Ammonites – extinct marine molluscs – flourished in Earth’s oceans until they were wiped out by an asteroid, along with three-quarters of species at the time, around 65 million years ago.
You may be familiar with the ammonite’s snail-like fossilised shell, but as curator of the American Museum of Natural History Neil Landman explains in the video below, there were at least 30 different ammonite shapes – from the paper-clip-like hamiticones to the twisty-turny nipponites and everything in between.