Scientists have uncovered a new species of chordate, a group that includes vertebrates like humans, in a surprising discovery from the Cambrian period, about 518 million years ago.
This remarkable find was made by Harvard research scientist Rudy Lerosey-Aubril and associate professor Javier Ortega-Hernández, and is detailed in their recent paper published in Royal Society Open Science.
The Cambrian period was a time of rapid animal diversification in Earth’s oceans, but chordate fossils from this era are quite rare.
This makes the discovery of Nuucichthys rhynchocephalus, the first soft-bodied vertebrate found in the Drumian Marjum Formation of the American Great Basin, especially significant.
The fossil was part of a collection held at the Museum of Natural History of Utah, a long-term partner of Harvard researchers.
Nuucichthys rhynchocephalus had a finless, torpedo-shaped body with several features characteristic of vertebrates.
According to Lerosey-Aubril, “Early vertebrates start to have big eyes and muscle blocks called myotomes, which we recognize in this fossil.” The species also had a rudimentary gill system, similar to larval fish, but lacked fins, indicating limited swimming abilities.
This new species is one of only four documenting the early evolutionary stage of vertebrates, making it one of humanity’s oldest relatives. Despite their similarities to larval fish, these early vertebrates didn’t have bones, which is why fossils like this are exceedingly rare.
The researchers speculate that Nuucichthys lived high up in the ocean and, lacking bones or shells, was prone to rapid decay, explaining its scarcity in the fossil record.
Ortega-Hernández highlights the significance of this find: “Understanding how the morphology evolved from the invertebrate type to the vertebrate type is difficult without fossils, and this new fossil tells us a little bit about that.” The discovery provides valuable insights into early vertebrate evolution and biodiversity, bridging gaps in our knowledge of this critical period.
Since 2022, an international team of paleontologists has been intensively investigating the Drumian Marjum site, led by Lerosey-Aubril and Ortega-Hernández. They believe that continued efforts may lead to the discovery of more specimens of Nuucichthys rhynchocephalus in the future.
This fascinating find not only sheds light on early vertebrate life but also underscores the importance of ongoing paleontological research in uncovering the mysteries of our planet’s distant past.
