Velvet worm
The velvet worms (Onychophora — literally "claw bearers") are a minor panarthropod phylum.
| Velvet worms | |
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| A member of the Peripatidae family | |
| Scientific classification | |
| Kingdom: | |
| Superphylum: | |
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| Phylum: | Onychophora
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There are two families and about 200 species. All living species live on land, in moist or wet tropical areas.
The two living families are the Peripatidae and the Peripatopsidae. They show a peculiar distribution, with the peripatids being mainly equatorial and tropical, while the peripatopsids are all found in what used to be Gondwana.[1]
The segmented worm-like organisms have tiny eyes, "fur", antennae, multiple pairs of legs, and slime glands. The group is thought to be related to arthropods. They prey on smaller animals such as insects, which they catch by squirting a sticky slime.
Possible fossil history
Fossils from the early Cambrian bear a striking resemblance to the velvet worms. These fossils, known as the lobopods, were marine. They were a clade from which arthropods, tardigrades, and Onychophora arose.[2][3] They are found in the Cambrian,[4] Ordovician (possibly),[5] Silurian,[6] and Pennsylvanian[7] periods.
Historically, all fossil Onychophora and lobopods were lumped into the taxon Xenusia. However, few of the Cambrian fossils have features that definitely unite them with the Onychophora.[8] The exceptions are Hallucigenia and Collinsium ciliosum, which have distinctly onychophoran-like claws.[2]
Velvet Worm Media
- Peripatoides novaezealandiae 272115998.jpg
Peripatoides novaezealandiae flipped upside down
- Ooperipatellus viridimaculatus 34495501.jpg
Ooperipatellus viridimaculatus
- Peripatopsis overbergiensis 45218773.gif
Peripatopsis overbergiensis squirting its slime
- Euperipatoides claw pair.tif
A pair of claws from the onychophoran Euperipatoides kanangrensis, blue mountains, New South Wales, showing construction from a stack of nested elements (per doi:10.1038/nature13576)
- Peripatopsis capensis internal anatomy IMG 0781a.JPG
Digestive system of Peripatopsis capensis
- Dissected Euperipatoides.jpg
A dissection of the onychophoran Euperipatoides kanangrensis. The width of the dish is approx. 4 cm. The two ovaries, full of stage II embryos, are floating to the bottom of the image. The brown mass of the viscera is partially protruding from the body cavity.
Global distribution map of the Onychophora*Legend: Peripatidae (excluding the fossil Cretoperipa
- Peripatoides 226306189.gif
Peripatoides
- New Zealand peripatus, Wellington, NZ imported from iNaturalist photo 601149090.jpg
Peripatoides novaezealandiae eating a moth
- Eoperipatus totoro.jpg
Eoperipatus totoro, a basal member of Peripatidae
References
- ↑ Piper, Ross 2007. Extraordinary animals: an encyclopedia of curious and unusual animals. Greenwood Press.
- ↑ 2.0 2.1 Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).
- ↑ Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).
- ↑ Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).
- ↑ Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).
- ↑ Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).
- ↑ Thompson, Ida; Jones, Douglas S. (1980). "A possible Onychophoran from the Middle Pennsylvanian Mazon Creek beds of northern Illinois". Journal of Paleontology. 54 (3): 588–96. JSTOR 1304204.
- ↑ Lua error in Module:Citation/CS1/Identifiers at line 630: attempt to index field 'known_free_doi_registrants_t' (a nil value).