Humans today live in what we call a symbolic culture. All the objects around us have a symbolic dimension. The clothes we wear, for instance, send out signals about us that are unrelated to their practical function. We form symbolic relationships where no biological relationship exists, with a husband, sister-in-law, godchild, blood-brother, for example. Language, of course, is another key example, the relationship between the words and the objects and concepts to which they refer is completely arbitrary and that is the essence of a symbol.Of course there is also a symbolic dimension even to the lives of animals. See previous posts about the peacock's tail, and if you argue that growing a tail isn't 'creating' an artefact, what about Bower Birds? And there has been recent research showing that Dolphins call each other by 'name'.
Neanderthals created few symbolic artefacts. Before about 50,000 years ago there is very little evidence of any that stand up to scientific scrutiny.
All work and no play: Why Neanderthals were no Picasso - opinion - 27 February 2013 - New Scientist
Perhaps the use of symbols is not a distinction between Homo Sapiens and Neanderthals, nor even between humans and animals, but characteristic of life. I wonder, could that be in there as the, one of the, defining features of a living organism?