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 tail is uniformly light brown in color. Philippine forest turtles are relatively easy to recognize. They can be distinguished from all other turtles by their strongly projecting epiplastra, vertebral scutes shaped like ginkgo leaves, the absence of temporal arches in the skull, and the aforementioned light lines behind its head. 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. Taxonomy and nomenclature The scientific name of Philippine forest turtles is Siebenrockiella leytensis. It is classified under the genus Siebenrockiella in the subgenus Panyaenemys (frequently misspelled as "Panayanemys" and "Panyanemys"). It belongs to the subfamily Geoemydinae of the family Geoemydidae. 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. The subgenus name is derived after the Pala'wan word panya-en. The word was used by a local Palawan resident to describe the turtles in a 2003 survey. The word means 'enchanted', supposedly because Philippine forest turtles were favorite pets of the forest spirits. -emys comes from the Greek word εμύς, meaning 'freshwater turtle'. The generic name was coined in honor of the Austrian zoologist Friedrich Siebenrock. 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. History of discovery Philippine forest turtles were first described by the American herpetologist Edward Harrison Taylor in 1920 as Heosemys leytensis. He described them on the basis of two specimens (male and female) collected by Gregorio Lopez, allegedly from the swamps of the municipality of Cabalian in Southern Leyte (now known as the municipality of San Juan). These specimens were unfortunately destroyed in World War II during the firebombing of Manila. No other specimens were reported until 1988 when a specimen was bought from