I am stealing these pictures from another forum, but I did come up with this technique independently.
A training partner and I were messing around before class, talking about the gogoplata and kind of poking fun at it. I had the absurd idea to try it from the mounted position.
It seemed retarded at the time, and though maybe technically valid it was just too strange to consider. And then one random day a few weeks or months after that, I was rolling with a new student and almost literally fell right into it. Messed around with the setup for it, and came to actually like it.
I came across someone else who had posted the idea just a few weeks ago, and was like "hey fucker, you stole my idea." Either way, he has pictures and I don't, so I will use them.