Xanthoidea is a superfamily of crabs, comprising seven families. Formerly, a number of other families were included in Xanthoidea, but many of these have since been removed to other superfamilies. These include Carpilioidea, Eriphioidea, Hexapodoidea, Pilumnoidea and Trapezioidea. Even in this reduced state, Xanthoidea remains one of the most species-rich superfamilies of crabs.
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.
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.
Dairoidea is a superfamily of crabs, comprising two families which each contain a single genus: Dairidae and Dacryopilumnidae (Dacryopilumnus) .
Xantho hydrophilus, the furrowed crab or Montagu's crab, is a species of crab from the family Xanthidae. It is yellowish-brown and grows to a carapace width of 70 mm (2.8 in). It is a nocturnal omnivore that lives in shallow marine waters from western Scotland to the Cape Verde Islands.
Paraetisus globulus is a species of crab in the family Xanthidae, the only species in the genus Paraetisus. It was described in 1933 by Charles Melbourne Ward.
Medaeus is a genus of crabs in the family Xanthidae, containing the following species:
Paramedaeus is a genus of crabs in the family Xanthidae, containing the following species:
Lobiactaea lobipes is a species of crabs in the family Xanthidae, the only species in the genus Lobiactaea.
Meractaea is a genus of crabs in the family Xanthidae, containing the following species:
Rata is a genus of crabs in the family Xanthidae, containing the following species:
Alainodaeus is a genus of crabs in the family Xanthidae, containing the following species:
Danielea moelensis is a species of crab in the family Xanthidae, and the only species in the genus Danielea.
Polydectus cupulifer is a species of crab in the family Xanthidae, and the only species in the genus Polydectus. Together with the genus Lybia, it forms the subfamily Polydectinae. It is found in the Indo-Pacific, ranging from Madagascar and the Red Sea in the west to Japan, Hawaii and French Polynesia in the east. P. cupulifer is densely covered with setae (bristles), and frequently carries a sea anemone in each chela (claw).
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 species:
Calvactaea tumida is a species of crabs in the family Xanthidae, the only species in the genus Calvactaea.
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:
