Archaeopteryx suggested that "Archaeopteryx" was a dinosaur that was no more closely related to birds than were other dinosaur groups. Kurzanov (1987) suggested that "Avimimus" was more likely to be the ancestor of all birds than "Archaeopteryx". Barsbold (1983) and Zweers and Van den Berge (1997) noted that many maniraptoran lineages are extremely birdlike, and they suggested that different groups of birds may have descended from different dinosaur ancestors. The discovery of the closely related "Xiaotingia" in 2011 led to new phylogenetic analyses that suggested that "Archaeopteryx" is a deinonychosaur rather than an avialan, and therefore, not a "bird" under most
Archaeopteryx are limited to a sort of "proto-down" not dissimilar to that found in the dinosaur "Sinosauropteryx": decomposed and fluffy, and possibly even appearing more like fur than feathers in life (although not in their microscopic structure). These occur on the remainder of the body—although some feathers did not fossilize and others were obliterated during preparation, leaving bare patches on specimens—and the lower neck. There is no indication of feathering on the upper neck and head. While these conceivably may have been nude, this may still be an artefact of preservation. It appears that most "Archaeopteryx" specimens became embedded in anoxic