Burrow fossil

Burrow fossils are the remains of burrows - 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. One common kind of burrow fossil is known as Skolithos, and the similar Trypanites, Ophiomorpha and Diplocraterion.

Fish burrows
Fossil Lungfish burrows are preserved in the Rocky Point Member of the Chinle Formation in Canyonlands National Park.

Invertebrate burrows
Examples are Treptichnus pedum and Arenicolites franconicus.