Claw Impressions in the Walls of Modern Mole (Scalopus aquaticus) Tunnels as a Means to Identify Fossil Burrows and Interpret Digging Movements

Casts of the foraging tunnels of eastern American moles ( Scalopus aquaticus ) show impressions from the moles' mani along the lateral walls. The number of discernable impressions ranges from one to five, each showing two or three long, flat, blunt-ended claws. The size and shape of the impressions matches the claws on the paddle-like manus of S. aquaticus . The impressions are spaced at regular intervals of about two cm, and probably represent points at which the mole pushed off from the tunnel wall with alternating laterad digging strokes. Tunnel width generally exceeds height by about 15%, reflecting the laterally compressed body of the mole. These tunnel casts help show that clear, recognizable traces can be preserved in loose, humic soils, and demonstrate the type of traces left by a “lateral-thrust” digger with fully sprawled stance, such as S. aquaticus . Identification of traces on the tunnels of living moles may be applied to the fossil record, in which fossilized burrows with similar marks could be attributed to extinct burrowing moles or mole-like locomotion.

Keywords:

• Scalopus aquaticus
• mole
• ichnology
• burrows
• digging

ACKNOWLEDGEMENTS

I thank L. Martin of the University of Kansas Division of Vertebrate Paleontology for his advice on this project and insights on rodent and other fossil burrows. J. Chorn and J. Kozisek of the Division of Vertebrate Paleontology assisted with photography and tunnel casting. Additional thanks to D. Miao, A. J. Martin, and J. F. Genise for their constructive critical reviews of the manuscript.