Search results
Results from the WOW.Com Content Network
The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an external skeleton . In order to keep growing, they must go through stages of moulting , a process by which they shed their exoskeleton to reveal a new one.
Panarthropoda is a proposed animal clade containing the extant phyla Arthropoda, Tardigrada (water bears) and Onychophora (velvet worms). [3] Panarthropods also include extinct marine legged worms known as lobopodians ("Lobopodia"), a paraphyletic group where the last common ancestor and basal members of each extant panarthropod phylum are thought to have risen.
Arthropod species (IUCN, 2016-2) 9470 extant species have been evaluated; 6580 of those are fully assessed [a] 4478 are not threatened at present [b] 2100 to 4990 are threatened [c] 83 to 169 are extinct or extinct in the wild: 81 extinct (EX) species [d] 2 extinct in the wild (EW) 86 possibly extinct [CR(PE)] 0 possibly extinct in the wild [CR ...
As of July 2016, the International Union for Conservation of Nature (IUCN) listed 394 critically endangered arthropod species, including 86 which are tagged as possibly extinct. [1] [2] 4.1% of all evaluated arthropod species are listed as critically endangered. The IUCN also lists three arthropod subspecies as critically endangered.
Additionally 2875 arthropod species (30% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status. As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN. [ 2 ]
It was not applied strictly to the arthropod until the 1580s. The ultimate meaning of the word is unknown. [3] [4] The name Cirripedia comes from the Latin words cirritus "curly" from cirrus "curl" [5] and pedis from pes "foot". [6] The two words together mean "curly-footed", alluding to the curved legs used in filter-feeding. [7]
Of all evaluated arthropod species, 4.1% are listed as near threatened. The IUCN also lists six arthropod subspecies as near threatened. No subpopulations of arthropods have been evaluated by the IUCN. This is a complete list of near threatened arthropod species and subspecies as evaluated by the IUCN.
Mollisonia is an extinct genus of Cambrian arthropod. 4 species had been described from North America and China. Studies suggest it is a basal member of Chelicerata, a group which includes horseshoe crabs and arachnids. [1] [2]