It’s a mysterious aquatic creature that went extinct more than 300 million years ago. But if a person had been around to see this creature alive and swimming around in a river or lake, they may not have been able to believe their eyes. Scientists have dubbed it the Tully Monster, and it’s weird beyond belief.
The first fossil of the Tully Monster was found in 1955 in the Mazon Creek water beds located in Illinois. It was originally unearthed by amateur fossil hunter Francis Tully. He is now the namesake of the creature. Francis Tully brought his find to the Field Museum of Natural History. Scientists took one look at it and were completely baffled.
Weird Creature Features
After decades of research, the Tully Monster continues to defy classification. Researchers still aren’t even sure if this creature was a vertebrate (with a backbone) or invertebrate (without a backbone). It somewhat resembles what might be a giant slug. The problem is, everything is out of place. For example, Tully has two long appendages emerging from the location where the mouth should be. These long “arms” end in what looks like a pair of grasping claws.
Perhaps the strangest features of the Tully Monster are its eyes. They protrude from the stomach or middle portion of the creature on two long stalks. It has a pair of vertical fins situated on its tail. The creature also has a long proboscis (nose) with sharp teeth on each jaw, although if this was actually a fully formed jaw remains unknown.
Several more Tully Monster fossils have been found since the first in 1955. The largest so far is about 14 inches long. Other specimens were as small as three inches have been collected.
A Controversial Theory Emerges
A major breakthrough in identifying what kind of beast Tully might have been finally came in 2016. According to Nature magazine, a morphological study determined that Tully may have been a basal vertebrate. This means it had a backbone, or vertebral column, and a series of backbones that surrounded the spinal column.
It also has a skull surrounding a brain. Other examples of basal vertebrates are lungfish, tetrapods, paddlefish, sturgeons. Sharks and rays are more advanced or higher-order basal vertebrates.
The study which seemed to nail down the Tully Monster as a water-dwelling creature with a backbone is highly controversial, however. Not all scientists agree. They think its highly likely that the Tully Monster was more akin to an octopus or squid which have eyes that are partitioned and shaped in a way that is similar to Tully. These latter creatures do not have backbones.
High Technology Clues
More evidence that Tully was not a basal vertebrate was obtained from a high technology method of determining what elements exist within the fossil remains. To find these trace elements, the fossil is bombarded with X-rays. This causes tiny elemental molecules to become excited and emit a specific signature.
This method has determined that modern octopi and squids have a higher zinc-to-copper ratio in their eyes than do species with backbones. The bottom line is, the zinc-to-copper ratio in Tully was more similar to octopus and squid than sharks, rays, lungfish or sturgeon.
This is far from a settled matter, however. The debate about the true nature of the Tully monster rages on in the scientific community. One thing all researchers agree upon is that the Tully Monster was one of the strangest creatures ever to live on earth.
In 1989, the Tully Monster received a special honor. It was named the state fossil of the state of Illinois.