Scientists Reconstruct 430 Million-Year-Old Tentacled 'Cthulhu' Fossil, Reveals Monstrous Relative of Modern Sea Cucumbers

Scientists have found and reconstructed a 430-million-year-old fossil that gave some fascinating insights into the evolution of sea cucumbers. This extraordinary find, from Herefordshire in the U.K., and named Sollasina cthulhu, has turned out to be an odd creature with several tentacle-like appendages that would make it look pretty fearsome to its small marine neighbors, stated the University of Oxford.

"Sollasina belongs to an extinct group called the ophiocistioids, and this new material provides the first information on the group's internal structures," said Dr. Imran Rahman, Deputy Head of Research at Oxford University Museum of Natural History. Though only three centimeters wide, the creature had 45 tentacle-like tube feet that it used for locomotion and hunting, making it a formidable predator on the ancient seafloor.

The research into the fossil used a particularly innovative approach, where the researchers ground away the specimen layer by layer, photographing each stage to create hundreds of slice images. "We carried out a number of analyses to work out whether Sollasina was more closely related to sea cucumbers or sea urchins," notes Dr. Jeffrey Thompson from the University of Southern California. And surprisingly, the results pointed to 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," Thompson further stated, according to Everything Dinosaur.

Its name is drawn from the Cthulhu created by H.P. Lovecraft because of the monster-like appearance of this creature, as per the University of Oxford. It was here that an international research team, including scientists from the Oxford University Museum of Natural History, the University of Southern California, Yale University, the University of Leicester, and Imperial College London, made the connection, looking at some of the more unusual features exhibited by the fossil. The biggest breakthroughs of the study were made using the advanced 3D reconstruction technique, unveiling internal structures not previously known. They found in it an internal ring, which they interpreted as part of the water vascular system—a very complicated network of fluid-filled canals for feeding and movement among modern sea cucumbers and their relatives.

The famous Herefordshire fossil site in England has preserved not only the hard but also the soft tissues of ancient organisms, some of which come out very useful in piecing together the story of early marine life. This exceptionally well-preserved quality at this locale was because of fine-grained volcanic ash that had settled on these sea floors during the Silurian period.

According to Yale paleontologist Derek Briggs, "our analysis strongly suggests that ophiocistioids diverged from the line leading to modern sea cucumbers," which shows just how gradual the modification of the sea cucumber skeleton was in the assembly of its body plan, stated YaleNews. Such an evolutionary insight helps bridge the gap between ancient and modern sea cucumbers, showing how over millions of years these creatures transformed into the species we know today.