sentences:  Semliki harpoon
  
  The Semliki harpoon, also known as the Katanda harpoon, refers to a group of complex barbed harpoon heads carved from bone, which were found at an archaeologic site on the Semliki River in the Democratic Republic of the Congo (formerly Zaire); the artifacts which date back approximately 90,000 years.The initial discovery of the first harpoon head was made in 1988.