Piecing together Baltic amber fungus gnats: a comprehensive review and material assessment

Abstract

• Fungus gnats (Diptera, Sciaroidea) represent the largest group in the fossil record and are among the most diverse groups of living flies. The Mycetophilidae family alone comprises approximately 400 described fossil species (surpassed only by Limoniidae) in 126 genera. The majority of these species were described from Baltic amber by Hermann Loew (in 1850 pamphlet) and Fernand Anatole Meunier (in a series of publications in 1899-1923). However, the study of Cenozoic fungus gnats has been significantly hindered by inadequate descriptions and, in many cases, the absence of type material. In this work, we review all species of fungus gnats (Diptera, Sciaroidea, excluding Sciaridae and Cecidomyiidae) known from Baltic amber and locate remaining type material. Fungus gnats in Baltic amber are represented by 258 species names, of which 44 are nomina nuda and 88 are nomina dubia. Our revision results in 53 new combinations, 6 new species synonyms, and 2 potential generic synonyms. Lectotypes are designated for 33 species, and neotypes for 8 species. Additionally, 23 species will be described as new. Unfortunately, for 88 species classified as nomina dubia, the type material has been lost, and the descriptions are inadequate for neotype selection. The type material of Loew and Meunier is located in the Institut und Museum für Geologie und Paläontologie, GeorgAugust-Universität, Göttingen (Königsberg collection), the Paläontologisches Museum, Humboldt-Universität, Berlin (Loew material from Berendt's collection), the Natural History Museum, London (part of Berendt's collection studies by Loew), and the National Zoological Museum of Franko Lviv National University