Johnston briefly mentioned the teeth of a "thecodont saurian" he named Astrodon in a paper on the teeth of Hadrosaurus, but provided no description. He sectioned one tooth for viewing under a microscope, and the name Astrodon alludes to the rather starburst-like "multitude of minute tubuli radiating from the narrow elliptical section of the pulp cavity" as later described and illustrated by Leidy. The external form of the teeth was spoon-shaped, typical of brachiosaurids. Treated by some researchers as a valid senior synonym of Pleurocoelus.