New multilocus phylogeny reorganises the family Macrobiotidae (Eutardigrada) and unveils complex morphological evolution of the Macrobiotus hufelandi group

• Phylogenetic analysis recovered monophyly of the tardigrade genus Macrobiotus. New evolutonaly distinct group is erected to level ( Sisubiotus gen. nov.) The Xerobiotus deeply nested within Macrobiotus and thus suppressed. Distinct species complexes are delineated. Demonstration complex phenotypic evolution family Macrobiotidae. Macrobiotidae one most speciose diverse groups among tardigrades. Although there have been attempts reconstruct phylogeny this family, evolutionary relationships only superficially determined as available genetic data cover a small fraction vast group. Here, we present first extensive molecular based on four markers (18S rRNA, 28Sr RNA, ITS-2 COI) associated with detailed morphological for majority taxa. phylogenetic includes nearly two hundred sequences representing more than sixty species, including sixteen taxa that never sequenced and/or analysed phylogenetically before. Our results new monophyletic group, comprising spectabilis Thulin, 1928 grandis Richters, 1911, which erect genus, nov. , accommodate its distinctiveness. largest, so far, dataset showed clade deeper it was earlier assumed, therefore propose suppress transfer . Moreover, mapping key traits onto macrobiotid exposed phenotypes hufelandi i.e. s.s Finally, our findings enabled revision discussion compositions ubiquitous genera, complexes, resulted in changes taxonomic statuses number species. All contributes reconstruction