Homo sapiens is a biological classification. On biological grounds (DNA), humans and chimpanzees belong to the same genus, just as horses and asses, which are less closely related, belong to the same genus. This means that, on biological grounds, Pan troglodytes and Pan paniscus are more accurately classified as Homo troglodytes and Homo paniscus.
It follows from this that all human ancestors since the split with chimpanzees are also of the same genus. This means that, on biological grounds, Australopithecus Afarensis, Australopithecus Africanus, etc. are more accurately classified as Homo Afarensis, Homo Africanus, etc.
By the same token, since Homo sapiens sapiens successfully interbred with Homo neanderthalensis, on biological grounds, Neanderthals belong to the same species as Homo sapiens, and are more accurately classified as Homo sapiens neanderthalensis.