Fossil Crustaceans
Lobsters, shrimps, crabs, and isopods — crustaceans have dominated marine benthic environments for over 500 million years and left a rich fossil record in Jurassic and Cretaceous limestone.
Overview
Crustaceans — crabs, lobsters, shrimps, krill, barnacles, ostracods and more — are the arthropods of the sea. Their record runs from the Cambrian to today's dinner plate, with extraordinary preservation in fine-grained Lagerstätten.
Quick Facts
Key Characteristics
- •Two pairs of antennae and biramous (two-branched) limbs
- •Carapace covering the head/thorax in many groups
- •Growth by molting; many larval stages
- •Ostracods: bean-sized shells (valves) that are among the most abundant fossils on Earth
- •Decapods: five pairs of walking legs; crabs evolved multiple times from lobster-like ancestors
Fossil Record
Ostracod valves are so widespread they are standard microfossils; complete decapods occur in Solnhofen Limestone, Oxford Clay, Haitian and Italian Cretaceous Lagerstätten; Cenozoic deposits yield crab-rich shell beds.
Global Distribution
Global, in marine and continental sediments of the last 530 million years.
Evolutionary & Scientific Importance
Crustacean fossils carry deep-time ecology (predation, parasitism, hermiting), and ostracods are premier index microfossils for biostratigraphy and water-temperature reconstruction.