Mysterious 300 million-year-old ‘Tully monster’ may not be the thing scientists thought it was
Mysterious 300 million-year-old “Tully monster” may not be the thing scientists thought it was – as new research reveals it wasn’t a vertebrate after all
- Tullimonstrum, also known as the Tully monster, lived 300 million years ago
- It has stunned scientists since fossils were first discovered 60 years ago
- A discovery in 2016 of stiffened cartilage classified Tully as a predatory vertebrate
- Now University College Cork researchers believe it was not a vertebrate
The mysterious Tully monster has probably not been a vertebrate – despite its hard cartilage that has been reversed – scientists claim, after discovering unusual elements in its fossilized eyes.
Tullimonstrum, also known as the Tully monster, which lived 300 million years ago, has stunned scientists since fossils were first discovered 60 years ago.
An earlier discovery in 2016 showed that Tully had a stiffened cartilage rod that supported his body and gills – suggesting that the creatures were predatory vertebrates, similar to some primitive fish.
The Tullimonstrum was first discovered in the 1950s by fossil collector named Francis Tully when the first fossils were found in fossil beds of Mazon Creek in central Illinois
But now University College Cork researchers believe that this was not the case after studying chemicals that were present in the animal’s eyes.
WHAT WAS THE FULL SAMPLE?
The Tullimonstrum was first discovered in the 1950s by fossil collector named Francis Tully when the first fossils were found in fossil beds in Mazon Creek in central Illinois.
The Tully monster, or Tullimonstrum gregarium, is believed to have been a soft sea creature that lived in muddy coastal waters in what is now Illinois.
They would have become about a foot long (10 cm) with a slender segmented body.
His eyes were at each end of a long stiff beam over the top of his head and it had a tail fin.
Strangely enough, it had jaws at the end of a long trunk, suggesting it might eat food hidden deep in the silt of the estuary or in rocky corners and holes.
In his body it had a stiff cartilage rod, known as a notochord, which helped to give it structure.
With the help of a particle accelerator, the proportions of elements in contemporary vertebrates and the eyes of invertebrates could be determined. They could make a comparison with the old Tullimonstrum.
They discovered that a ratio of zinc to copper in the melanosomes of the eyes resembled that of modern invertebrates more than that of vertebrates.
By bombing specimens with bursts of radiation, the scientists were able to ‘excite’ elements inside – in this state, each element issues a characteristic X-ray that allows them to figure out which elements make up the eyes.
Dr. Chris Rogers Postdoctoral researcher in Paleobiology, University College Cork, who led the study wrote in The conversation: “The chemistry of Tully’s eyes and the ratio of zinc to copper was more similar to that of invertebrates than vertebrates.
“This suggests that the animal might not be a vertebrate, which contradicted previous attempts to classify it.”
The research team also discovered that the fossil’s eyes contain a different type of copper than those of the modern invertebrates that they studied – which prevented them from classifying it.
Scientists previously believed that the Tully monster (fossils shown above) must have been a vertebrate because of the pigments they discovered in his eyes. The melanosome pigments were found in both spherical and elongated forms, or sausages and meatballs (pictured lower right), which are found only in vertebrates. This has since been disputed
The Tullimonstrum fossil, a cross-section of the animal, can be seen. They would have become about a foot long (10 cm) with a slender segmented body
Dr. Rogers added: ‘Although our work adds weight to the idea that Tully is not a vertebrate, it also clearly does not identify an invertebrate.
‘Where do we go from here? A broader analysis of the chemistry of melanosomes and other pigments in the eyes of a wider range of invertebrates would be a good next step.
WHAT ARE VERTEBRATES?
A vertebrate is an animal with a spinal cord or cartilage covered spinal cord.
The term comes from the word vertebrae, the bones that make up the spine.
Animals without spinal cord or cartilage covered spinal cord are called invertebrates.
Vertebrates are birds, fish, amphibians, reptiles and mammals.
“This can help to further limit the group of animals to which Tully belongs.”
Previous research conducted by the University of Leicester professor of geology Sarah Gabbott in 2016 also studied the eyes of the Tully, but came to a different conclusion.
When observing melanosomes, the researchers concluded that the animal was a vertebrate, since the melanosomes were presented in both spherical and elongated forms – “such as microscopic meatballs and sausages.”
Dr. Gabbot said: “Only vertebrates have two different forms of melanosome, which means that this is the first unambiguous evidence that Tullimonstrum is a member of the same group of animals as we, the vertebrates.”
The most recent research: Synchrotron X-ray absorption spectroscopy of melanosomes in vertebrates and cephalopods: implications for the affinity of Tullimonstrum by Christopher S. Rogers, Timothy I. Astrop, Samuel M. Webb, Shosuke Ito, Kazumasa Wakamatsu and Maria E. McNamara, has been published through The Royal Society.
An illustration shows what Mazon Creek looked like 300 million years ago, complete with Tully monsters (the two small swimming creatures), a large shark and a relative of a salamander. The new study claims that the identity of the samples is still in the air
With a strange tubular body, eyes on stems and a long trunk-like mouth, the Tully monster (artist’s impression depicted) has stunned scientists for decades
THE FULL MONSTER AND ITS BACKBONE
In 2016, experts said the Tully monster was probably a predatory vertebrate associated with lamprays.
Paleontologists at Yale University showed that the creature had a stiff rod of cartilage that supported his body and gills. This means that it was a predatory vertebrate, similar to primitive fish.
US Geological Survey sea lamprey expert Dr. Nick Johnson demonstrates the edge of fabric, called a rope, along the back of an adult male sea lamprey
Victoria McCoy, a paleontologist who conducted the research at Yale Univesity, now based at Leicester University, analyzed the morphology and conservation of the animal.
With the help of powerful analytical techniques, such as synchrotron elemental mapping, which chart the physical characteristics illuminated by the chemistry of the fossil, she was able to unravel its characteristics.
Her team discovered that the animal had a vestigial spinal cord, known as a notochord, and gills that had not previously been identified in the fossils.