The discoveries were announced by the Pompeii Archaeological Park on August 7.
Collagen extracted from the mammoth bones places this site 36,250 and 38,900 years ago.
Two settlements – a stone fortress, and other buildings – were found on what was once the border of ancient Adiabene.
The treasures were handed over to Mexico’s consulate in Portland, Oregon, by the U.S. Customs and Border Protection Office.
It would have been one of the most ornamented heavy swords of the period.
Although six are believed to have been built, only two have ever been discovered before.
The game was known as Pitz or Pok-a-Tok and was played by players hitting the ball with their elbows, knees or hips.
The species – named Chemnitzion richteri – used an ambush strategy to feed, according to researchers in Germany.
The archaeological find was briefly visible at low spring tides and is now covered once more as the shifting sands move again.