'Cthulhu' fossil suggests monstrous sea cucumber precursor

A newly discovered fossil has given insights into a monstrous relative of the sea cucumber.

University of Oxford researchers created a computer-generated reconstruction of the 430 million year-old, 3cm-wide fossil recovered from Herefordshire, named Sollasina cthulhu.

The fossil is named for its resemblance of fictional monsters in HP Lovecraft’s fictional Cthulhu universe, owing to its multiple tube-like tentacles.

Lead author of the study Dr Imran Rahman said: “Sollasina belongs to an extinct group called the ophiocistiods, and this new material provides the first information on the group’s internal structures.”

Analysis was carried out to determine whether Sollasina was more closely related to sea cucumbers or sea urchins. Researchers identified an internal ring, interpreted as part of a water vascular system of canals used for feeding and movement, similar to the modern sea cucumbers. This characteristic was previously unknown in fossil echinozoans.

Co-author Dr Jeffrey Thompson said: “To our surprise, the results suggest it was an ancient sea cucumber. This helps us understand the changes that occurred during the early evolution of the group, which ultimately gave rise to the slug-like forms we see today."

Sollasina belongs to the extinct group of ophiocistioids, dating from the Palacozoic and early Mesozoic era.

To reconstruct the fossil digitally, researchers ground the fossil away layer by layer, taking photographs taken at each stage. The fossil slices and the 3D reconstruction are now being housed at Oxford University Museum of Natural History.

The team is comprised researchers from University of Southern California, Yale University, University of Leicester and Imperial College London. Their findings have been published in Proceedings of the Royal Society B.