325,000-year-old elephant tusks found in Nafud Desert

Saudi and foreign archeologists have discovered a 325,000-year-old elephant tusk in the Nafud Desert in the north of the Kingdom, suggesting the Arabian Peninsula was much greener and wetter in the past.
The tusk comes from the now extinct genus known as Palaeoloxodon, the so-called straight-tusked elephants. The two pieces of tusk found during the excavations together measure 2.25 meters in length.
From the size of a carpal bone found 5 meters away, the researchers have made initial estimates that the animal weighed between 6 tons and 7 tons and stood over 3.6 meters at the shoulder.
A modern African elephant weighs between 3 tons and 6 tons with males averaging around 3.3 meters at the shoulder.
A joint research team led by archaeologists from Oxford University and the Saudi Commission for Tourism and Antiquities (SCTA) made the startling discovery in an embedded lake.
The findings were revealed at the three-day Green Arabia conference 2014, which concluded Friday. It was organized by Oxford University in collaboration with the SCTA at St John's College.
Mike Petraglia, from the school of archaeology at Oxford University, led the team. He said the sand layer was dated to around 325,000 years ago, which suggests that the elephant remains found are about that age.
Petraglia said the elephant tusk was a significant paleontological find and shows that the Arabian desert was quite green.
"Although the sand dunes in the Nafud Desert carry on for miles in the present day, around 325,000 years ago it seems the landscape would have been very different," he said.
"The discovery of the elephant tusk is significant in demonstrating just how much the climate could have changed in the Arabian desert. Elephants would need huge quantities of roots, grasses, fruit and bark to survive and they would have consumed plenty of water too," he said in his research note.
Prince Sultan bin Salman, the SCTA president, delivered a keynote address highlighting the nature of the Arabian Peninsula environment in the past.
He said the SCTA's five-year cooperation with Oxford on the "Green Arabia Project" would end in 2017.
As a starting point, the research team had analyzed satellite imagery, which revealed a network of ancient rivers and lake beds in the Arabian Peninsula.
Using this photographic evidence, they selected sites near ancient water sources for their excavations because these were places where animals and early humans would have gathered.
The research team also discovered other animal remains in the same sand layer, including a big cat, thought to be a now-extinct jaguar and the remains of a member of the horse family, as well as an oryx, an antelope species native to the Arabian Peninsula.