High species diversification can be traced to the Jurassic and Cretaceous periods, which coincides with the rise and spread of modern coral reefs (scleractinia), a key habitat for the decapods.[3] Despite the inferred early origin, the oldest fossils of the group such as Palaeopalaemon only date to the Late Devonian.[4]
Crabs exhibit a complex social behavior pattern. Using their pincers they communicate with each other. They display aggression and usually males contest with each other for access to females. They even fight among themselves for hiding holes and caves. They work together for providing their family with food and protection. During mating season they find comfortable places for the females to release eggs.
Lobsters are loners and are usually found living singly in burrows and under rocks. They do have a rather unique feature in that lobsters do not die due to aging. They become stronger and more fertile with age due to the presence of enzyme telomerase (repairs DNA sequences). Thus lobsters continue to live until caught, injured or inflicted by disease.
