First robber fly described from Mexican amber (Diptera: Asilidae: Laphriinae)

Asilidae represents one of the most diverse Diptera families, the adults are rapacious predators of arthropods. Despite the huge diversity of extant species, robber flies are considered uncommon to extremely rare in amber or any type of fossil. Here we present the first Laphriinae fossil description from Miocene based on a well-preserved adult male trapped in amber from Simojovel, Chiapas, Mexico. The fossil corresponds to a new genus and species named Mioatomosites mexicanus gen. et sp. nov. This fly was likely a tree visitor, inhabiting tree trunks and vegetation, such as the Hymenaea trees that grew near mangrove swamps in Chiapas during the Miocene, which increased the chance of it being trapped in the amber. The new taxon is described and compared with other extant similar Neotropical Laphriinae genera. We postulate that Mioatomosites gen. nov. would be likely placed at the root of a given clade comprising the extant related genera, but future phylogenetic studies are necessary to better understand the relationship among Atomosiini genera. The South American continent is considered a centre of diversity for Atomosiini. This fossil record and the presence of extant Atomosiini genera in the Caribbean islands, which are currently far away from the continent, indicates that a complete land bridge would not be necessary for these "early species" to colonize what today is Central America and South of Mexico during the Miocene or even earlier.