Angiosperm wood with insect tunneling
Blue Forest area, Wyoming, U.S.A.

Here is fossil evidence of insect tunneling within an unidentified wood found in what were originally freshwater deposits. Judging from the variable size of the burrows, two species of insect were present. The banding in the smaller tunneling was produced as a grub packed the debris that it chewed away as it burrowed through the wood. The speckled material is sediment that entered the burrows after the wood was buried and subsequently silicified.
Copyright © 2000 Giraud Foster & Norman Barker