Researchers report that a 550-million-year-old Ediacaran organism, Spriggina floundersi, shows evidence of population-level “right-handedness.” The claim is based on fossil impressions preserved in South Australia and described as representing repeated directional behavior during the animal’s life. In the study, scientists examine more than 100 preserved specimens and look for consistent asymmetries in how the organism moved or turned, which they interpret as a directional preference rather than an individual-level trait.
The findings are presented as the earliest potential evidence that left-right behavioral patterns existed in the animal kingdom, predating later groups such as those associated with dinosaurs or mammals by hundreds of millions of years. The reports note that the organism is from the Ediacaran Period and lived in marine environments at the time.
While the conclusions are discussed as early evidence of handedness, the interpretation depends on linking fossil traces to specific aspects of behavior and neurology. Overall, the sources agree the fossil record suggests a consistent directional bias in Spriggina floundersi across a population, making it an important data point for the timing of left-right behavioral evolution.
