Siebenrockiella leytensis is a species of freshwater turtle endemic to the Philippines. It is classified as critically endangered. It is locally known as bakoko in Cuyonon.
Philippine forest turtles are readily recognizable by their ginkgo-shaped vertebral scutes and a pale white to yellow line traversing across its head behind the ears. The previous characteristic has earned it the nickname of 'bowtie turtle'.
Philippine forest turtles are classified under the subgenus Panyaenemys. Together with the smiling terrapin (Siebenrockiella crassicollis), it is one of the two species in the genus Siebenrockiella.
Description
left|thumb|S. leytensis has a distinctive pale band of color running across the head just behind the ear openings.
left|thumb|The anterior margin of the carapace of S. leytensis is slightly to strongly serrated.
thumb|The distinctive [[ginkgo-shaped vertebral scutes of the Philippine forest turtle.]]
Philippine forest turtles have brown to reddish brown to black carapaces that reach a length of . Larger individuals can reach in length, though this is relatively rare.
The plastron is reddish brown to black, sometimes with blotches of yellow. In juveniles, the plastron is a uniform yellow.
thumb|Close-up of the head showing the hooked upper jaw.
The upper jaw is hooked and the skin on the sides of the neck and the chin are lighter in color. The lower jaw may also sometimes possess a pair of small yellow spots on the sides.
The legs possess irregular enlarged transverse scales and are darker in color at the front. Four transverse scales are present on the forelimbs and more at the hind limbs (though absent at the heels). All limbs are webbed and possess large claws on all toes.
The Malaysian giant turtle (Orlitia borneensis) and the smiling terrapin (Siebenrockiella crassicollis) are the only other turtle species with ginkgo-shaped vertebral scutes, but they do not possess the white to pale yellow line on the back of their heads.
Formerly classified under the genus Heosemys, it was transferred to the previously monotypic genus Siebenrockiella by Diesmos et al. in 2005 based on morphological and genetic comparison with Siebenrockiella crassicollis. While the specific name means 'from [the island of] Leyte'. An erroneous name, as the turtle is actually from the islands of Palawan and is not found in Leyte.
Ecology and behavior
Philippine forest turtle populations often exist alongside other more common native turtle species, including Asian leaf turtles (Cyclemys dentata) and Southeast Asian box turtles (Cuora amboinensis).