Ecdysis is the moulting of the cuticle in many invertebrates of the clade Ecdysozoa. Since the cuticle of these animals typically forms a largely inelastic exoskeleton, it is shed during growth and a new, larger covering is formed. The remnants of the old, empty exoskeleton are called exuviae.
The class Heterotardigrada includes tardigrades that have cephalic appendages and legs with four separate but similar digits or claws on each. 444 species have been described.
Eutardigrada are a class of tardigrades (Tardigrada) without lateral appendices. Primarily freshwater bound, some species have secondarily gained the ability to live in marine environments (Halobiotus). By cryptobiosis many species are able to live temporarily in very dry environments. More than 700 species have been described.
Tardigrades, known colloquially as water bears or moss piglets, are a phylum of eight-legged segmented micro-animals. They were first described by the German zoologist Johann August Ephraim Goeze in 1773, who called them Kleiner Wasserbär. In 1777, the Italian biologist Lazzaro Spallanzani named them Tardigrada, which means "slow steppers".
Hypsibius dujardini sensu lato is a species complex of tardigrade in the class Eutardigrada. A member of this complex, Hypsibius exemplaris, is widely used for various research projects pertaining to evolutionary biology and astrobiology.
Hypsibius is a genus of tardigrades in the class Eutardigrada.
Acutuncus is a genus of tardigrades containing a single species, Acutuncus antarcticus. Tardigrades, which are eight-legged micro-animals, are commonly referred to as water bears or moss piglets and are found all over the world in varying extreme habitats. First discovered in 1904 and originally named Hypsibius antarcticus, Acutuncus antarcticus is the most abundant tardigrade species in Antarctica.
Cucumericrus decoratus is a species of putative radiodont known from a few poorly preserved specimens. Only fragments of trunk cuticle and corresponded appendages had been revealed, while important radiodont features such as frontal appendages are unknown in this species. The trunk cuticle possess irregular wrinkles and may had been soft in life. Each of the trunk appendage compose of a dorsal flap-like element and a ventral stubby leg with unknown distal region, structurally comparable to the trunk appendages of gill lobopodians and euarthropod biramous appendages. The legs have been interpreted as somewhere between annulated lobopod legs and segmented arthropod legs.
Milnesium antarcticum is a species of Eutardigrades in the family Milnesiidae. This species differs from its cogenerate species mainly by proportions of its claws and buccopharyngeal apparatus.
Milnesium almatyense is a species of Eutardigrades in the family Milnesiidae. This species differs from its cogenerate species mainly by proportions of its claws and buccopharyngeal apparatus.
Milnesium asiaticum is a species of Eutardigrades in the family Milnesiidae. This species differs from its cogenerate species mainly by proportions of its claws and buccopharyngeal apparatus.
Milnesium reductum is a species of Eutardigrades in the family Milnesiidae. This species differs from its cogenerate species mainly by proportions of its claws and buccopharyngeal apparatus.
Milnesium longiungue is a species of Eutardigrades in the family Milnesiidae. This species differs from its cogenerate species mainly by proportions of its claws and buccopharyngeal apparatus.
Peripatopsis lawrencei is a species of velvet worm in the Peripatopsidae family. This species has 18 pairs of legs: 17 pregenital leg pairs plus one last pair that is strongly reduced and without claws or spinous pads. This species is restricted to the Theewaterskloof-Overstrand region of South Africa.
The Overberg velvet worm is a species of velvet worm in the Peripatopsidae family. This species usually has 19 pairs of legs: 18 pregenital leg pairs plus one last pair that is strongly reduced and without claws or spinous pads. Some specimens, however, have only 18 leg pairs. This species is limited to the Overberg region of South Africa.
Diogmites is a genus of mainly neotropical flies in the family Asilidae or robber flies.
Macrobiotus shonaicus is a species of tardigrade in the family Macrobiotidae. As of 2018 it is only known from its type locality: Tsuruoka, Japan. The species description was published in 2018. The insides of their first three pairs of legs have a slight fold above their claws, and their eggs have processes whose terminal discs split off into thin filaments.
Hypsibius marcelli is a species of tardigrade in the class Eutardigrada. The species from described from brackish water on Tierra del Fuego. The species also has a disjunct Gondwanan distribution, reported from New Zealand.
Hypsibius septulatus is a species of tardigrade in the class Eutardigrada. The species is only known to be found in Peru. Hypsibius septulatus has unsculptured cuticles with around 22 dorsal undulations. It has two macroplacoids and a septulum on the first three pair of legs.
