Ancient “lamp shells” – bottom-dwelling invertebrates that once ruled the oceans – may have used hundreds of bristle-like structures to “social distance” in a bid to improve their chances of survival, Chinese palaeontologists have discovered.
Their findings are based on a fossilised species of brachiopods – or clam-like marine animals – that was discovered in China’s southwestern Guizhou province.
The fossils, discovered embedded in rocks, were found to be arranged in a “checkerboard-like” pattern across what was once the sea floor.
Individuals of the extinct species Nucleospira calypta were likely to have used the flexible bristle-like structures – thinner than human hair – to help guide their movement and arrange their population to provide adequate space for filter feeding.
“We report exceptionally preserved soft, bristle-like structures (“setae”) on 436-million-year-old brachiopods, enabling analysis of ancient behaviour,” the team said in a paper published in the peer-reviewed journal Proceedings of the National Academy of Sciences on July 21.
Using advanced imaging and spatial analysis, the researchers determined that Nucleospira calypta formed a “highly regular” pattern of spacing that corresponded to about 1.5 to 2 times the length of their setae.