Shrimps’ ancient chain gang mystifies scientists

Lewis Smith, Environment Reporter Mysterious shrimp-like creatures from 525 million years ago have been identified as the first to exhibit collective behaviour. All but one of dozens of the fossilised creatures found by researchers were linked together in chains that had survived even sudden death. The reason for linking in chains is uncertain but researchers believe it is most likely the animals sought safety in numbers while migrating. Other animals, including trilobites, are known from their distribution patterns to have migrated during the Early Cambrian period but the chain fossils are the earliest to preserve a migration taking place. The closely interlocked chains were formed when one of the animals inserted its tail beneath the shell at the front of another. The ancient arthropods, a category of animals that includes... [read full story]