The Devil’s Corkscrew Mystery

The mysterious origin of Nebraska’s ‘Devils Corkscrews’ 

Devil's Corkscrew is the nickname for a type of fossil burrow found in the badlands of Nebraska. In the 1800s, geologists in Nebraska discovered strange spiral-shaped fossils. They were so different from anything else that had been found before that they were given the name "Devil's Corkscrews." For many years, scientists were baffled by the origin of these fossils. Some thought they were the remains of giant freshwater sponges, while others believed they were the work of ancient beavers.

It wasn't until the 1970s that the mystery of the Devil's Corkscrews was finally solved. Scientists discovered that they were actually the burrows of a now-extinct beaver called Palaeocastor. Palaeocastor was a much larger beaver than the beavers we know today, and it had a unique way of building its burrows. Instead of digging straight down, Palaeocastor would dig a spiral-shaped burrow that led to a chamber at the bottom. This chamber was used for sleeping and raising young.

Daemonelix burrows in the Miocene of Nebraska, USA. (original vintage photo owned by the University of Nebraska.) Photos: James St. John

Palaeocastor was a small beaver that lived in North America during the Miocene epoch, about 20 million years ago. It was about the size of a modern muskrat and had a long, slender snout and large incisor teeth. Palaeocastor burrows were likely used for shelter and for storing food.

Some members of this genus made corkscrew-shaped burrows and tunnels. Like many early castorids, Palaeocastor was predominantly a burrowing animal instead of an aquatic animal. Fossil evidence suggests they may have lived in family groups like modern beavers.

The discovery of Palaeocastor sprang from the discovery of devil's corkscrews in the plains of Sioux County, Nebraska, as a tree-sized, screw-like underground formation. Its basic form is an elongated spiral of hardened earth material that inserts into the soil as deep as 3 metres (9.8 ft). These puzzling structures first came to notice through Dr. E. H. Barbour of the University of Nebraska around Harrison, Nebraska, in 1891 and 1892.

Facts about Devil's Corkscrew:

• The burrows are typically found in soft, sandy soil.
• They are often found in groups, suggesting that Palaeocastor lived in colonies.
• The burrows can be up to seven feet long and three feet wide.
• The spiral shape of the burrows is thought to help to ventilate the burrow and keep it cool.
• The Devil's Corkscrew burrows are a popular tourist attraction in the badlands of Nebraska and Wyoming.

Daemonelix, fossil rodent burrow created by Palaeocastor, Sioux County, Nebraska, USA, Early Miocene Right photo: From the National Museum of Natural History, By: FunkMonk Left photo: Exhibit in the Royal Ontario Museum, Toronto, Ontario, Canada., By: Daderot

The Devil's Corkscrew is a fascinating example of trace fossil, which is a fossil that preserves the evidence of an animal's activity rather than the animal itself. Trace fossils can provide valuable information about the behavior and ecology of extinct animals.

In addition to the Devil's Corkscrews, there are many other types of trace fossils. Some of the most common types include footprints, coprolites (fossilized feces), and burrows. Trace fossils can provide us with a wealth of information about ancient animals, and they are an important part of the fossil record.