When it comes to the bizarre organisms discovered in the Burgess Shale, a collection of amazing Cambrian fossils buried in the Canadian Rockies, none has been nearly as captivating as Opabinia, a monster that has captivated scientists for more than a decade. Moreover, with five compound eyes and a trunk-like nozzle that culminated in a claw, Opabiania seemed extraterrestrial, rather than a swimmer in Earth’s waters some 500 million years ago as had been previously thought.
Stephen Jay Gould, evolutionary scientist and author of “Wonderful Life,” a best-selling book on the Burgess Shale, referred to Opabinia as a “strange marvel” and claimed it belonged in the same pantheon of evolutionary icons as Archaeopteryx, Tyrannosaurus rex, and archaic human predecessors.
Opabinia, on the other hand, has remained cloaked in evolutionary mystery due to a maddening scarcity of fossil evidence. The majority of Opabinia specimens were gathered more than a century ago, and the critter has never been discovered anywhere else in the world save in the Burgess Shale region.
It was for this reason that palaeontologist Stephen Pates was intrigued when he came upon an unusual fossil held at the Natural History Museum at Kansas University in 2017. As a PhD student, Dr. Pates was investigating the variety of radiodonts, which were prehistoric predators with grabbing, claw-like appendages that lived during the Cambrian period. The ghostly orange impression in front of him, on the other hand, lacked the distinctive appendages.
In western Utah, the specimen had been discovered, and it featured zigzagging body flaps and a tail bursting with enough spikes to make a Stegosaurus envious. Even though the creature’s characteristics were eerily similar to Opabinia, its badly preserved head was nothing more than a bloody smear, concealing the creature’s proboscis and a bountiful number of eyes.
The Cambrian creature’s identification was determined via a collaborative effort between Dr. Pates and numerous scholars at Harvard University, where he worked as a postdoctoral researcher, who ran the fossil through a range of phylogenetic tests to identify its identity. 125 of the fossil’s characteristics were matched up with more than 50 families of extant and ancient arthropods, and extensive evolutionary trees were constructed.
In the words of Joanna Wolfe, a Harvard University research associate and co-author of the new research, the evolutionary trees allowed the team to rule out radiodonts and come to the conclusion that the new fossil was most likely closely related to Opabinia, one of the Burgess Shale’s lonely wonders.
Identified in a report published Wednesday in Proceedings of the Royal Society B, the authors described the fossil as just the second opabiniid ever unearthed, making it a significant find. They named the new species Utaurora comosa after Aurora, the Roman goddess of the morning, who changed her lover into a cicada — one of the many arthropods that appeared after Utaurora. Utaurora comosa is the Latin term for the cicada.
The researchers feel that Utaurora is a crucial precursor to the development of insects and crustaceans, despite the fact that the animal still seems more foreign than an arthropod. As previously stated by Dr. Pates, the opabiniid family was one of the earliest groups to have backward-facing mouths, and its furrowed flaps were a prelude to segmentation, both of which are widespread features of contemporary arthropods, including cockroaches.
It would, on the other hand, be unlike any arthropod that exists now. Utaurora, with its flaps and spiky tail fan, undulated through an ancient sea, possibly using its proboscis to drive food into its mouth as it moved through the water. Despite the fact that the two species seemed to be identical, there were significant distinctions between them. Although the younger Utaurora had more spikes on its tail than the older one, at little over 1 inch in length, it was only half the size of Opabinia’s body.
Researchers think that this finding places Opabinia in perspective, demonstrating that one of the planet’s most bizarre organisms was more than simply a one-hit wonder in the first place. According to Dr. Pates, “They were a part of the greater picture of what was going on and not just this bizarre curiosity.”
However, Dr. Wolfe, who grew up reading “Wonderful Life,” says that the minuscule sea creature’s enthralling description of Opabinia was a catalyst for her paleontological career. While Opabinia is no longer considered unique, Dr. Wolfe says the minuscule sea creature’s description is no less captivating.
