Fossilized early vertebrates -- because of a lack of bones or cartilage -- has proven nearly nonexistent.

The Utah landscape is dotted with dinosaur fossils. But one of the smallest of those dots, a three-quarter inch fossil, could provide some of the largest clues into the history of animal vertebrates.

Harvard paleontologists Rudy Lerosey-Aubril and Javier Ortega-Hernández dug up what they believe is a 500-million-year-old relic that can help solve the mystery of the origins of vertebrates. The pair shared their discovery of the Nuucichthys rhynchocephalus fossil, which they found in Utah's Drumian Marjum Formation in a study published in Royal Society Open Science and why they believe it holds global consequence.

Considered the first soft-bodied vertebrate from North America's dino fossil-rich Great Basin, they wrote in the study, this newly found Nuucichthys fossil is characterized by its finless torpedo-shaped body that includes a snout-like head with anterolateral eyes.

The 500-million-year-old primitive fish without bones or teeth has surprisingly advanced anatomical features. "Based on the eye orientation and absence of fins," the study authors wrote about the fossil, "we tentatively reconstruct Nuucichthys as a pelagic organism with limited swimming abilities."

The state's geological record is key in documenting the dawn of animal life, the scientists said. "Utah is home to an incredible paleontological archive," Lerosey-Aubril said in a discussion published by the National History Museum of Utah. "The beehive state is renowned for its spectacular dinosaurs, but fewer people know that it is also one of the world's most important regions for studying the origins of animal life."

The researchers said that the newly found fossil shows the evolution of animal life during the Cambrian Explosion. "This time interval saw the emergence of animals," Lerosey-Aubril said. "That's really the moment when these organisms became prominent components of marine ecosystems."

But it's hard to track in the fossil record, since early vertebrates lacked the bones and cartilage needed to leave fossils behind long after their deaths.

Lerosey-Aubril said that he believes the Nuucichthys possessed characteristics of modern vertebrates, but not all of them, a type of "stem group species" that may have given animals a start. He cited muscle organization, complex eyes, and structured branchial cavity that may have housed operations needed for breathing and filtering food as key clues. Of course, the lack of fins adds to the intrigue on this fishy find that may have helped begin the path of developing anatomical traits.

With so few fossilized finds like the Nuucichthys discovery, this is the first that actually confirms the absence of fins in stem-group vertebrate. A previous discovery in Canada hinted at the absence but wasn't a high-quality enough specimen to answer the question with certainty. "These small early fish were clearly not cruiser-type simmers," Lerosey-Aubril said. "Instead, they likely lived in the upper layers of the sea, occasionally using body undulation to reach plankton-rich areas."

The scientists now hope that through this Utah discovery, they can help reconstruct pieces of the Cambrian Explosion, a time some believe contained rapid growth of animal diversity. The new find is one of several thousand Cambrian fossils the Utah museum has in its collection, though, so help could be on the way.