the amazing Vanellus chilensis nest

There is an interesting fact about the eggs of the "Vanellus chilensis", its shape.
they do not have the common shape of eggs, they have a sort of "conical" shape with two importante consequences:
First, the conical shape alows better arrangement together;
Second, since the "nest" is, in fact, the bare terrain soil, whitout any constraints to keep then together, the conical shape avoids them to roll far from assumed posicion of the "nest".