This is a 3D reconstruction of Sollasina cthulhu. Tube feet are shown in different colors.  Credit: Imran Rahman, Oxford University Museum of Natural History

ScienceDaily has a story about an ancestor of modern sea cucumbers.  The animal, called Sollasine cthulhu, lived 430 million years ago during the Silurian Period in what is now Herefordshire in the UK.  It resembles one of the monsters from the fictional universe created by author H.P. Lovecraft.  The description is in a paper, by UK and USA paleontologists, which appeared in the journal Proceedings of the Royal Society B.

Although the fossil is just 3 cm wide, its many long tentacles would have made it appear quite monstrous to other small sea creatures alive at the time. It is thought that these tentacles, or ‘tube feet’, were used to capture food and crawl over the seafloor.

Like other fossils from Herefordshire, Sollasina cthulhu was studied using a method that involved grinding it away, layer-by-layer, with a photograph taken at each stage. This produced hundreds of slice images, which were digitally reconstructed as a ‘virtual fossil’.

This 3D reconstruction allowed palaeontologists to visualise an internal ring, which they interpreted as part of the water vascular system — the system of fluid-filled canals used for feeding and movement in living sea cucumbers and their relatives.