Big-headed turtle

A big-headed turtle (Platysternon megacephalum)
Conservation status
Critically Endangered (IUCN 3.1)^[1]
CITES Appendix I (CITES)^[2]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Cryptodira
Superfamily:	Testudinoidea
Family:	Platysternidae Gray, 1869^[3]
Genus:	Platysternon Gray, 1831^[3]
Species:	P. megacephalum
Binomial name
*Platysternon megacephalum* Gray, 1831^[3]
Synonyms^[4]
Platysternon megacephalum megacephalum Platysternon megacephalum Gray, 1831 Platisternon megacephalus Gray, 1834 Platysternon megacephalus Gray, 1835 Emys megacephala Schlegel, 1838 Platysternon magacephalum Fitzinger, 1843 (ex errore) Platysternum megacephalum Boulenger, 1889 Platysternon platycephalum Mertens, 1959 (ex errore) Platysternum megalocephalum Stanek, 1959 (ex errore) Platysternon megacephalum megacephalum Wermuth, 1960 Platysternon magacephalum megacephalum Pritchard, 1979 Platysternon megacephalum tristernalis Schleich & Gruber, 1984 Platysternon megacephalum tristornalis Alderton, 1988 (ex errore) Platysternon megacephalum peguense Platysternon peguense Gray, 1870 Platysternon megacephalum peguense Wermuth, 1960 Platysternon megacephalum vogeli Wermuth, 1969 Platysternon megacephalum penguense Nutaphand, 1979 (ex errore) Platysternon megacephalum penuense Nutaphand, 1979 (ex errore) Platysternon megacephalum peguensis Sharma, 1998 (ex errore) Platysternon megacephalum shiui Platysternon megacephalum shiui Ernst & McCord, 1987

The big-headed turtle (Platysternon megacephalum) is a species of turtle in the family Platysternidae from Southeast Asia and southern China.^[3]

Background

Previously considered a distinct family placed on occasion in "Kinosternoidea", it was later moved to the Emydidae. This, as well as the subfamily and the genus Platysternon, are monotypic.

The big-headed turtle is named after its unproportionally large head which leads to an inability to retreat into its shell. In order to protect itself it instead has an armored head and sharp beak.^[5]

Distribution

The big-headed turtle is found in Cambodia, China, Laos, Myanmar, Thailand, and Vietnam.^[1]^[3] It is commonly found in fast flowing streams and waterfalls in rocky areas. [1]

Behaviour

The big-headed turtle is known to readily climb over obstacles in and around rivers and fast streams, using its tail as a prop to extend the reach of its strong claws. It also uses its beak to assist in climbing.^[6] It has been reported to climb trees and bushes. These turtles generally move more during the night, and are not prone to moving long distances. They have a general daily range of 0-89.6m and males tend to move further than the females in this species.^[7] They are not strong swimmers, and when swimming, this species occasionally arches its tail in the manner of a scorpion.^[6] The big-headed turtle cannot pull its head in its shell. That being the case, it will not hesitate to use its powerful jaws to defend itself. Its diet consists of fish, snails and worms.^[8] It also tends to eat fruits like the Machilus spp., as well as insects, crabs and mollusks.^[9]

Exploitation

The big-headed turtle is found quite frequently in illegal wildlife trade.^[5] It is readily consumed in Asia and is frequently a market item. Hunters capture them on lines with baited straight pins, so this species is rapidly disappearing in the wild.^[10] The species is also threatened by its use in the pet trade.^[1]

Subspecies

P. m. megacephalum, China, 1831^[3]
P. m. peguense, Myanmar and Thailand, 1870^[3]
P. m. shiui, Cambodia, Laos and Vietnam, 1987^[3]

In addition, two other subspecies, P. m. tristernalis (1984) and P. m. vogeli (1969), have been given, but may be invalid.^[11]

References

External links

Testudines

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Subclass: Anapsida
Order: Testudines

Genus

Chelonioidea
(Sea turtles)

Cheloniidae	†Allopleuron Caretta †Carolinochelys Chelonia †Eochelone Eretmochelys †Gigantatypus †Glarichelys †Itilochelys Lepidochelys †Mexichelys †Miocaretta Natator †Pacifichelys †Syllomus †Tasbacka
Dermochelyidae	†Arabemys †Bouliachelys †Corsochelys †Cosmochelys Dermochelys †Eosphargis †Mesodermochelys †Psephophorus
	†Alienochelys †Berruchelus †Euclastes †Peritresius †Procolpochelys †Protosphargis †Puppigerus

Kinosternoidea

Dermatemydidae	Dermatemys
Kinosternidae	Claudius †Hoplochelys Kinosternon Staurotypus Sternotherus

