Complex sentence: Walrus ivory carving and engraving has been an important folk art for people of the Arctic since prehistoric times, among them the Inuit (Inupiaq and Yupik) of Greenland and North America and the Chukchi and Koryak of Russia.
Split into simpler sentences: Walrus ivory carving and engraving has been an important folk art for people of the Arctic since prehistoric times. The Inuit (Inupiaq and Yupik) of Greenland and North America and the Chukchi and Koryak of Russia.