A 2016 study by Chris Stringer found "Homo heidelbergensis" to have not been the common ancestor of Neanderthals and humans, being instead placed entirely on the Neanderthal side of the tree along with Denisovans (close relatives of the Neanderthals) and the Steinheim skull, which was classified as an early Neanderthal fossil. Taking this into account, the LCA of modern humans and Neanderthals needs to be dated even further back, e. g. to "Homo erectus", see Neanderthal §Evolution. Sequencing of genome (aDNA) and proteome (ancient protein) of further human fossils has to be done in order to shed light on the relation of "H. heidelbergensis" and the Steinheim skull to the pre-neanderthal "Neandersovans", the proposed LCA of Neanderthals and Denisovans.