Mesotardigrada is one of three
classes of
tardigrades
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 ...
, consisting of a single species, ''Thermozodium esakii''. 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
is a Prefectures of Japan, prefecture of Japan located on the island of Kyūshū. Nagasaki Prefecture has a population of 1,314,078 (1 June 2020) and has a geographic area of 4,130 Square kilometre, km2 (1,594 sq mi). Nagasaki Prefecture borders ...
. 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
In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...
Rahm used as the basis of his description has either been lost
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.
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
The class Heterotardigrada includes tardigrades (water bears) that have cephalic appendages and legs with four separate but similar digits or claws on each. 444 species have been described.
Anatomy
The anatomy of the reproductive system is an ...
, 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
References
External links
*
Tardigrade phylogenetics*
{{Taxonbar, from1=Q2008466, from2=Q601814, from3=Q2007755, from4=Q2007760, from5=Q2008481
Tardigrades
Protostome classes
Monotypic animal taxa