Watermelon seed oil is extracted by pressing from the seeds of the Citrullus lanatus (watermelon). It is particularly common in West Africa, where it is also called ootanga oil. The common watermelon most likely originated almost 5,000 years ago in the Kalahari Desert of Africa where botanists have found its wild ancestors, known as the Kalahari Melon, still growing. Watermelons migrated north through Egypt, and during the Roman era they were cultivated and prized. Traditionally, the seeds are extracted from the seed casing, and dried in the sun. Once dried, the seeds are pressed to extract the oil.