Platysternidae belongs to the class Reptilia, the order Testudines, and the suborder Cryptodira.
Platysternidae is a moderately sized turtle with a large head that cannot be retracted into the shell. The carapace and plastron are both large and the species has a long tail.
The family has a single genus and species and can be found in mountainous streams of southeast Asia. The genus is Platysternon and the species is Platysternon megacephalum.
The family Platysternidae is most closely related to snapping turtles, the family Chelydridae, which include Macrochelys temminckii (alligator snapping turtle), Macrochelys suwanniensis (Suwannee snapping turtle), Chelydra rossignonii (Central American snapping turtle), and Chelydra serpentina (common snapping turtle).
Some classifications even place the species found under Platysternidae in Chelydridae however differences in DNA sequences, chromosomes, and skeletal structures show the species and genus needs to be in a separate family.
Platysternidae was once thought to be closely related to the family Emydidae which includes many pond turtles endemic to North America and Central America.
Platysternidae was first described by John Edward Gray, a British zoologist, in 1831.
The family can be easily identified by their big heads. The width of the head is usually about half that of the shell. The large nature of the head means that the turtle cannot withdraw the head into the shell.
Platysternidae can be found in southeastern Asia in Myanmar (formerly known as Burma) and southern China to Thailand. The Platysternidae are found in monotonous regions with elevations of as much as 2,000 meters or 6,600 feet. They are found in cool streams.
There isn’t much known about the behavior of Platysternidae. However, they are most native at twilight and are considered to be nocturnal.
During the day, they generally remain hidden. Members of Platysternidae have nasty bites comparable to that of snapping turtles.
The species are excellent climbers and are known to climb over rocks in the streams they inhabit. They are also known to climb curtains and wire fences.
The Platysternidae may brumate terrestrially, although it is suspected that they brumate within the northern regions of their geographic range.
Platysternidae is known to be a strict carnivore and feeds on invertebrates, amphibians, and fish. The family is known to feed mainly in water but also feed on land when needed.
Platysternidae is known to lay one or two eggs per clutch, although the number of clutches gravid females lay in a year is not known. The females nest from May to August and hatchlings emerge in September.
Species Within The Family Platysternidae
1. Big-headed Turtle
- Scientific Name: Platysternon megacephalum
- Total Body Length: 15.75 inches (40 cm)
- Carapace Length: (15 to 18 cm)
- Lifespan: 15 years (in captivity)
- IUCN Red List Status: Critically Endangered
Platysternon megacephalum can be found in southeastern Asia and is known to be endemic to southern Myanmar (formerly known as Burma) to northern Thailand, Kampuchea in Cambodia, Laos, northern Vietnam, southern China to the east, and Hainan Island which is part of China.
The turtle has a big head and a long tail. This tail is almost as long as the body. The head is too big for the shell and as such the big-head turtle cannot retract its head into its shell. The carapace is depressed and yellowish to brown. While the front of the carapace is rectangular, the back is more rounded. The plastron is yellow.
Males have more concave plastron than females have. Also, juveniles are more brightly colored than adults are.
These turtles can be found in streams and brooks in mountainous regions. These riparian habitats are fast-moving and rocky. These habitats are cascading clearwater streams found at elevations of about 100 to 800 m.
The species can be found in temperatures of 12 to 17 degrees Celsius or 54 to 63 degrees Fahrenheit.
Little is known about the reproduction of P. megacephalum. However, it is known that the species lay a clutch of 1 or two eggs that resemble bird eggs. In recent times, club These eggs have a dimension of 2.2 cm by 3.7 cm.
In captivity, the species is known to live for 50 years in the wild and 15 years in captivity.
Although a widespread species, the big-headed turtle has narrow habitat requirements. This means that they can only be found in specific places. This makes the species difficult to study and survey.
Although, the species is known to be heavily exploited. The population has reduced by at least 90% within the last 90 years or three generation lengths. This decrease in wild populations has led to the species being classified as Critically Endangered in 2018.
P. megacephalum is known to be carnivorous and has strong jaws and beaks. These turtles are known to feed on worms, mollusks, and fish. The species is nocturnal and hunts during the night. They may hunt at the bottom of their riparian habitats or shrubs near the streams they live within.
P. megacephalum is a nocturnal turtle that hides under rocks on land or underwater during the day. During the night, P. megacephalum hunts for food. Although not a capable swimmer, P. megacephalum is a capable climber and can climb rocks with ease.
The big-headed turtle can deliver serious bites when aggravated. It bites down and doesn’t let go. The turtle isn’t known to be aggressive towards other turtle species within the same habitat.
This turtle faces several threats but the main threat is the collection for food markets and the pet trade. The species is known to be popular in southern Chinese food markets. P. megacephalum is also commonly marketed as pets although caring for them in captivity is difficult.
Other threats include habitat degradation due to agriculture and tourism.
The species is included in Appendix I of CITES and Appendix II in China. The species is also protected in all the countries/regions where it is endemic except for Laos and Cambodia.
In Thailand, P. megacephalum is protected under the Wildlife Crime and Protection Act (WARPA). In Myanmar, P. megacephalum is protected under the Protection of Wildlife, Wild Plants, and Conservation of Natural Areas Law. In Hong Kong, P. megacephalum is protected under the Wild Animals Protection Ordinance. In China, P. megacephalum is protected under the Wild Animals Protection Law.
Frequently Asked Questions
Do Platysternidae make good pets?
Platysternidae should not be kept as pets. The species are ill-equipped for life in captivity as they require specific conditions to thrive. These conditions can not be met in captivity. As such, specimens sold into captivity do not receive the needed care.
Can you keep Platysternidae as pets?
You cannot keep Platysternidae as pets. They are almost impossible to care for and ownership of the species is considered illegal.
Are Platysternidae endangered?
Unfortunately, the only species of Platysternidae is critically endangered. This is the Platysternon megacephalum. This species is suspected to have lost over 90% of its wild population over the last 90 years. This decrease is the reason why the species is considered to be endangered.
The Chinese population has suffered from the collection for human consumption as well as for the pet trade. The Hong Kong and Thailand subpopulations are suspected to be stable.
Because of the endangered nature of the turtle, it is protected under law in all regions except in Laos and Cambodia.
Which laws protect Platysternidae?
International laws that protect the Platysternidae include Appendix I of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) and Appendix II in China.
Domestic laws that protect Platysternidae include the Wildlife Crime & Protection Act (WARPA) in Thailand, the Protection of Wildlife, Wild Plants & Conservation of Natural Areas Law in Myanmar, and the Wild Animals Protection Ordinance in Hong Kong, and the Wild Animals Protection Law in China.
What other families is Platysternidae closely related to?
Platysternidae is most closely related to snapping turtles, which is the family Chelydridae.
There are just one species within the family Platysternidae and that is P. megacephalum.
This turtle is known for its huge head which gives it its common name. Platysternidae can be found in southern Asia, in China, Myanmar, Thailand, Cambodia, Laos, and Viet Nam.
They are even found on Hainan Island.
Although the range of the species is large, the conditions required for the species to thrive are limited. This means that they can only be found in very specific habitats. These habitats are rocky swift-flowing streams found within the elevations of 100 m to 800 m in mountainous regions.