For your readers -
A yardang is a rock ridge feature caused by wind and water erosion. The word itself is of Turkish origin, meaning ‘steep bank’. Some are found in dried-up riverbeds. Yardangs may also be found in deserts and may form very unusual shapes and some resemble various objects or even people.
Yardangs are elongate features typically three or more times longer than they are wide, and when viewed from above, resemble the hull of a boat. Facing the wind is a steep, blunt face that gradually gets lower and narrower toward the lee end1. They come in a large range of sizes, and are divided into three different categories: mega-yardangs, meso-yardangs, and micro-yardangs. Mega-yardangs can be several kilometers long and hundreds of meters high, meso-yardangs are generally a few meters high and 10 to 15 meters long, and micro-yardangs are only a few centimeters high.
They have pills that can turn a micro to a meso.