.....the unit's team encountered 13 bipedal chimpanzees that were attempting to kill another animal. Standing 4.5-5 ft high, they were uniformly grey in colour, but by far their most distinctive feature was the series of spines running down each chimp's back, which stood up like porcupine quills whenever the chimps became agitated.
Coudray also stated that the team actually shot a three-minute video film of these extraordinary apes, but that it remains a military secret. The precise location of this sighting is unknown, but as the team was from the US Navy and the Democratic Congo is virtually landlocked, it may have been somewhere close to Lake Tanganyika.