Crenulation

Imagine you are playing with a sheet of paper and a pair of scissors. You cut five or six V shapes at the bottom of the paper. These V shapes are like the teeth of a comb. Now take one of the V shapes and fold it over the edge of the paper. This is called crenulation!

In nature, mountains and hills can have a similar shape. They have bumps (like the Vs you cut in the paper) called peaks and ridges, and these can be eroded by wind and water. Over time, this can make the peaks and ridges look like a comb with teeth. This is called crenulation too!

The term "crenulation" can also refer to the shape of certain sea creatures. Think of a starfish. The arms that stick out from the center are often shaped like a V, just like the teeth on the paper. This is another example of crenulation.

So, whether it's a paper, a mountain, or a sea creature, if it has V-shaped teeth or bumps that look like a comb, it's crenulated!