The big-headed turtle (''Platysternon megacephalum'') is a species of

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

in the family Platysternidae from

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainlan ...

and southern China.

Background

Previously considered a distinct

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

placed on occasion in " Kinosternoidea", it was later moved to the Emydidae. With the

Geoemydidae The Geoemydidae (formerly known as Bataguridae) are one of the largest and most diverse families in the order Testudines (turtles), with about 70 species. The family includes the Eurasian pond and river turtles and Neotropical wood turtles. Mem ...

being split off from these, it seems wisest to reinstate the Platysternidae. This, as well as the subfamily and the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Platysternon'', are

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

Distribution

The big-headed turtles are found in

Cambodia Cambodia (; also Kampuchea ; km, កម្ពុជា, UNGEGN: ), officially the Kingdom of Cambodia, is a country located in the southern portion of the Indochinese Peninsula in Southeast Asia, spanning an area of , bordered by Thailan ...

, China, Laos,

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

, and

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

Behaviour

Platysternon megacephalum MHNT CHE 1992-19

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.Kirkpatrick, David T. 1995. ''Platysternon megacephalum''. Reptile & Amphibian Magazine, November/December 1995, pages 40 – 47. C/R.
Retrieved 2012-11-25. 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. They are not strong swimmers, and when swimming, this species occasionally arches its tail in the manner of a scorpion. 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. It's diet consists of

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

snails A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastro ...

and

worms Worms may refer to: *Worm, an invertebrate animal with a tube-like body and no limbs Places *Worms, Germany Worms () is a city in Rhineland-Palatinate, Germany, situated on the Upper Rhine about south-southwest of Frankfurt am Main. It had ...

Exploitation

The big-headed turtle 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.James E. Barzy
Turtles in Crisis: The Asian Food Markets
The article itself is not dated, but mostly refers to data in the range 1995-2000. The species is also threatened by its use in the pet trade.

Subspecies

*''P. m. megacephalum'', China, 1831 *''P. m. peguense'', Myanmar and Thailand, 1870 *''P. m. shiui'', Cambodia, Laos and Vietnam, 1987 In addition, two other subspecies, ''P. m. tristernalis'' (1984) and ''P. m. vogeli'' (1969), have been given, but may be invalid.

References

* * Pritchard, D. 1979. Encyclopedia of Turtles. New Jersey: T.F.H. Publications, Inc. Ltd. ;Bibliography * *

External links

* (Chinese

* (Spanish

{{Taxonbar, from1=Q14566127, from2=Q754035 Testudinoidea Turtles of Asia Reptiles of Cambodia Reptiles of China Reptiles of Hong Kong Reptiles of Laos Reptiles of Myanmar Reptiles of Thailand Reptiles of Vietnam Reptiles described in 1831 Taxa named by John Edward Gray Taxonomy articles created by Polbot Critically endangered fauna of China