Chinese scientists reveal evolution of feeding organs in early elephantiforms

BEIJING, Dec. 1 (Xinhua) -- Chinese scientists have recently revealed the unique evolution process of feeding organs in early elephantiforms through research on mandibles and trunks, according to the Science and Technology Daily on Friday.

Early in the Middle Miocene Epoch about 15 million years ago, the Platybelodon, a genus with shovel-like mandibles in early elephantiforms, had developed a feeding pattern of rolling plants with their trunks and cutting plants with their mandibles, which is the earliest evidence that elephant trunks had the curling function.

Scientists from the Institute of Vertebrate Paleontology and Paleoanthropology under the Chinese Academy of Sciences reconstructed the feeding behavior of major groups of longirostrine elephantiforms through comparative functional and eco-morphological investigations, as well as feeding preference analysis.

They discovered that early elephantiforms with various mandibular shapes had different ecological adaptability. As the environment gradually became dry and cold, Platybelodon feeding on herbs adapted to the relatively open regions, which led to the development of the trunk-grabbing function and flexibility, according to Wang Shiqi, researcher from the institute.

Wang further explained that the adaptation of feeding behavior in the open environment was the catalyst for the evolution of elephant trunk-grasping function. Elephants rely solely on their trunks for feeding in the open region, eventually resulting in the regression of the previous feeding organs -- mandible and lower incisors.

The study was published in the journal eLife.