Mature males have a spur on the forward-facing sides of the tibiae of the first pair of legs and a pear-shaped palpal bulb with a wide, curved embolus.

[5] The nomenclature of a group of theraphosid genera from South and Southeast Asia, including Cyriopagopus, Haplopelma, Lampropelma, Omothymus, and Phormingochilus, is somewhat confused.

[2] This analysis is accepted by the World Spider Catalog as of March 2017[update], with the comment that "Haplopelma, Cyriopagopus, Melopoeus, and other ornithoctonine genera are in urgent need of revision".

[1] The genus is found in Southeast Asia (China, Myanmar, Thailand, Cambodia, Vietnam, Malaysia, and Singapore), Borneo, and the Philippines.

Species that have been studied live in underground, silk-lined tubes, often with a surrounding web of radiating signal threads.

[8] The large fangs can produce puncture wounds which are susceptible to bacterial infection if not treated properly.