The shrimp-like fossil was discovered in the 1980s, and researchers knew almost nothing about it other than its species. It turned out even that was wrong, but the big story here isn’t as much the end as the means.
After a team of paleontologists, co-led by a Harvard scientist, used special X-ray imaging in 2018 to create a 3D rendering of the ancient specimen, they discovered the fossil was a completely unknown species that had lived sometime in the early Cambrian, approximately 518 million years ago. The creature they described was particularly fierce. Though only 2 centimeters long, it brandished 810 dagger-like spines that were divided among its 54 legs. It used them to shred prey, like worms, on the ocean floor.
The discovery was published this summer in BMC Evolutionary Biology and is one of the latest examples of a growing body of research opening new avenues in how scientists understand the early evolution of arthropods, all of it made possible by the use of the imaging technique called micro-computed tomography, or micro-CT.
The work is partially funded by the Harvard China Fund and has led to five papers in the past year and a half that have helped reveal new details of early Cambrian fossils. The features formerly had been undiscernible through more conventional methods; taken together, they are helping cast further light on why we have the species of spiders, crabs, butterflies, and other arthropods we do today.
“Usually, we can only see one side of the animal [because of the way these fossils are stuck on the rock on which they are preserved],” said Javier Ortega-Hernández, an assistant professor in the Harvard Department of Organismic and Evolutionary Biology and curator of invertebrate paleontology in the Museum of Comparative Zoology. “But, ideally, we want to get to the underside, which has all the juicy, lovely details.”
That is what Ortega-Hernández has been doing during the last five years in conjunction with Yu Liu, a paleobiology professor at Yunnan University in China, using micro-CT.