https://www.cnet.com/news/scientists-discover-cthulhu-sea-cucumber-that-terrorised-oceans-430-million-years-ago/

Researchers ground the fossil, layer by layer, to create a 3D reconstruction of Sollasina cthulhu (the tube feet are shown in different colors).

The team at Oxford recreated the 3D by grinding away thin layers of the fossil, taking individual photographs at each stage to create a "virtual fossil."