Dorsal chaetotaxy of neotropical species supports a basal position for the genus Lepidonella among scaled Paronellidae (Collembola, Entomobryoidea)

Lepidonella is a small genus of scaled Paronellidae comprising 12 species distributed mainly across the Ethiopian, Oriental and Australian biogeographic regions. Most species are poorly described by current standards and little is known about their dorsal chaetotaxy. Previous observations of the chaetotaxy of the second and third abdominal segments led to suggestions that Lepidonella may be more closely related to Lepidocyrtus than to other paronellids, thus rendering Paronellidae polyphyletic. Here we describe the complete dorsal chaetotaxy of the Neotropical species, Lepidonella incerta (Mari Mutt, nec Handschin), and Lepidonella zeppelinii sp. nov., to evaluate the position of Lepidonella among genera of scaled Paronellidae. The abundant, largely undifferentiated chaetotaxy of L. incerta and L. zeppelinii sp. nov. suggests a basal position for Lepidonella among scaled Paronellidae. Putative synapomorphies of the chaetotaxy of the head and metathorax supporting the monophyly of Lepidonella lead us to conclude that most similarities in chaetotaxy between New World Lepidonella and Lepidocyrtus represent symplesiomorphies. We also conclude that Paronellidae s. lat. (i.e., including Cyphoderinae) is derived from an Orchesellinae or Heteromurini-like species and is sister to Entomobryinae. In addition, we describe L. zeppelinii sp. nov. from Brazil, the first member of the genus described for South America, we propose a new name, L. marimuti n. name, for L. incerta (Mari Mutt), which is a junior homonym of L. incerta (Handschin), transfer to the genus Trogolaphysa two species previously assigned to Lepidonella, and provide an identification key to the species of Lepidonella of the world.