The mystery of the Tully monster continues to puzzle scientists. While two separate groups have claimed to have answered the question of the strange sea creature last year -- saying the "monster" is actually a fish called the lamprey -- a new report published in Palaeontology disputed these findings, saying evidence proves otherwise.
Led by Lauren Sallan of the University of Pennsylvania, a new team of paleobiologists is now disputing earlier claims about the mysterious Tully monster. The team is saying that the declared classification don't fit the facts about the creature because of its extreme weirdness.
"It has these eyes that are on stalks and it has this pincer at the end of a long proboscis and there's even disagreement about which way is up. But the last thing that the Tully monster could be is a fish," Sallan explained in an official release from Penn News.
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First discovered in the 1950s, the Tully monster or Tullimonstrum gregarium was initially classified as a worm. Sallan said there is an ongoing argument whether to define the organism as a mollusc or an arthropod.
Last year, two different groups released reports that the animal can be classified as a vertebrate. However, the new study revealed that neither groups were able to definitively classify the Tully monster as such.
Co-author Sam Giles, who is a junior research fellow at the University of Oxford, stressed the importance of exploring all areas of evidence including anatomical, preservational and comparative.
"Applying that standard to the Tully monster argues strongly against a vertebrate identity," he added.
The first group pointed to internal structures found in fossil samples, while the second explained that complex tissue structures in the eyes make it more likely that the Tully monster was a vertebrate.
The Palaeontology study dismissed both findings, saying that there weren't much internal structure preserved to prove the vertebrate argument.
The possession of complex eyes does not necessarily mean the animal is a vertebrate as other non-vertebrate species are known to have complex eyes as well. Furthermore, the team's examinations showed that the Tully monster was more likely to have the much simpler cup eyes.