I think that Magolor and Hyness are the same species for many reasons:
Magolor and Hyness' ears are both shaped the same way, they both wear masks, and Magolor could be a pig-like creature because we've never seen Magolor without his mask.
Both know a lot about the ancients and Hyness is an ancient. Magolor could be a descendant of the ancients.
Both of them have yellow eyes.
I know that Hyness and Magolor are shaped differently. But it could be the case where Magolor would have to be older in order to look like Hyness. But it's just a theory so... yeah