Gigantocamelus spatulus. Illustration and photo-reconstruction of the North American gigantic camel Gigantocamelus howling against a backdrop of grazing antelopes. Gigantocamelus was the largest prehistoric ungulate. It lived in the Pliocene through the Pleistocene 4.9 mya - 300,000 years ago. It was 3.7 metres in length and 300 centimetres in height. Its weight was about 1.6-2.4 tonnes. Some believe that it may be a synonym of Titanotylopus.