A weird combination of Deinotherium and Platybelodon- Elephantiformes without ivories
In the main Proboscidean taxon of Elephantiformes, a huge pair of developed top incisors (ivories) has become a distinctive feature of this taxon. The structure is usually made as a tool for individual foraging and a weapon for males to compete for mating. The Proboscidean taxon without ivories usually and only exists in the primitive taxon that were differentiated before Oligocene, for instance, Deinotherium merely developed a pair of hooked lower incisors and its top incisors were totally missed. In the early revolving period of Elephantiformes, a group termed as Amebelodontidae appeared, whose lower jaw and lower incisor are elongated and widened specially to form a shovel-shaped structure. The researchers were always interested in the weird evolution direction. Many hypotheses and studies have been made about the functional and morphologic significances of shovel-shaped lower jaws in Amebelodontidae.