In the Riddle of the Great Beings, the Iron Wolves were introduced into the canon, and they even got an official representation, but we still don't know exactly what were they before. But also it was mentioned in the RotGB, that the Wasteland Wolves looks very similar to the Iron Wolves, see the quote below:
"Tarduk doubted it. He had spotted one of their pursuers. It looked a little like one of the wasteland wolves that lived in the desert. Their paws had evolved to be able to traverse across the loosest sand and they were highly effective trackers. But, Tarduk reminded himself, though it looked like one, their stalker wasn't one of those creatures. For one thing, this beast was half made of metal. Tarduk had never seen anything like it."
So my question would be, that were, for say a pack of Wasteland Wolves modified to become the first Iron Wolves? It would make sense, seeing that it was said, that the Great Beings modified existing creatures to make the Iron Wolves, as well as Tarduk at first misinterpretended the Iron Wolves to the Wasteland Wolves, so I think it would be a nice touch to "merge" the two species.