Paraetisus globulus | |
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Genus: | Paraetisus Ward, 1933 |
Species: | P. globulus |
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Paraetisus globulus Ward, 1933 | |
Paraetisus globulus is a species of crab in the family Xanthidae, the only species in the genus Paraetisus. [1] [2] It was described in 1933 by Charles Melbourne Ward. [3]
Thalassinidea is a former infraorder of decapod crustaceans that live in burrows in muddy bottoms of the world's oceans. In Australian English, the littoral thalassinidean Trypaea australiensis is referred to as the yabby, frequently used as bait for estuarine fishing; elsewhere, however, they are poorly known, and as such have few vernacular names, "mud lobster" and "ghost shrimp" counting among them. The burrows made by thalassinideans are frequently preserved, and the fossil record of thalassinideans reaches back to the late Jurassic.
The Ocypodidae are a family of semiterrestrial crabs that includes the ghost crabs and fiddler crabs. They are found on tropical and temperate shorelines around the world.
Hymenosomatidae is a family of crabs with some 110 described species in nearly 20 genera. The following genera are placed in the Hymenosomatidae:
Cancridae is a family of crabs. It comprises six extant genera, and ten exclusively fossil genera, in two subfamilies:
Retroplumidae is a family of heterotrematan crabs, placed in their own (monotypic) superfamily, Retroplumoidea.
The thumbnail crab, Thia scutellata, is a species of decapods, in the family of thiidae, whose carapace resembles a human thumbnail, a dense fringe of long hairs distinctly notched around the edge. Pale pink in colour with red to brown markings. It is found in the North Sea, north-east Atlantic and Mediterranean Sea. It is the only extant species in the genus Thia, although two fossil species are known. Their predators includes the atlantic cod.
Gecarcinucoidea is a superfamily of freshwater crabs. Its members have been grouped into families in various ways, with some authors recognizing families such as "Deckeniidae", "Sundathelphusidae", and "Parathelphusidae", but now only the family Gecarcinucidae is currently recognized.
Eubrachyura is a group of decapod crustaceans comprising the more derived crabs. It is divided into two subsections, based on the position of the genital openings in the two sexes. In the Heterotremata, the openings are on the legs in the males, but on the sternum in females, while in the Thoracotremata, the openings are on the sternum in both sexes. This contrasts with the situation in other decapods, in which the genital openings are always on the legs. Heterotremata is the larger of the two groups, containing the species-rich superfamilies Xanthoidea and Pilumnoidea and all the freshwater crabs. The eubrachyura is well known for actively and constantly building its own burrows. The fossil record of the Eubrachyura extends back to the Cretaceous; the supposed Bathonian representative of the group, Hebertides jurassica, ultimately turned out to be Cenozoic in age.
Cheiragonidae is a small family of crabs, sometimes called helmet crabs, placed in its own superfamily, Cheriagonoidea. It comprises three extant species, Erimacrus isenbeckii, Telmessus acutidens and Telmessus cheiragonus, there are no yet evidences of Cheiragonidae in the fossil record. Many of these crabs were formerly treated as members of the Atelecyclidae.
Tanaocheles is a genus of crabs, the only genus in the family Tanaocheleidae. It contains two species, T. bidentata and T. stenochilus. The two species were formerly placed in different families, and they were only shown to be related, and placed in a new subfamily, in 2000.
Actumnus is a genus of crabs in the family Pilumnidae. Alongside the 28 extant species, it has a fossil record extending back into the Miocene.
Pseudozioidea is a superfamily of crabs, formerly treated in the Eriphioidea, Carpilioidea, Xanthoidea, Pilumnoidea and Goneplacoidea. A number of fossils from the Eocene onwards are known from the family Pseudoziidae. Eleven genera are recognised in three families:
Palicoidea is a superfamily of crabs, comprising the two families Crossotonotidae and Palicidae. Together, they contain 13 genera, including two genera in the Palicidae known only from fossils. The two families were previously treated as two subfamilies in a Palicidae of wider circumscription.
Epialtidae is a family of crabs, containing the subfamilies:
Panopeus is a genus of crabs, containing these extant species:
Paraxanthias is a genus of crabs in the family Xanthidae, containing one exclusively fossil species and the following extant species:
Xanthias is a genus of crabs in the family Xanthidae, containing two exclusively fossil species and the following extant species:
Xanthodius is a genus of crabs in the family Xanthidae, containing one exclusively fossil species and the following extant species:
Atergatis is a genus of crabs in the family Xanthidae, containing the following species:
Zosimus is a genus of crabs in the family Xanthidae, containing the following species: