It's often mentioned that we don't know what Denisovans looked like, because the only fossils we have are little things like finger bones.
It's also often pointed out that we could actually have found plenty of Denisovan fossils; and just not know it. Our concept of what a Denisovan is, is defined by its DNA - we do not have DNA from most fossils. How do we know that we don't already have museums filled with Denisovan remains, but labelled 'Neanderthal' or 'Homo erectus'?
Well, it looks like they've found one. A fossil jawbone found in Tibet in 1980, dated to about 160,000 years ago, may well be from a Denisovan. They did not retrieve any DNA, but the conclusion is based rather on proteins extracted from the bone.
Notably, this is the oldest fossil known from the Tibetan plateau; which is interesting since the genetic adaptations modern Tibetans have to living at high altitude are argued to have been inherited from Denisovans.