The fossil whorls were a mystery. In 1899, geologist Alexander Karpinsky described an odd spiral of teeth, the first known fossil of its kind, uncovered from the ancient rocks of Krasnoufimsk, Russia.
A study in the Journal of Morphology shows how the bizarre prehistoric ratfish called a Helicoprion ate with its unique set of choppers. A Helicoprion was a prehistoric ratfish that featured perhaps ...