アメリカ自然史博物館さんのインスタグラム写真 - (アメリカ自然史博物館Instagram)「Happy Fossil Friday! This boomerang-headed critter is Diplocaulus magnicornis. It lived some 275 million years ago during the Early Permian in what is now Baylor County, Texas. Like other nectrideans (an extinct order of tetrapods), this species had two projections at the back of its skull, creating its signature boomerang shape. Scientists aren’t sure what its exact function was, but it was presumably related to the way the animal swam. Diplocaulus probably lived in ponds and streams. Photo: M. Pelczar / © AMNH #paleontology #fossils #history #didyouknow #amazinganimals #nature #paleoart」9月15日 22時46分