X-ray vision brings new life to a fossil flattened by time

The Muen plateau, on the island of Edgeoya, where the Oda fossil was found. — @2023 The New York Times Company

WHILE exploring an Arctic mountaintop in 2008, paleontologists unearthed a small skeleton that resembled a coiled sea serpent imprinted into a slab of 240 million-year-old rock. The remarkably complete skeleton, nicknamed Oda, was deposited in the collection of the University of Oslo’s Natural History Museum.

It was clear that Oda was an ichthyosaur, but no one could say if it was a known species of the marine reptiles, which were like a mashup of a crocodile and a dolphin. While most of its skeleton remained, eons under a muddy seafloor had squeezed Oda into a two-dimensional jumble of bones.