Eocarcinoidea
Encyclopedia
Eocarcinoidea is a family of fossil
decapod
crustacean
s. Formerly thought to be the earliest true crab
s, they are now thought to be the oldest members of the Anomura
. Two species are included, each in its own family: Eocarcinus praecursor
(Eocarcinidae) and Platykotta akaina
(Platykottidae).
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
decapod
Decapoda
The decapods or Decapoda are an order of crustaceans within the class Malacostraca, including many familiar groups, such as crayfish, crabs, lobsters, prawns and shrimp. Most decapods are scavengers. It is estimated that the order contains nearly 15,000 species in around 2,700 genera, with...
crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s. Formerly thought to be the earliest true crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s, they are now thought to be the oldest members of the Anomura
Anomura
Anomura is a group of decapod crustaceans, including hermit crabs and others. Although the names of many anomurans includes the word crab, all true crabs are in the sister group to the Anomura, the Brachyura .-Description:The name Anomala reflects the unusual variety of forms in this group;...
. Two species are included, each in its own family: Eocarcinus praecursor
Eocarcinus
Eocarcinus praecursor is a Jurassic species of decapod crustacean, sufficiently distinct from its relatives to be placed in its own family...
(Eocarcinidae) and Platykotta akaina
Platykotta
Platykotta akaina is a species of decapod crustacean from the Triassic of the United Arab Emirates. It is the oldest known fossil from the infraorder Anomura, and is most closely related to Eocarcinus praecursor.-Stratigraphy:The holotype of P...
(Platykottidae).