Scientists can't classify the mysterious monster (4 photos)

The fossil found by scientists of an ancient sea monster, similar at the same time to a cuttlefish, a slug and a giant leech, has been causing consternation among researchers for many years. Science still doesn’t know how to classify the monster, named after its discoverer “Tully’s monster.”







“The Tully Monster,” in honor of the discoverer, scientists named an ancient monster whose fossilized remains still do not know how to classify. The scientific name of the unclassified specimen is Tullimonstrum. It was discovered in 1958 when fossil collector Francis Tully spotted it in the Mazon Creek fossil beds in Illinois. The unusual fossil found by Tully is estimated to be 307 million years old.

The Tully monster most closely resembles a slug-snail. However, where a slug's mouth would be, there is a long, thin appendage with a claw at the end. And this claw is equipped with teeth.

The strange characteristics of the Tully monster make it difficult to classify it as a vertebrate or invertebrate. Recall that a vertebrate is a creature with a backbone. Mammals, fish, birds and reptiles are classified as vertebrates. Invertebrates are creatures without backbones, such as insects, octopuses and crustaceans.





In 2016, a team of scientists examined the fossil and declared that the Tully monster had finally been declassified. The data they obtained indicated that it was a vertebrate animal. After studying the features of the creature's physical form, the researchers stated that the Tully monster had a notochord. The notochord is a flexible rod running the entire length of the body. Although it is not the spinal cord, it is considered the precursor of the spinal cord. Thus, the presence of the notochord suggested to scientists that the Tully monster would most logically be classified as a vertebrate, in the same group as the lampreys.

The study also looked at pigment granules in the creature's eyes, known as melanosomes. After analyzing them, scientists noted that their shape and size were similar to the eyes of other vertebrates, which once again confirmed the right of the Tully monster to belong to this group.



For some time, the 2016 study was considered conclusive for the definitive classification of the Tully monster. However, a new recent study has cast doubt on the 2016 result, bringing the Tully Monster mystery back into scientific discourse. This study also looked at melanosomes. The researchers used a particle accelerator synchrotron radiation source to take a deeper look at the chemical composition of melanosomes in fossil samples of Tully's monster and modern vertebrates and invertebrates. The particle accelerator overloads the sample with intense bursts of radiation, causing the elements within it to become identifiable. Each element has its own specific X-ray signature.

When analyzing the zinc to copper ratio in the Tully monster's eyes, it was determined that the creature was more similar to invertebrates than to vertebrates, contrary to what previous research had claimed. Specifically, the researchers discovered that the Tully monster's eyes contained a different type of copper than those found in vertebrates. However, the study authors argue that although this unusual creature is different from vertebrates, it is also not identical to invertebrates. Thus, the new study supports the idea that the Tully monster is not a vertebrate, but at the same time denies it the right to belong to the invertebrates. It seems scientists are back to square one with the Tully monster, and its mystery remains a mystery.