Ancestor Vessels from Nigeria

I have two clay pots that I really like. I never really knew much about them and just started to find some information on them because Kim Sack Gallery has one of them and has a label to go with it.
At Kim Sack Gallery (here in Johannesburg) the piece is labelled as "Jungur Culture - Nigeria / Chad - Wiiso vessel". From this thanks to the internet I found that they are Ancestor Vessels.
The Primitive Gallery in the Us has some good photos of the many ancestor vessels they have. They place them as being from the Mambila People in Cameroon.

 Anyway here are my two little guys as they stand in my garden.(That's my photo of the day)