Mesotardigrada Explained

Mesotardigrada is one of three classes of tardigrades,^[1] consisting of a single species, Thermozodium esakii.^{[2] [3] [4] [5] [6] [7] [8]} The animal reportedly has six claws of equal length at each foot. This species was described in 1937 by German zoologist Gilbert Rahm from a hot spring near Nagasaki, Japan. The inability of taxonomists to replicate Rahm's finding has cast doubt on the accuracy of the description, making T. esakii, and by extension the entire class Mesotardigrada, a taxon inquirendum.

Taxonomic ambiguity

The type specimen Rahm used as the basis of his description has either been lost^[9] or it was never preserved in the first place, which Grothman et al. (2017) suggest is consistent with the lax taxonomic standards of the 1930s.^[10] Thus, re-examination of the original specimen is not possible. Complicating matters further, the type locality from which Rahm collected his specimen may have been destroyed by an earthquake and subsequent searches for additional specimens matching the original description have been unsuccessful.

Grothman et al. (2017) suggest that Rahm might have observed and misinterpreted a species in the class Heterotardigrada, possibly belonging to the genus Carphania or Oreella.

See also

• Salinella – another high rank taxon whose sole member has not been independently verified to exist

External links

• • Tardigrade phylogenetics

Notes and References

1. http://www.ubio.org/browser/details.php?namebankID=596202 Namebank Record Detail
2. Web site: ION: Index to Organism Names . Organismnames.com . 10 November 2011.
3. http://data.gbif.org/species/13853106 Data Use Agreement – GBIF Portal
4. http://www.catalogueoflife.org/annual-checklist/2010/details/species/id/6845995/source/tree 2010 Annual Checklist :: Species details
5. http://www.catalogueoflife.org/annual-checklist/2010/details/reference/species/6845995 2010 Annual Checklist :: Literature references
6. Web site: micro*scope – version 6.0 – March, 2006 . Starcentral.mbl.edu . 10 November 2011 . dead . https://web.archive.org/web/20110928115532/http://starcentral.mbl.edu/microscope/portal.php?pagetitle=classification&BLOCKID=52&CHILDID=2676&namebankID=4417888 . 28 September 2011.
7. http://www.eol.org/pages/1053783 Thermozodium esakii – Encyclopedia of Life
8. http://www.ubio.org/browser/details.php?conceptID=&namebankID=596205&classID=110&lineage=230572|230453|596202|9746382|596203|596204 Namebank Record Detail
9. Nelson, Diane R. . 2002 . Current Status of the Tardigrada: Evolution and Ecology . Integrative and Comparative Biology . 42 . 3 . 652–659 . 10.1093/icb/42.3.652. 21708761 . free .
10. Grothman. Gary T.. Johansson. Carl. Chilton. Glen. Kagoshima. Hiroshi. Tsujimoto. Megumu. Suzuki. Atsushi C.. February 2017. Gilbert Rahm and the Status of Mesotardigrada Rahm, 1937. Zoological Science. 34. 1. 5–10. 10.2108/zs160109. 28148217. 0289-0003. free.