| Palaeopalaemon Temporal range: | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Crustacea |
| Class: | Malacostraca |
| Order: | Decapoda |
| Family: | † Palaeopalaemonidae Brooks, 1962 |
| Genus: | † Palaeopalaemon Whitfield, 1880 |
| Species: | †P. newberryi |
| Binomial name | |
| †Palaeopalaemon newberryi Whitfield, 1880 | |
Palaeopalaemon is an extinct genus of the oldest lobster-like aquatic decapod crustaceans, containing the species Palaeopalaemon newberryi. [1]
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen), usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers. They first appeared during the Jurassic Period.
The Decapoda or decapods are an order of crustaceans within the class Malacostraca, including many familiar groups, such as crabs, lobsters, crayfish, shrimp and prawns. Most decapods are scavengers. The order is estimated to contain nearly 15,000 species in around 2,700 genera, with around 3,300 fossil species. Nearly half of these species are crabs, with the shrimp and Anomura including hermit crabs, porcelain crabs, squat lobsters making up the bulk of the remainder. The earliest fossil decapod is the Devonian Palaeopalaemon.
Decapod may refer to:
Reptantia is a clade of decapod crustaceans named in 1880 which includes lobsters, crabs and many other well-known crustaceans.
Pleocyemata is a suborder of decapod crustaceans, erected by Martin Burkenroad in 1963. Burkenroad's classification replaced the earlier sub-orders of Natantia and Reptantia with the monophyletic groups Dendrobranchiata (prawns) and Pleocyemata. Pleocyemata contains all the members of the Reptantia, as well as the Stenopodidea, and Caridea, which contains the true shrimp.
The Achelata is an infra-order of the decapod crustaceans, holding the spiny lobsters, slipper lobsters and their fossil relatives.
Anomura is a group of decapod crustaceans, including hermit crabs and others. Although the names of many anomurans include the word crab, all true crabs are in the sister group to the Anomura, the Brachyura.
Porcelain crabs are decapod crustaceans in the widespread family Porcellanidae, which superficially resemble true crabs. They have flattened bodies as an adaptation for living in rock crevices. They are delicate, readily losing limbs when attacked, and use their large claws for maintaining territories. They first appeared in the Tithonian age of the Late Jurassic epoch, 145–152 million years ago.
Astacidea is an infraorder of decapod crustaceans including lobsters, crayfish, and their close relatives.
Glypheidea is an infraorder of lobster-like decapod crustaceans, comprising a number of fossil forms and the two extant (living) genera Neoglyphea and Laurentaeglyphea: The infraorder was thought to be extinct until a living species, Neoglyphea inopinata, was discovered in 1975. They are now considered "living fossils", with over 256 fossil species discovered, and just two extant species.
Nephropoidea is a superfamily of decapod crustaceans. It contains the true lobsters in the Nephropidae, and three fossil families: Chilenophoberidae, Protastacidae and Stenochiridae. Their closest relatives are the reef lobsters.
Polychelida is an infraorder of decapod crustaceans. Fossil representatives are known dating from as far back as the Upper Triassic. A total of 38 extant species, all in the family Polychelidae, and 55 fossil species have been described.
Eocarcinus praecursor is a Jurassic species of decapod crustacean, sufficiently distinct from its relatives to be placed in its own family (Eocarcinidae). Often considered the oldest true crab, it was considered by a 2010 study to be an early member of the Anomura. However, a reanalysis in 2020 again found it to be the earliest known stem-group crab.
Tetrachela raiblana is an extinct species of polychelid crustacean from the Late Triassic. It is the only species in the family Tetrachelidae. It is distinguished from most other polychelids, including all the extant Polychelidae, by the retention of the diaeresis (divisions) of the uropodal exopods.
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The larvae of crustaceans often bear little resemblance to the adult, and there are still cases where it is not known what larvae will grow into what adults. This is especially true of crustaceans which live as benthic adults, more-so than where the larvae are planktonic, and thereby easily caught.
Aciculopoda is an extinct prawn which existed in what is now Oklahoma approximately 360 million years ago. It was described in 2010 on the basis of a single fossil from Oklahoma. The single species, Aciculopoda mapesi, was named by Rodney Feldmann and Carrie Schweitzer in honour of Royal Mapes, a paleontologist who discovered the type specimen. It is only the third unambiguous fossil decapod from before the Mesozoic.
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.
Eryma is a genus of fossil lobster-like crustaceans, containing 44 species.
Crustaceans form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. Some crustaceans are more closely related to insects and the other hexapods than they are to certain other crustaceans.
Palinurina is an extinct genus of crustaceans, belonging to the decapods. These animals lived between the Lower Jurassic and the Upper Jurassic and their fossils can be found in Europe. This crustacean is considered one of the oldest lobsters.