Black wildebeest
Features necessary for defending a territory, such as the horns and broad-based skull of the modern black wildebeest, have been found in their fossil ancestors. The earliest known fossil remains are in sedimentary rock in Cornelia in the Orange Free State and date back about 800,000 years. Fossils have also been reported from the Vaal River deposits, though whether or not they are as ancient as those found in Cornelia is unclear. Horns of the black wildebeest have been found in sand dunes near Hermanus in South Africa. This is far beyond the recorded range of the species and it has been suggested that these animals may have migrated to that region from the Karoo.
Black squirrel
Black squirrels can also be found in the United Kingdom, where grey squirrels were first introduced from North America at the end of the 19th century. They are concentrated in Eastern and South Eastern areas of England, but have been witnessed across the country. The origin of the UK's black individuals has been a topic of dispute, with initial research indicating that black-colored individuals are descendants of zoo escapees. Regardless of their origins, the black squirrel population in the UK continues to grow, and around the towns of Letchworth, Stevenage and Hitchin, as well as nearby villages such as Shillington and Meppershall in England, black squirrels are now as abundant as grey individuals. Black squirrels have been present and studied in Cambridgeshire since the 1990s; in the village of Girton three quarters of the squirrel population is black.