Not sure how I came by it, but I call them "pack saddle" stars when I teach beginners ("wrist-lock", no). "Raise your right hand, put it in the center and now lay it on the wrist of the person in front of you, like a pack saddle on a horse, to make a star. Notice you don't need to clamp on or even really use your thumb at all." And yes, very much the default star form from my experience.