Answer:
Homo neanderthalensis and Homo Sapiens idaltu. Beyond physical differences, it’s difficult to say how Neanderthals differed from modern humans. The clues we do have come from their genome. The ancient hominins shared about 99.7 percent of their genetic material with us, meaning they were mostly human in this regard. How the rest differed is largely unclear, though we do have some ideas. The fossil record is incomplete. Of the small proportion of organisms preserved as fossils, only a tiny fraction have been recovered and studied by paleontologists. In some cases the succession of forms over time has been reconstructed in detail.