This is a detail of the fossil Anisopus deweyanus also shown on this site.
Named in honor of Edward Hitchcock's good friend, Rev. Professor Chester Dewey, this was the first type of track Hitchcock recognized as belonging to a four-footed (quadrupedal) animal. He reported them as bird tracks in 1840, but by 1842, had changed his mind. By 1858, he had described 54 track species as belonging to quadrupeds.