I have had these and others in my collection for about 27 years, most of them have been wrapped up or still are wrapped up since I collected them with my son. I always classified them as Ripple Marks, but wonder if they are, we collected them a little to the West of Sundance, Wyoming in exposure that is supposed to be from the Upper Jurassic / Morrison Formation.
What is your opinion??
Top of Plate
Bottom of Plate