Isolation is essential to evolution. Whether they’re reproductive, behavioral, or geographic, barriers are what create opportunities for species to split off into something new. And given the odd array of mammals that evolved in South America during the time of the continent’s time as an island between the end of the Cretaceous and its connection with Panama around 13 million years ago, it’s easy to comprehend why 20th century paleontologist George Gaylord Simpson deemed the landmass a case of “splendid isolation.” Among the wondrous spinoffs to come out of this time were the astrapotheres.

There isn’t a common term for what an astrapothere is. Some of them looked sort of like hippo elephants – bulky herbivores with elongated tusks