Testudinoidea

Emydidae	Chrysemys Clemmys Deirochelys Emys Actinemys Emydoidea Glyptemys Graptemys Malaclemys Pseudemys Terrapene Trachemys
Geoemydidae	Batagur †Banhxeochelys Cuora Cyclemys Geoclemys Geoemyda Hardella Heosemys Leucocephalon Malayemys Mauremys Melanochelys Morenia Notochelys Orlitia Pangshura Rhinoclemmys Sacalia Siebenrockiella Vijayachelys
Platysternidae	Platysternon
Tortoises	Aldabrachelys Astrochelys Centrochelys Chelonoidis Chersina Cylindraspis Geochelone Gopherus †Hadrianus †Hesperotestudo Homopus Indotestudo Kinixys Malacochersus Manouria †Megalochelys Psammobates Pyxis †Solitudo Stigmochelys †Stylemys Testudo

Trionychia

Carettochelyidae	†Allaeochelys †Anosteira Carettochelys
Trionychidae	Amyda Apalone †Axestemys Chitra Cyclanorbis Cycloderma †Drazinderetes Dogania †Gilmoremys †Hutchemys †Khunnuchelys Lissemys Nilssonia Palea †Palaeoamyda Pelochelys Pelodiscus Rafetus Trionyx
	†Basilochelys †Sinaspideretes

†Baenoidea

†Baenidae	†Arvinachelys †Baena †Cedrobaena †Chisternon †Denazinemys †Gamerabaena †Neurankylus †Palatobaena †Peckemys †Plesiobaena
†Pleurosternidae	†Dinochelys †Dorsetochelys †Glyptops †Pleurosternon †Selenemys

Chelydridae	†Acherontemys Chelydra †Chelydrops †Chelydropsis †Emarginachelys †Macrocephalochelys Macrochelys †Planiplastron †Protochelydra
†Eurysternidae	†Achelonia †Chelonides †Eurysternum †Hydropelta †Idiochelys †Palaeomedusa †Parachelys
†Macrobaenidae	†Anatolemys †Aurorachelys †Kirgizemys †Osteopygis †Yakemys
†Nanhsiungchelyidae	†Anomalochelys †Basilemys †Jiangxichelys
†Protostegidae	†Archelon †Atlantochelys †Atlantochelys †Calcarichelys †Cratochelone †Desmatochelys †Iserosaurus †Notochelone †Ocepechelon †Pneumatoarthrus †Protostega †Rhinochelys †Santanachelys †Terlinguachelys
†Sinemydidae	†Jeholochelys †Liaochelys †Manchurochelys †Ordosemys †Sinemys
†Thalassemydidae	†Neusticemys †Palaeomedusa †Thalassemys
	†Adocus †Angolachelys †Argillochelys †Bashuchelys †Brodiechelys †Ctenochelys †Compsemys †Hoyasemys †Larachelus †Leyvachelys †Plesiochelys †Prionochelys †Toxochelys †Uluops †Xinjiangchelys

Pleurodira

†Araripemydidae	†Araripemys
†Bothremydidae	†Araiochelys †Arenila †Azabbaremys †Bothremys †Cearachelys †Chedighaii †Chupacabrachelys †Eotaphrosphys †Foxemys †Galianemys †Ilatardia †Inaechelys †Itapecuruemys †Jainemys †Kinkonychelys †Kurmademys †Labrostochelys †Nigeremys †Phosphatochelys †Polysternon †Puentemys †Rosasia †Rhothonemys †Sankuchemys †Taphrosphys †Ummulisani †Zolhafah
Chelidae	Acanthochelys Chelodina Chelus Elseya Elusor Emydura Hydromedusa †Lomalatachelys Mesoclemmys Myuchelys Phrynops Platemys †Prochelidella Pseudemydura Rheodytes Rhinemys †Yaminuechelys
Pelomedusidae	Pelomedusa Pelusios
Podocnemididae	†Albertwoodemys †Bauruemys †Brontochelys †Caninemys †Carbonemys †Cerrejonemys †Cordichelys Erymnochelys †Lapparentemys †Latentemys Peltocephalus Podocnemis †Stupendemys
†Sahonachelyidae	†Sahonachelys †Sokatra

	†Caribemys †Caririemys †Chubutemys †Hispaniachelys †Tacuarembemys

Phylogenetic arrangement of turtles based on Turtles of the World 2017 Update: Annotated Checklist and Atlas of Taxonomy, Synonymy, Distribution, and Conservation Status. † = extinct.

See also List of Testudines families

Taxon identifiers

Taxon identifiers
Platysternon	Wikidata: Q14566127 Wikispecies: Platysternon BOLD: 81756 CoL: 6S5H EoL: 41194 Fossilworks: 67317 GBIF: 2441883 iNaturalist: 39687 IRMNG: 1201606 ITIS: 208658 NCBI: 55543
Platysternon megacephalum	Wikidata: Q754035 Wikispecies: Platysternon megacephalum ADW: Platysternon ARKive: platysternon-megacephalum BOLD: 81757 CoL: 4JZ39 EoL: 791024 Fossilworks: 253397 GBIF: 2441884 iNaturalist: 39688 IRMNG: 11422864 ITIS: 551846 IUCN: 17585 NCBI: 55544 RD: megacephalum Species+: 8391