Hide-and-Seek with Tiny Neotenic Beetles in One of the Hottest Biodiversity Hotspots: Towards an Understanding of the Real Diversity of Jurasaidae (Coleoptera: Elateroidea) in the Brazilian Atlantic Forest.

Simple Summary: Jurasaidae are small neotenic beetles which were only recently discovered in the Brazilian Atlantic Forest biodiversity hotspot. They have a limited dispersal propensity due to their larviform wingless females. Only adult males are capable of flight. So far, only three species classified in two genera are known. Here, we report the discovery of two new species together with a morphologically and geographically interesting population of one already described species. Our discovery is important not only for understanding the diversity of the group but also from a biogeographic point of view. For the first time, we report here the discovery of a jurasaid species from the relatively dry transitional zone between the Atlantic Forest and the Caatinga biomes. Considering our recent findings as well as the minute body size and cryptic lifestyle of Jurasaidae, we expect many more species will be discovered in the future from the Atlantic Forest and possibly also other surrounding ecoregions. Our study should motivate colleagues not only to perform field research in the eastern part of South America but also to pay special attention to yet undetermined materials deposited in local institutions, laboratories and collections. Jurasaidae are a family of neotenic elateroid beetles which was described recently from the Brazilian Atlantic Forest biodiversity hotspot based on three species in two genera. All life stages live in the soil, including the larviform females, and only adult males are able to fly. Here, we report the discovery of two new species, Jurasai miraculum sp. nov. and J. vanini sp. nov., and a new, morphologically remarkable population of J. digitusdei Rosa et al., 2020. Our discovery sheds further light on the diversity and biogeography of the group. Most species of Jurasaidae are known from the rainforest remnants of the Atlantic Forest, but here for the first time we report a jurasaid species from the relatively drier Atlantic Forest/Caatinga transitional zone. Considering our recent findings, minute body size and cryptic lifestyle of all jurasaids, together with potentially high numbers of yet undescribed species of this family from the Atlantic Forest and possibly also other surrounding ecoregions, we call for both field research in potentially suitable localities as well as for a detailed investigation of a massive amount of already collected but still unprocessed materials deposited in a number of Brazilian institutes, laboratories and collections. [ABSTRACT FROM AUTHOR]