The first claim about these bones was called "Moab man". Apparently they were native american burials dated to about 210-280 years ago, and the bones are not fossilized, but stained with copper solutions. After "Moab man" was discredited, they took the same bones, plus some others found in the same area and called them "Malachite man". The bones were buried in soft sediment, not in the solid rock of the Dakota formation which is 90-115 million years old. The creationists try to claim that they are cretaceous fossils of humans. The original claims go back to at least 1975. Kind of amusing that they keep presenting it as real evidence.
(CC110 and CC111 in The Counter Creationism Handbook by Mark Isaak.
