A creature with more than a passing resemblance to HP Lovecraft’s terrifying Cthulhu once actually existed, palaeontologists have revealed – although at just three centimetres wide, it was hardly a danger to shipping or buildings.
Not, of course, that there were any human-made structures around when Sollasina cthulhu prowled across the ocean floor some 430 million years ago.
The creature, a very distant ancestor of sea cucumbers and sea slugs, is revealed in a paper published in the journal Proceedings of the Royal Society B.
It was found in fossilised form in the UK county of Hereford. A team of researchers led by Imran Rahman from the University of Oxford then spent months painstakingly grinding it away, taking photographs at every stage, resulting in an accurate 3D computer reconstruction.
The creature boasted a couple of dozen tubular tentacles, which it used, Rahman and colleagues suggest, to both move around the seafloor and suck up prey.
The careful slicing of the actual fossil in order to create a virtual model may seem problematic, but doing so revealed internal structures that would have remained invisible if the original artefact was left intact.
In particular, the researchers report, the imaging showed up an internal ring – thought to be evidence of a water-filled vascular system, similar to those found in its present-day descendants.
“Sollasina belongs to an extinct group called the ophiocistioids, and this new material provides the first information on the group’s internal structures,” says Rahman.
Co-author Jeffrey Thompson adds that their findings offer new insight into the evolution of a large and widespread group of animals.
“We carried out a number of analyses to work out whether Sollasina was more closely related to sea cucumbers or sea urchins,” he says.
“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.”