Ripples are commonly called ripple marks, but not by geologists. Ripples are a telling sign of the ancient environment that formed the rocks in which they appear. For instance, the ripples in this Paleozoic limestone from upstate New York are high relative to their wavelength, the distance between wave crests. That marks them as aqueous ripples—they formed in water, not wind. And these ripples are symmetrical, not leaning to one direction. That marks them as oscillation or wave ripples, as opposed to current ripples.
It was a flat and shallow seabed of nearly pure limy mud where these linear ripples formed, in the outer surf zone where the waves move steadily back and forth overhead. Places like it today are found in the Bahamas. Ripples are one of the most commonly preserved sedimentary structures, because it takes only a small storm or other event to cover and preserve them.