Protoradjia insularis was first described from Sumatra, Indonesia in 1995 with distribution records in Singapore as well. The specific epithet “insularis” refers to the Riau and Singapore islands where the paratypes were collected from. It is most easily distinguished from other species by its frontal shield clearly bending over the vertex.
In the forest, this species is commonly found both in the leaf litter and on fallen logs. Although it is quite commonly found in the wild, its care has not been well determined and historically, they have not been doing very well in captivity.
