Just as precious as the fossils of the constructor found in the burrow are the fossils of the intruders, non-burrowing animals preserved in the infill. They provide evidence of the ecological change that the appearance of burrows in the landscape brings about. The dependency of one animal on another for habitat can be contrasted with dependencies for food. Trophic web is commonly represented as a pyramid, where the top predator ultimately is dependent on all the other organisms in the landscape. In contrast, one burrowing animal creates a new habitat, to which other animals adapt. At least 15 species of vertebrates, and many more invertebrates depend on the gopher burrows, for instance (Voorhies 1975). Some use it for shelter, to others it constitutes their sole habitat.
Fossils of non-digging animals within the burrow may also indicate the mode of filling. For instance, it has been suggested that the bones of a camel found in a fossil beaver burrow (Daimonelix) were washed in during a flood (Martin and Bennett 1975). The strength of the flood can then be roughly estimated. At any rate, it can be confirmed that the burrow was filled by a catastrophic event.
Identifying the animal
|Infill
