Invertebrate tracks from the Coconino Sandstone of Northern Arizona

Variations are noted in the tracks of two invertebrates described by Gilmore from the Coconino sandstone. Comparison with tracks of living arthropods suggests that Paleohelcura almost certainly, and probably Octopodichnus as well, should be referred to scorpionids. Three other forms are tentatively referred to representatives of the Diplopoda, Isopoda and Oligochaeta, and the new genera Diplopodichnus, Isopodichnus and Scolecocoprus are erected to receive them.