Malea Ringens aka Grinning Tun Sea Snail Shell

Malea ringens is a large sea snail that grows up to 270mm. The common name is Grinning Tun. This example is 125mm which is 4 1/4" long and is a medium sized example. Well that is all there is to say about this.
But what is notable about this shell is that it is made up of smooth ridges or whorls. They start from a single point at the rear of the shell and radiate from there.
Many more shells and dinosaurs left to go.