By most standards, the platybelodon was an odd looking animal—while resembling modern elephants, it also had a protruding lower jaw with horizontal teeth that Sanders believes were used in a scythe-like manner to mow down grass for consumption. Platybelodon fossils were first discovered and described back in the early 1920’s. Since that time, many more fossils (particularly in China) have been found helping to give researchers a better picture of what the animal actually looked like. It’s now pretty clear that they lived approximately 8 to 20 million years ago in Africa, Asia and even made their way to North America. But because their upper mouth region, snout or trunk, was made of softer material that didn’t fossilize very well, researchers have not been able to see what the upper part of the mouth or trunk actually looked like. For that reason, they have had to put forth theories to explain why an animal would grow a lower jaw the way it did and how an upper mouth or trunk might make best use of what it had—otherwise, neither would have evolved the way it did.
Read more at: Phys.org