Lin, thanks! People only ever talk about Monstera, I didn't even know there were other ones. Having seen your plant go from solid to splits, I trust your opinion that mine is something else. Looking at pics, I'm inclined to think you are right, and came across this which looks so similar to my plant too:
http://www.exoticrainforest.co...
According to what I read and saw in pics, either of these can achieve splits like M. deliciosa. Fascinating.