The conga drum and it's rhythms has it origins in Africa and Cuba and thus, it is Afro-Cuban in origin. The conga is likely a descendant of a one or more African drums, which were brought to Cuba, as well as the Cuban Cajon.
The African predecessors likely include the Makuta, Ngoma, Yuka, Bembé and possibly Ashiko. At least one Cuban predecessor of the conga is the Cuban Cajon (see A History of the Congas Dr. Olavo Alén Rodriguez.)
It does appear that there is more than one drum that influenced the invention and development of the conga. Accordingly, there could also be more drums than what are listed here.