"We have two specimens of this species in the Cabinet, which I have tried in vain to refer to any others described in this Report. They are not as good as I could wish; they they show the general characters of the tracks and the mode of progression. I find the smallest track behind the other, and hence have spoken of it as made by the hind foot; which is contrary to the general analogy of these footmarks, and yet by no means without precedent both among living and fossil species. The unusual width of the body has led me to refer this species to Chelonians [turtles]; and yet the length of the step is great for such animals. But the legs were long if it were a chelonian, since there is no evidence that either tail or carapace dragged upon the ground."
From Edward Hitchcock, Ichnology of New England
Scale: The actual specimen is six inches wide.