The Author first recalls the past of eutardigrade taxonomy and indicates the main factors that for a long time restrained its progress. One consequence of a superficial analysis is that very wide individual variability has been erroneously attributed to many species, and this has become the main problem for tardigrade taxonomists. The situation began to change after 1969 because of the first attempts to eliminate the above mentioned problems. Novelties gave impetus to the revision of tardigrade taxonomy, and genuine systematics, finally based on phylogenetics, became popular. Today the morphological characters are considered more in depth and studies utilising DNA sequences are more in fashion; they are surely useful and allow the distinction of morphologically very similar species. However, in the author’s opinion, this progress will be possible only if the molecular studies are always associated with careful morphological studies, which, in the meantime, will be more and more detailed also thanks to the use of the Scanning Electron Microscopy (SEM).
Tardigrade, taxonomy, evolution.