Scyliorhinus is a genus of catsharks in the family Scyliorhinidae. This genus is known in the fossil records from the Cretaceous period, late Albian age to the Pliocene epoch.
Ceratodontidae is an extinct family of lungfish with fossils known worldwide from the earliest Triassic to the Eocene.
Neoceratodus is a genus of lungfish in the family Neoceratodontidae. The extant Australian lungfish is the only surviving member of this genus, but it was formerly much more widespread, being distributed throughout Africa, Australia, and South America. Species were also much more diverse in body plan; for example, the Cretaceous species Neoceratodus africanus was a gigantic species that coexisted with Spinosaurus in what is now the Kem Kem Formation of Morocco. The earliest fossils from this genus are of Neoceratodus potkooroki from the mid Cretaceous (Albian-Cenomanian) Griman Creek Formation of Australia; remains from the Late Jurassic of Uruguay assigned to this genus probably do not belong to the genus.
Xanthidae is a family of crabs known as gorilla crabs, mud crabs, pebble crabs or rubble crabs. Xanthid crabs are often brightly coloured and are highly poisonous, containing toxins which are not destroyed by cooking and for which no antidote is known. The toxins are similar to the tetrodotoxin and saxitoxin produced by puffer fish, and may be produced by bacteria in the genus Vibrio living in symbiosis with the crabs, mostly V. alginolyticus and V. parahaemolyticus.
Mioceratodus is an extinct genus of lungfish in the family Neoceratodontidae, which also contains the extant Queensland lungfish. It is known only from Oligocene and Miocene-aged sediments in Australia, although phylogenetic evidence supports it having first diverged from its closest relative, Neoceratodus, during the Late Jurassic or Early Cretaceous period.
Paraceratodus is an extinct genus of prehistoric lungfish. Only one species, P. germaini, is known from the latest Permian or earliest Triassic period of Madagascar. Phylogenetic evidence supports it being the most basal member of the suborder Ceratodontoidei, which contains modern lungfish, and as with the rest of the order it likely diverged during the late Carboniferous.
The family Homolidae, known as carrier crabs or porter crabs, contains 14 genera of marine crabs. They mostly live on the continental slope and continental shelf, and are rarely encountered. Members of the Homolidae have their fifth pereiopods in a sub-dorsal position, which allows them to hold objects in place over the rear half of the carapace. The objects carried include sponges, black corals and gorgonians, and this behaviour may be a defence mechanism against predators. Some species have been observed carrying living sea urchins in a symbiotic relationship which allows them to benefit from the protection of the urchin's dangerous spikes.
Demania is a genus of crabs in the family Xanthidae, containing the following species:
Lophozozymus is a genus of crabs in the family Xanthidae, containing the following species:
Around 65 species of crab occur in the waters of the British Isles. All are marine, with the exception of the introduced Chinese mitten crab, Eriocheir sinensis, which occurs in fresh and brackish water. They range in size from the deep-water species Paromola cuvieri, which can reach a claw span of 1.2 metres, to the pea crab, which is only 4 mm (0.16 in) wide and lives inside mussel shells.
Danièle Guinot is a French biologist, an emeritus professor at the Muséum national d'histoire naturelle in France, known for her research on crabs.
Platymaia is a genus of crab in the family Inachidae, containing the following species:
Mathildellidae is family of crabs belonging to the superfamily Goneplacoidea, containing the following genera:
Neoceratodontidae is a family of lungfish containing Neoceratodus and the extinct Mioceratodus. It, Lepidosirenidae, and Protopteridae represent the only lungfish families still extant.
Leptomithrax is a genus of crabs in the family Majidae, first described by Edward J. Miers in 1876. They have been on Earth for 37.2 million years.
Ceratodontiformes is the only extant order of lungfish, containing the families Neoceratodontidae, Lepidosirenidae, and Protopteridae as well as many other extinct groups. Members of this group are the only lungfish known to have survived the Permian-Triassic extinction event. Although lungfish originated in marine environments, the Ceratodontiformes have been an exclusively freshwater group since the Carboniferous. This order was formerly considered the suborder Ceratodontoidei.
Goneplax is a genus of crabs, in the family, Goneplacedae, containing the following extant species:
Macraucheniopsis is an extinct genus of litoptern mammal belonging to the family Macraucheniidae from the Middle to Late Pleistocene of Argentina. It, along with Macrauchenia, Neolicaphrium, and Xenorhinotherium were among the youngest known genera of litopterns.
Gordonopsis mazupo is a species of deep-sea porter crab. It was discovered in the South China Sea in 2021 and described as a new species in 2024.
Gordonopsis is a genus of deep-sea porter crabs in the family Homolidae. The Homolidae are also known as carrier crabs or porter crabs for their fifth pereiopods, which they use to hold objects in place over the rear half of the carapace in a possible defence mechanism against predators. Species of Gordonopsis are found in deep waters of the Indo-West Pacific region. The genus was erected in 1995 by Danièle Guinot and Bertrand Richer de Forges.
