My guess is a demasoni mutt with another african, not the convict. I had a female pull the same trick with a Ps. Ruarwe when the male demasoni died. Hybrid babies looked like demasoni (except white bands less bright) but 2-3x the size of the other demasoni!!
They made good pets, but I kept them out of my demasoni breeding population when they got their own tank.
Either way, they look great, and now you've got more. Enjoy them!!