Bos primigenius (the aurochs) was the ancestor of domestic cattle. They were a type of large wild cattle which inhabited Europe, Asia and North Africa, but are now extinct. Aurochs bulls are believed to have reached a height of 1.8 metres at the withers, and the cows to have been about 1.5 metres, displaying considerable sexual dimorphism. These animals used to live in the London area during the Pleistocene.
NHMUK PV OR 50086 corresponds to one of the most complete skulls of this species from Britain. It was found with other mammals such as beaver, brown bear, lion, straight tusked elephant, steppe mammoth, horse, red deer, narrow-nosed rhinoceros in the Uphall Brickfield at Ilford in Essex in 1864. These fossils represent the later stages of a major temperate episode dating to around 200,000 to 170,000 years ago. The aurochs specimen is on a long term loan to the Museum of London since 2003 and is now available as surface scans for download.