Meiolania
| Meiolania Temporal range: Oligocene–Holocene |
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| Meiolania platyceps skeleton, American Museum of Natural History | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Testudines |
| Suborder: | Cryptodira |
| Family: | †Meiolaniidae |
| Genus: | †Meiolania Owen, 1886 |
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Meiolania ("small roamer") is an extinct genus of cryptodire turtle from the Oligocene to Holocene, with the last relict populations at New Caledonia which survived until 2,000 years ago.
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[edit] Description
Meiolania had an unusually shaped skull that sported many knob-like and horn-like protrusions. Two large horns faced sideways, giving the skull a total width of 60 centimetres (2.0 ft), and would have prevented the animal fully withdrawing its head into its shell. The tail was protected by armored 'rings', and sported thorn-like spikes at the end.[1] The body form of Meiolania may be viewed as having converged towards those of dinosaurian ankylosaurids and xenarthran glyptodonts.
The animal was rather large, measuring 2.5 metres (8.2 ft) in length, making it the second-largest known nonmarine turtle or tortoise, surpassed only by Colossochelys atlas from Asia, which lived in the Pleistocene. It lived in Australia and New Caledonia.
The Meiolania specimens which were once living on New Caledonia and Lord Howe Island were much smaller than their giant relatives from the Australian continent.
[edit] Classification
Its surviving relatives are the cryptodire turtles of South America.
[edit] Behaviour
Meiolania turtles fed on plants. Because the remains known by 1925 were found close to beaches, it was thought to be aquatic. It is now known to have been terrestrial.
[edit] Discovery and species
The genus was erected in 1886 based on remains found on Lord Howe Island, which Richard Owen assigned to the two species M. platyceps and M. minor (now a synonym of the latter).[2] These were the first good meiolaniid remains, and were used to show that the first known remains of a related animal, a species from Queensland now known as Ninjemys oweni (which was assigned to Meiolania until 1992), did not belong to lizards as initially thought, but to turtles.[3] Woodward sunk Niolamia argentina into Meiolania, but this was not accepted by later authors.
M. mackayi was described from Walpole Island in 1925. It was smaller and less robust than M. platyceps.[4]
M. brevicollis was described in 1992 from the Camfield Beds of northern Australia, and differed from M. platyceps in having a flatter skull and other horn proportions.[5]
[edit] Extinction
Remains of a Meiolania species, named Meiolania damelipi, have also been found on the island of Efate in Vanuatu, associated with settlements from the Lapita culture. It is thought that it was hunted to extinction by the Lapita people.[6] [7]
[edit] See also
[edit] References
- ^ Palmer, D., ed (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 67. ISBN 1-84028-152-9.
- ^ http://www.archive.org/details/philtrans02369205
- ^ http://www.biodiversitylibrary.org/pdf3/005970900084521.pdf
- ^ Anderson, C. (1925). "Notes on the extinct Chelonian Meiolania, with a record of a new occurrence". Records of the Australian Museum 14 (4): 223–242. doi:10.3853/j.0067-1975.14.1925.844.
- ^ Megirian, D. (1992). "Meiolania brevicollissp. Nov. (Testudines: Meiolaniidae): A new horned turtle from the Australian Miocene". Alcheringa: an Australasian Journal of Palaeontology 16 (2): 93–10. doi:10.1080/03115519208619035.
- ^ White, A. W.; Worthy, T. H.; Hawkins, S.; Bedford, S.; Spriggs, M. (2010-08-16). "Megafaunal meiolaniid horned turtles survived until early human settlement in Vanuatu, Southwest Pacific". Proc. Natl. Acad. Sci. USA 107 (35): 15512–15516. doi:10.1073/pnas.1005780107. http://www.pnas.org/content/107/35/15512.short. Retrieved 2011-08-30.
- ^ Keim, Brandon (2010-08-17). "Extinct, King Koopa-Style Giant Turtle Found on Pacific Island". Wired. http://www.wired.com/wiredscience/2010/08/last-giant-land-turtle/. (Popular presentation of some material from the PNAS article)
- Barry Cox, Colin Harrison, R.J.G. Savage, and Brian Gardiner. (1999): The Simon & Schuster Encyclopedia of Dinosaurs and Prehistoric Creatures: A Visual Who's Who of Prehistoric Life. Simon & Schuster.
[edit] External links
- Meiolania platyceps Owen (The Australian Museum; photo)
- Mikko's Phylogeny Archive on Cryptodira
