As if out of a sci-fi thriller, a sea creature with tentacles protruding from its mouth has been discovered; well, its fossil has. The previously unknown "sea monster," which scientists dubbed Daihua sanqiong, lived an amazing 518 million years ago in what is now China. And the extinct animal shares a number of anatomical characteristics with the modern comb jelly, a little sea creature that uses so-called comb rows full of loads of hair-like cilia to swim through the oceans. The discovery suggests that this newfound species may be the comb jelly's distant relative, said study lead researcher Jakob Vinther, a paleobiologist at Bristol University in the United Kingdom.

"With fossils, we have been able to find out what the bizarre comb jellies originated from," Vinther said in a statement, "Even though we now can show they came from a very sensible place; it doesn't make them any less weird."

This finding, however, has sparked a debate. "While the discovery of D. sanqiong is impressive, it's hard to say whether this ancient creature is part of the lineage that produced comb jellies," said Casey Dunn, a professor of ecology and evolutionary biology at Yale University, who was not involved with the study. "I am highly skeptical of the conclusions they draw," Dunn added.

Moreover, the D. sanqiong fossil bears an intriguing resemblance to other known ancient animals, including Xianguangia, another ancient creature with 18 tentacles, and the tulip-like sea creatures Dinomischus and Siphusauctum.

"To make a long story short, we were able to reconstruct the whole lineage of comb jellies," by doing anatomical comparisons, Vinther said. "This is a big deal, because some scientists argue that these swimming carnivores were among the first animals to evolve on Earth, based on family trees analyses and genetic modeling of modern comb jellies. But now, this international team has possibly shown that comb jellies have a long lineage that precedes them," says Vinther.

This newly described lineage suggests that some of the ancestors of comb jellies had skeletons and that their ancient tentacles evolved into the combs with the densely packed cilia seen on comb jellies today. Either way, this new discovery and recent similar discoveries, seem to shake up what experts had previously considered and gives a look into just how much we have yet to learn about our ancient world.