Fins

Credit: Daisy Chung; Source: John A. Long, and “Elpistostege and the origin of the vertebrate hand,” by Richard Cloutier et al., in Nature Vol. 579, March 18, 2020

How a 380-Million Year-Old Fish Gave Us Fingers

A remarkable fossil reveals.
How Fins Evolved

The new study by paleontologists from the University of Chicago, published this week in the Proceedings of the National Academy of Sciences, uses CT scanning to examine the shape and structure of fin rays while still encased in surrounding rock. The imaging tools allowed the researchers to construct digital 3D models of the entire fin of the fishapod Tiktaalik roseae and its relatives in the fossil record for the first time. They could then use these models to infer how the fins worked and changed as they evolved into limbs.