This 1 3/4 inch incised-on-bone depiction of a mammoth or mastadon ( at least 13,000 years old, since that's when they went extinct) found in Florida struck me as a modern fake.
Why? The linear overlapping in the legs. This drawing convention is fairly sophisticated, not even present in Egyptian heiroglyphs.
But some of the cave paintings at Lascaux show it, though more crudely, so I could be wrong.
Herzog's new documentary on those cave paintings sounds like it's actually worth trekking to see it in 3-D.