What is "sinomammut"

Sinomammut (meaning "Chinese Mastodon") is a proboscidean found in the Miocene of China. It was known from a single, fragmentary, mandible found in the 1990s. However, most of the specimen has been lost, leaving only the right ramus and an in-situ photograph of the mandible. The mandible was originally thought a gompothere closely related to Sinomastodon, but an analysis revealed it to actually be a mammutid that was a sister group to the well-known Mastodon. It can be distinguished from the mastodon by its lack of lower tusks.