Burrow fossils are the remains of holes or tunnels excavated into the ground or seafloor by animals to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion preserved in the rock record. Because burrow fossils represent the preserved byproducts of behavior rather than physical remains, they are considered a kind of trace fossil.
Fish burrows
Fossil Lungfish burrows are preserved in the Rocky Point Member of the Chinle Formation in Canyonlands National Park.
References
Burrow fossil Wikipedia(Text) CC BY-SA