Fossils of tiny, horseshoe-shaped creatures that inched along the ocean floor in single-line formations some 480 million years ago reveal the earliest known collective animal behaviour, researchers have found. Like all arthropods — a phylum that includes insects, centipedes, spiders and crustaceans — trilobites had a segmented body and an exoskeleton. “We are talking about the oldest display of organised collective behaviour in such a precise manner,” co-author Abderrazak El Albani, a scientist at France’s National Centre for Scientific Research, told AFP. Group behaviour among animals — schools of fish, flocks of birds, herds of antelope — has been exhaustively studied by biologists, but little is known about when or how it originated. “To exhibit collective behaviour, one needs an adapted nervous system that can pass signals from one individual to another,” he added.

Source: The Hindu October 19, 2019 16:30 UTC