The study analyzed the genetic samples of 37 wild orangutans from populations across Sumatra and Borneo and conducted a morphological analysis of the skeletons of 34 adult males.

[3] The holotype of the species is the complete skeleton of an adult male from Batang Toru who died after being wounded by locals in November 2013.

[10] Orangutans were able to travel from Sumatra to Borneo because the islands were connected by land bridges as parts of Sundaland during recent glacial periods when sea levels were much lower.

[4] Dominant male Tapanuli orangutans have prominent moustaches and large flat cheek pads, known as flanges, covered in downy hair.

[15] Tapanuli orangutans live in tropical and subtropical moist broadleaf forests located south of Lake Toba in Sumatra.

[3] It is listed as critically endangered by the International Union for Conservation of Nature (IUCN) because of hunting, conflict with humans, the illegal wildlife trade, rampant habitat destruction for small scale agriculture, mining and a proposed hydroelectric dam, the Batang Toru hydropower project, in the area with the highest density of orangutans, which could impact up to 10% of its already dwindling habitat and degrade important wildlife corridors.

[3] In August 2019 Swiss environmental group PanEco, which is a partner in the Sumatran Orangutan Conservation Programme, dropped its previous opposition to the dam, several months after firing several researchers who opposed the new strategy.