The indefatigable Pete Grube has identified this plant correctly. It is Arabis lyrata, the Lyre-leaved Rock Cress, or whatever they call it now. Winter leaves are often thicker and with lobes more blunt. When it flowers on the foredunes in early spring, the basal leaves wither away very early, and often are not visible at all. Photographed in the high dunes of the Indiana Dunes State Park on a warm November 6, 2011. Good call Pete!
It's enjoyable to find something green and growing in November when most plants are going dormant. This is one of my favorite plants - I like the display of radial symmetry (though imperfect) and the fact that the upper layers of leaves are positioned so as not to block sunlight from the lower. Even more remarkably, the lobes on the upper leaves tend to be directly above the sinuses (empty spaces between lobes ) below!