Very unusual black and white set - Mammoth Ivory?

A bit of a mystery set, both in terms of country of origin, material and age. This was a surprise when it turned up - a purportedly plastic set, which turned out to be an ivory of some kind, with the black side made of a dense wood. When compared to my elephant ivory sets, this looks significantly different in angles of the Schreger lines. Measuring angles leads me to the conclusion that this set may indeed be made from mammoth ivory - though to be conclusive would require carbon dating or DNA sequencing (neither of which are within financial reach).