LAUSR

ABSTRACT In this paper we redescribe and illustrate the holotype of Paranoika placida Zamboni, Martins-Neto & Popov, 2002 from the Lower Cretaceous of Brazil (Crato Formation). We propose that the family Paranoikidae Zamboni et al., 2002 (type genus: Paranoika Zamboni et al., 2002) is a junior synonym of Belostomatidae Leach, 1815. Paranoika (type species: P. placida) is a junior synonym of Lethocerus Mayr, 1853. Thus Paranoika placida Zamboni, Martins-Neto & Popov, 2002 becomes Lethocerus placidus (Zamboni, Martins-Neto & Popov, 2002) comb. nov. We also propose that L. placidus comb. nov. is the senior synonym of Lethocerus vetus Nel & Waller, 2006, syn. nov. Multivariate statistical analyses including L. placidus comb. nov. and extant Lethocerus species were carried out with the aim of preliminarily discussing possible relationships between morphological similarities and patterns of geographical distribution of the genus.