Liu and his colleagues weighed in on the debate by analyzing the ratio of oxygen-16 and oxygen-18 isotopes preserved in the teeth of Moeritherium fossils.
The main clue was that the variation in oxygen isotope ratios among Moeritherium samples was extremely low.
Creatures in the proboscidean genus Moeritherium have been known for more than a century, but scientists have never agreed about how the animals lived, says Alexander G.S.C.
Other creatures featured in this show include Andrewsarchus, a one-ton, wolf-like mammal with a devastating 3ft-long jaw; herds of Bronththere, big herbivores that spread across the northern hemisphere; and Moeritherium
, an early type of elephant that looks more like a large aquatic pig, living in the mangrove swamps.
did not resemble its later cousins--it was somewhat larger than a modern-day tapir, but with short legs, a relatively long body, and a short tail.