Newly discovered monkey species from Congo (Image from Wikimedia commons, enhanced by Ai)Deep inside the dense forests of the Democratic Republic of Congo, scientists have discovered a monkey that had remained unknown to science for years.The newly identified species, named Colobus congoensis, is an all-black monkey with one striking feature: a distinct orange patch around its mouth. Researchers have now confirmed that it is a separate species from its closest known relative, the black colobus monkey.Interestingly, this discovery began with a photograph taken nearly two decades ago.A photograph that sparked a mysteryIn 2008, a photographer captured a partial image of a dark-coloured monkey high in the forest canopy, with its dark coat and part of its tail taking up most of the photo. Since the animal had its back to the camera, the picture did not reveal much. (A & B) C. congoensis, Lomami National Park, Democratic Republic of Congo. Photo credits: (A) Daniel Rosengren, (B) Bravo Bofenda. (C & D) C. satanas, Lope National Park, Gabon. Photo credits: (C) Martin Royele/Royele Safaris, (D) Barna TakatsHowever, the image was enough to make the researchers curious, who later returned to the dense, closed-canopy forests between 2018 and 2022, to investigate further. Over the course, they recorded dozens of sightings and carefully documented the animal’s appearance and behaviour.Besides the unusual orange colouring around its mouth, monkey’s deep, distinctive roars also stood out. When they compared their skulls with those of black colobus monkey (Colobus satanas) — to rule out any corelation — there was a notable difference: the newly studied monkey was much smaller.Also Read | The hidden animal mystery inside a 1611 painting has finally been solvedGenetic testing eventually provided the answer.Story continues below this adThe researchers found that the monkey belonged to a distinct evolutionary lineage that had diverged from C. satanas at least four million years ago. Their findings, published in PLOS ONE on July 15, formally establish Colobus congoensis as a new species.A new species that may already be at riskDiscovering a new primate is unusual. Scientists say such discoveries are increasingly associated with remote, challenging and understudied regions.The newly described monkey was already known to some local communities by the name Likweli, although researchers do not know when the name was first given to it.The excitement of discovering a new species, however, comes with a concern: Colobus congoensis may already be vulnerable.Story continues below this adThe monkey is hunted for meat and appears to have a relatively small habitat of only about 1,700 square kilometres. Scientists say more research is needed to understand how many of these monkeys remain and the threats they face.Protecting its forest habitat will also be crucial, with researchers stressing the importance of working with local communities to safeguard the newly recognised species.In other words, this may be a new species to science, but the forests of Congo have long known about this unusual monkey, which seems to be under threat already.