Now, scientists have cracked the code on how these elusive Arctic whales grow such an impressive and unique tool.

An international team of researchers, including scientists from Denmark's Aarhus University, have uncovered that these straight, spiraled tusks – which can grow to more than two meters (6.6 ft) over the whale's 80-plus years – are no fluke. There's a complex mix of physics and minerals involved in their formation.

Recently, we wrote about how, in nature, such features are loaded with an evolutionary cost – usually energy that could be allocated elsewhere. For narwhals, such energy could have otherwise been spent on more efficient fat storage or other metabolic functions to make life easier in their cold, harsh environment.