Originally Posted by jtgotsjets

It should be noted that what makes a cottered crank "cottered" are those two little bolts you see sticking out of the crank arm near the center.
I mention it because there are a lot of older bikes with cotterless cranks that look more like the picture of cottered cranks. The telltale sign is that the two bolts will be missing.
The one piece crank is pretty obvious.