The history of a 300-million-year-old fossil has been rewritten after scientists discovered it does not belong to the world’s oldest octopus, as previously thought.
In fact, it belongs to an animal related to the modern nautilus, which has tentacles and an external shell, according to a study published in the journal Proceedings of the Royal Society B.
“Basically, we use a wide selection of new analytical techniques to discover hidden anatomical features in the rock,” he told CNN on Thursday the study’s lead author, Thomas Clements, professor of invertebrate zoology at the University of Reading, England.
“And we were able to determine that it is not an octopus, but a nautiloid (a family of molluscs) in an advanced state of decomposition, related to modern nautiluses.”
The fossil, called Pohlsepia mazonensis, was found at the Mazon Creek archaeological site,
Paleontologists had long been intrigued by the fossil, as it is much older than the second oldest known octopus, which dates back to around 90 million years.
Clements explained that the animal had been decomposing for weeks before it was buried, which gave its fossil an octopus-like appearance, leading many scientists to conclude that octopuses
However, others questioned whether this was actually the case, as certain features, such as the length and shape of the arms, did not match what would be expected, Clements said.
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As a result, he decided to re-examine the fossil using new scientific techniques that were not available when the first analysis was published in 2000.
“We used a wide range of new techniques,” he said, including using a scanning electron microscope and carrying out geochemistry work.
But the fossil continued to refuse to reveal its true identity.
“We weren’t getting anywhere,” Clements said. “I was quite frustrated.”
Everything changed when a colleague invited him to scan the fossil using synchrotron imaging, a technique described by the University of Reading as using beams of light brighter than the sun. This technique “generates the most powerful X-rays in the world,” Clements explained.
“It revealed anatomical features that were hidden just below the surface of the rock, so that you can’t see them visually when looking at the fossil,” Clements said.
The team found a radula, a food structure with rows of teeth. There were at least 11 teeth per row in the fossil, while octopuses have just seven or nine, according to a statement from the University of Reading.
“It was these tiny teeth that we found that allowed us to identify that it was not an octopus,” he added.
Clements said the research demonstrates the power of new technologies to advance our scientific understanding.
“Not only are they becoming more accessible, they are also becoming cheaper, and this is revolutionizing paleontological investigations,” he said, highlighting the use of synchotrons to discover ancient proteins and biomolecules, and engineering techniques originally designed to test building materials to determine the strength of a dinosaur’s bite.
“A lot of people think of paleontology as a very old-fashioned science,” Clements said. “But we’re actually incredibly innovative science.”
