What are Some Burrowing Animals?
Many burrowing animals have existed, including numerous mammals, insects, amphibians, reptiles (including small dinosaurs), crustaceans, worms, and even a few fish and birds. The start of the modern era of life, the Phanerozoic, is defined by the appearance of complex burrows in the fossil record 542 million years ago. These burrowing animals broke up the previously hard-packed and anoxic ocean floor, allowing much greater biological diversity as well as interspecies competition. Burrowing is thought to have evolved as a defense against predation. Many ecological arms races between predators and prey can be characterized as burrowing animals versus predators trying to get animals out of their burrows.
