The Bili apes
Reports of giant, lion-killing 'mystery apes' in the Bili forest of the Democratic Republic of Congo, possibly gorilla-chimp hybrids, turned out to be an unusual population of eastern chimpanzees.
2003 CE · 4.10, 24.75 · status: explained
The account
Photographer Karl Ammann, visiting in 1996 to look for gorillas, brought back a skull, a photograph and footprint casts; later accounts of local 'lion killer' apes that seldom climbed trees fuelled sensational press stories. A 2003 National Geographic report noted that the apes nested on the ground like gorillas but had the diet and features of chimpanzees.
The sceptical view
A cryptid resolved by science: mitochondrial DNA (2003, 2006) and long-term fieldwork showed eastern chimpanzees, part of a large continuous population across northern Congo, with some unusual behaviours such as ground nesting.