Ancient Worm With a Right Turn
The study, led by researchers at the American Museum of Natural History, Florida State University, Harvard University, and the University of California, Riverside, examined more than 100 exceptionally preserved fossils of Spriggina floundersi from Nilpena Ediacara National Park and the South Australia Museum. The creature lived during the Ediacaran Period, roughly 550 million years ago, and is one of the earliest known animals with bilateral symmetry — a body plan featuring distinct front and back, left and right sides. phys.org miragenews.com
The team found that roughly twice as many specimens appeared bent to the left as to the right in the rock. Because the fossils preserve mirror-image impressions of the original animals, a leftward bend in stone represents an animal that bent to the right in life. miragenews.com newscientist.com
“When we talk about being right-or-left-handed, most people likely think about how they hold a pencil or kick a soccer ball. But our research shows that an animal without hands or feet, living over 500 million years ago, may have had its own version of handedness,” said lead author Scott Evans, assistant curator of invertebrate paleontology at the Museum. miragenews.com
What Handedness Tells Us About Ancient Brains
The discovery carries implications beyond locomotion. In living animals, consistent side preferences are associated with complex nervous systems. Evans noted that “living animals with this sort of handedness, from insects to octopi to birds and mammals, have complex sensory abilities,” suggesting that Spriggina’s nervous system may have been more advanced than its ancient origins would imply. newscientist.com miragenews.com
“It’s a reminder that some of the traits we take for granted today have incredibly ancient origins,” said study coauthor Mary Droser, a paleontologist at UC Riverside. miragenews.com
A Window Into Early Animal Life
Spriggina is the state fossil of South Australia, named for Reg Sprigg, who first recognized the Ediacara biota in the Australian outback more than 75 years ago. The Ediacaran Period, spanning roughly 635 to 538 million years ago, marks the era when microscopic life first evolved into multicellular organisms large enough to see with the naked eye and capable of behaviors including movement. The research was supported in part by a NASA Exobiology grant. eurekalert.org phys.org miragenews.com
