which was situated in the vicinity of the Great Lakes region. The geographers drew an explicit ethnographic distinction between the Sudan region and its analogue Zanj, from the area to their extreme east on the Red Sea coast in the Horn of Africa. In modern-day Ethiopia and Eritrea was Al-Habash or Abyssinia, which was inhabited by the Habash or Abyssinians, who were the forebears of the Habesha. In northern Somalia was Barbara or the Bilad al-Barbar ("Land of the Berbers"), which was inhabited by the Eastern Baribah or Barbaroi, as the ancestors of the Somalis were referred to by medieval Arab and ancient Greek geographers, respectively. In the 19th and 20th centuries, the populations south of the Sahara were divided into three broad ancestral groups: Hamites and Semites in the Horn of Africa and Sahel related to those in North Africa, who spoke languages belonging to the Afroasiatic family; Negroes in most of the rest of the subcontinent (hence, the toponym Black Africa for Africa south of the Sahara), who spoke languages belonging to the Niger-Congo and Nilo-Saharan families; and Khoisan in Southern Africa, who spoke languages belonging to the Khoisan family. Climate zones and ecoregions Sub-Saharan Africa has a wide variety of climate zones or biomes. South Africa and the Democratic Republic of the Congo in particular are considered megadiverse countries. It has a dry winter season and a wet summer season. The Sahel extends across all of Africa at a latitude of about 10° to 15° N. Countries that include parts of the Sahara Desert proper in their northern territories and parts of the Sahel in their southern region include Mauritania, Mali, Niger, Chad and Sudan. The Sahel has a hot semi-arid climate. South of the Sahel, a belt of savanna (the West and East Sudanian savannas) stretch from the Atlantic Ocean to the Ethiopian Highlands. The more humid Guinean and Northern Congolian forest–savanna mosaic lie between the savannas and the equatorial forests. The Horn of Africa includes hot desert climate along the coast but a hot semi-arid climate can be found much more in the interior, contrasting with savanna and moist broadleaf forests in the Ethiopian Highlands. Tropical Africa encompasses tropical rainforest stretching along the southern coast of West Africa and across most of Central Africa (the Congo) west of the African Great Lakes. In East Africa, woodlands, savannas, and grasslands are found in the equatorial zone,