It took a long time for palaeontologists to recognize even the most spectacular burrows. The history of a controversy around the most famous of these will serve as an example (Schultz 1942, Martin and Bennett 1977).
In 1893, Erwin Barbour described a new fossil from the Tertiary of Nebraska. He called it the devil's corkscrew, and gave it the Latin name Daimonelix. At this time, it was still debated in what environment the continental Tertiary sediments were deposited. Barbour thought that Daimonelix was preserved in lake sediment, and, accordingly, he interpreted it as a sponge, even after a skeleton of a rodent had been found inside the fossil.
At the same time, two palaeontologists independently suggested that the fossil was the cast of a burrow. It took half a century for this view to become accepted.
When Barbour examined the fossil under the microscope, he found plant tissue. It was then suggested that the fossil is of a liana. Some believed devil's corkscrews to be concretions, and so altogether inorganic in origin.
Only in 1942, Schultz brought together the evidence that devil's corkscrews were indeed burrow casts. The plant tissue that had been the basis of the plant hypothesis was shown to have come from roots that grew into the burrow. The surface of burrow casts contained marks left by claws of the animal.
|History
Identifying the animal
