Baynunah Geological Formation Fossil Sites in Abu Dhabi Six to eight million years ago in western Abu Dhabi, a complex of wide rivers supported animals such as elephants, hippopotamuses, giraffes, monkeys, carnivores, ostriches and crocodiles

Research over the years has revealed that in the ancient past, the landscape and ecology of the Al Dhafra region of western Abu Dhabi was quite different to what is found today. Although there is evidence that arid conditions existed then as now, creatures there were sustained by a large river system flowing through the area. The river and semi-arid climate supported grass, shrubs and trees, including palm and acacia trees. The animals living in this environment resembled those known from Africa during the same period, but there were also similarities with Asian and European species of that time. The fossils of these animals have been found in the Baynunah Geological Formation, which is comprised of river sediment such as sand, gravel and clay. Fossils can be found today at a series of hills along the coastline of the Al Dhafra region as well as into the desert interior.

Prehistoric animals
Animal fossils found in the rock include a type of hippopotamus that was smaller and more primitive than the living hippopotamus of Africa. The elephant fossils showed this animal had four tusks instead of the two found on elephants today. Several species of giraffes and six species of antelopes were found, suggesting a lightly wooded environment, not the desert environment of today. Three varieties of ancient turtle were found at the site, including a very large, land-based, plant-eating turtle that resembles giant turtles living today. At least three kinds of fish lived in the river, providing food for crocodiles and land-based scavengers. The Baynunah Formation fossils most closely resemble animals from this period that are found across North Africa, East Africa, Pakistan and even China. Meanwhile, these Baynunah animals show less resemblance to European fossil animals. This suggests that during Baynunah times, animals could migrate freely in an east-west direction, but that north-south movement may have been restricted by barriers presented by ancient deserts, mountains or river systems.

The river
The river had numerous channels – probably no more than three metres deep – but the entire braided river network was hundreds of metres across at its widest point. The river flowed year-round, as shown from the presence of large freshwater turtles and crocodiles, including the gharial, a fish-eating crocodile with a long, thin snout. At the same time, the presence of catfish suggests that the flow was sluggish or intermittent in some of the river channels. There also were occasional periods when the river moved much faster, perhaps during monsoon rains. At that time, the sea level was substantially lower than today, and the marine coastline was about 300 kilometres to the east of its present location.