A previously unknown species of African monkey has recently been discovered in the rainforests of the Democratic Republic of Congo. Named Colobus congoensis, the monkey is believed to have diverged from its closest known relative four to five million years ago, making it one of the oldest evolutionary splits within its lineage.

Colobus congoensis, colloquially “Likweli,” has an unusually small range for its genus and is being proposed to be classified as endangered. “The discovery of Colobus congoensis is reshaping our understanding of African monkey evolution,” said FAU’s Kate Detwiler, who was a member of the scientific team. “[It] is both a scientific triumph and a sobering reminder that some of Earth’s rarest creatures may vanish before the world even knows they exist.”

• Kate Detwiler