Fossil evidence of social insect commensalism in the Phoridae (Insecta: Diptera)

Fossil phorid flies display various levels of morphological change that are correlated with myrmecophily (association with ants) and termitophily (association with termites) in the modern fauna. Three discrete episodes in the evolution of limuloidy, a defensive body form, are documented from Eocene Baltic amber. Extinct fossil stem-group taxa of the modern myrmecophilous genus Aenigmatias Meinert are described, with three new species – A. longicornis sp. nov., A. primitivus sp. nov. and A. nigeroticus sp. nov. – recognized and illustrated. Protoplatyphora Brues is synonymized with Aenigmatias, with its single previously described species, A. tertiarius (Brues), considered a new combination. Chaetopleurophora bisetosa Brown, 2007 is transferred to Aenigmatias as A. bisetosus (comb. nov.). An unrelated Aenigmatias-like fossil is described as Pseudaenigmatias ctenitibia gen. et sp. nov., and belongs to a modern termitophilous clade. Limulomyia tyche Brown, 1999 is interpreted as a separate, already highly limuloid lineage not related to either of the other two limuloid groups. A key to fossil Aenigmatias is given, along with a phylogenetic analysis of fossil taxa. Fossil specimens have profound implications for our knowledge of the evolution of the limuloid body form found in modern species of Aenigmatias.
http://zoobank.org/urn:lsid:zoobank.org:pub:DE779D49-7636-4B1D-9F7D-CF3FF6D3CE97