>>28324673I think Dragon/Steel would work for an Ankylosaurus desgin-wise, but I could also see Fighting with a club-tail.
However, I cannot picture many fighting moves that would focus on a quadrupedal Pokemon. The only one I can really see is Superpower (Brick Break if we're being generous).
It could go bipedal for it's other forms, but then the emphasis on it's tail is lost.
Steel on the other hand has many moves that are rather vague in implementation, such as Gyro Ball and Heavy Slam. Iron Head seems spot on here, but again this is all opinion.