mated says Brett. "The queues or chains may record migration. In the absence ofeyes, the trilobites must have found other ways to stay together in their migratory caravan. Possibly they used chemical signals, or perhaps each animal felt for the individual in front using their antennac. Dunng these particular migrations, the trilobites evidently met with disaster. Perhaps they were smothered by a pocket water exceptionally low in oxygen, which suffocated them. On today's scafloor, some species of lobster form similar sorts of chains. They often migrate further offshore into deeper water in the run-up to winter. perhaps to escape strong winter storms that can churn up sediment in shallower settings But exactly why the lobsters choose to migrate in chains, rather than individually, is a bit of an enigma"The queues may help reduce drag on individuals," says Brett. Individuals in chains may also help to protect one another[from predators] "Examples indicating some kind of integrative, 'social' behaviour are relatively rare in the fossil record," says Derek Siveter at the University of Oxford in the UK. "This example of Trimerocephalus trilobites very usefully increases our knowledge of such occurrences.