A new fossil discovery shows that tiny, shrimp-like invertebrates living 525 million years ago linked up into formations that resemble daisy chains, and researchers say this could be the earliest example yet of animals engaging in group behavior. The fossilized creatures were found in closely interlocked chains of up to 20 individuals, with the tail of one animal inserted into the carapace of the next.
The ancient arthropods, a category of animals that includes insects, crustaceans and spiders, lived in open water rather than remaining on the sea bed. When they died, possibly as a result of moving into water loaded with toxins or short of oxygen, they sank to the seabed, where they were covered in sediment [The Times]. Researchers can’t be certain why the arthropods joined together into chains, but their best guess is that the animals were in the middle of a migration when they perished.
