Tonganoxichnus Fossil
Kansas Geological Survey (University of Kansas)
www.kgs.ku.edu/kgs.html
Research Gate
https://www.researchgate.net/figure/Minor-morphological-variation-in-Tonganoxichnus-robledoensis-A-Complete-trace-with-i_fig5_230034003
Tonganoxichnus Fossil
Introduction to Paleobiology and the Fossil Record
www.blackwellpublishing.com/paleobiology