These are not cracks. They do not go through to the inside. During forming the clay was folded over itself rather than compressed against the mold.
Laminations in pugged the pugged clay body matrix or in a formed piece can cause separations during drying and firing or produce a fired matrix prone to cracking and failure under stress.
Jiggering is a process of forming pottery that employs a spinning plaster mold and a tapered template to press soft clay or porcelain against it.