Mesotardigrada
The class Mesotardigrada has only one species, Thermozodium esakii. The animal has six claws of equal length at each foot. This species was recorded in 1937 by Rahm from a hot spring near Nagasaki in Japan. Unfortunately, the locus typicus has been destroyed by an earthquake and subsequent searches for specimens have been unsuccessful. The type specimen has also been lost, so the status of this class is considered dubious. However, Grothman et al suggests that a type specimen was never collected, in line with lax taxonomic standards of the 1930's. Grothman et al also suggests that they might have been misinterpreted heterotardigrades, possibly belonging to either Carphania or Oreella.
