine Turtles
4. ^ a b c BHI/Fossils & Minerals/Rept. and Amph./Archelon

Published References:

* Hay, O. P. 1908. The fossil turtles of North America. Carnegie Institution of Washington, Publication No. 75, 568 pp, 113 pl.
* Wieland, G. R. 1896. Archelon ischyros: a new gigantic cryptodire testudinate from the Fort Pierre Cretaceous of South Dakota. American Journal of Science, 4th Series 2(12):399-412, pl. v.
* Wieland, G. R. 1902. Notes on the Cretaceous turtles, Toxochelys and Archelon, with a classification of the marine Testudinata. American Journal of Science, Series 4, 14:95-108, 2 text-figs.
* Wieland, G. R. 1906. The osteology of Protostega, Memoirs of the Carnegie Museum, 2(7):279-305.
* Wieland, G. R. 1909. Revision of the Protostegidae. American Journal of Science, Series 4. 27(158):101-130, pls. ii-iv, 12 text-figs.

Online References:

* Black Hills Institute of Geological Research
* Oceans of Kansas Paleontology

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Source: Wikispecies: All text is available under the terms of the GNU Free Documentation License


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