28-VIII PROTOSTOMIA Panarthropoda	Select Chapter/Biodiversity TreeHomeBiodiversity Tree1. Physics2. Chemistry3. Astronomy4. Geology5. Cell Structure6. Molecular Biology7. Photosynthesis and Respiration8. Molecular Genetics9. Mitosis and Meiosis10. Mendelian Genetics11. Populations12. Communities13. Ecosystems14. Evidence of Evolution15. Theory and Process of Evolution16. Classification Systems17. Prokaryotes18. Eukaryota19. Viridiplantae (Plants)20. Embryophyta21. Tracheophyta22. Spermatophyta23. Magnoliophyta24. Fungi25. Metazoa (Animals)26. Eumetazoa27. Bilateria28. Coelomata29. Arthropoda30. Insecta31. Deuterostomia32. Chordata33. Vertebrata34. Teleostomi35. Tetrapoda36. Sauroposida37. Aves38. Mammals39. Western/Coniferous Forests40. Taiga (Northern Forests)41. Eastern/Deciduous Forests42. Tropical Forests43. Deserts44. Polar Environments45. Tundra46. Grasslands47. Wetlands48. Freshwater Environments49. Estuaries50. Marine Environments51. Extreme Environments
	Velvet Worm [© Adam G. Clause] Chapter Outline Description of Protostomia Classification of Protostomia Lophotrochozoa Annelida Mollusca Gnathifera Ecdysozoa Panarthropoda Sources Links to external sites will appear in pop-up windows.			Panartropoda is a group containing the arthropods, as well as two similar phyla. Tardigrada and Onychophora will be explored on this page. Arthopoda gets its own chapter (next). Protostomia Spiralia Lophotrochozoa (28-III) Mesozoa Dicyemida - Rhombozoans Orthonectida - Orthonectids Platyhelminthes - Flatworms Nemertea - Ribbon Worms Annelida - Segmented Worms (28-IV) Phoronida - Horseshoe Worms Brachiopoda - Lampshells Mollusca - Molluscs (28-V) Bryozoa - Bryozoans Entoprocta - Entoprocts Cycliophora - Symbion pandora Gastrotricha - Gastrotrichs Acanthocephala - Thorny-Headed Worms Gnathifera (28-VI) Rotifera - Rotifers Gnathostomulida Micrognathozoa Chaetognatha - Arrow Worms Ecdysozoa (28-VII) Nematoda - Roundworms Nematomorpha - Horsehair Worms Scalidophora Kinorhyncha - Spiny-Headed Worms Loricifera - Loriciferans Priapulida - Priapulid Worms Panarthropoda (28-VIII) Tardigrada - Tardigrades (Water Bears) Onychophora - Velvet Worms Arthropoda (Ch. 29) >>> (Arthropods) TARDIGRADA   The phylum of "water bears" is split into two classes. As of 2024, 4 species of Tardigrada have been observed in iNaturalist in the US and 29 throughout the world. CLASS EUTARDIGRADA ORDER APOCHELA Tardigrade (Milnesium tardigradum) ORDER PARACHELA Tardigrade (Macrobiotus) Tardigrade (Paramacrobiotus tonollii) CLASS HETEROTARDIGRADA ORDER ARTHROTARDIGRADA ORDER ECHINISCOIDEA Tardigrade (Viridiscus viridissimus) Resources: Tardigrade Links ONYCHOPHORA   This is the phylum of Velvet Worms. As of 2024, there have been no species of Onychophora observed in iNaturalist in the US but 80 throughout the world. Most are observed in Eastern Australia, New Zealand, South Africa and Central to South America. New Zealand Peripatus (Peripatoides novaezealandiae) - most iNat observations in the world for Onychophora Resources: Introduction to the Onychophora - UCMP Velvet Worms (Peripatus) Velvet Worms [ Previous Page ] [ Next Page ]