Introduction

Fossil records can provide insights into anatomical diversification, historical biogeography and the antiquity of taxa, but they are too incomplete to document precisely the divergence and ages of taxonomic groups. In the case of mosquitoes, the fossil record is so poor that it is not possible to establish the actual ages of the family and extant taxa. Edwards (1923) surmised that ‘The origin and phylogenetic history of the Culicidae must go back to well into the Mesozoic Era; and, from the small size and fragile nature of the insects, it is probably too much to hope that we can ever obtain much direct palaeontological evidence on these matters'

A number of fossil species have been assigned to Culicidae since the beginning of binomial nomenclature, but only 26 can be placed in the family with confidence (see Fossil taxa; nominal species removed from Culicidae are listed below). Twenty-two of the fossil mosquito species are from the Cretaceous Era, including species of Anopheles, Culex, Mansonia, Toxorhynchites and six extinct genera. The discovery of the two cretaceous species confirms Edwards' (1923) view that the evolution of Culicidae must extend into the Mesozoic. The oldest fossils, Burmaculex antiquus Borkent & Grimaldi (Burmaculicinae) and Priscoculex burmanicus Poinar, Zavortink & Brown (Anophelinae) are embedded in Myanmar (Burmese) amber from the mid-Cretaceous (89.3-99.6 Mya)*. Burmaculex antiquus bears several plesiomorphic features, including a short proboscis, which suggest it is a stem-group mosquito that is intermediate between extant mosquitoes and other midges. In fact, the phylogenetic analysis of morphological data conducted by Borkent & Grimaldi (2004) indicates that Burmaculex is the sister group of all other fossil and modern mosquitoes. Priscoculex burmanicus, in addition to bearing a predominance of anopheline characters, bears some unique features, including a setose proboscis, setose maxillary palpi and long setae on the wing veins that are considered to be ancestral characters. The next oldest fossil, Paleoculicis minutus Poinar et al., is entombed in Canadian amber from the Upper Cretaceous (100.5–66.0 Mya). Morphological features indicate that Paleoculicis shares a closer affinity with culicine than anopheline mosquitoes, which suggests that this ancestral lineage is younger than the lineage that gave rise to subfamily Anophelinae. Besides Priscoculex burmanicus, Anopheles (Nyssorhynchus?) dominicanus Zavortink & Poinar and Anopheles? rottensis Statz are the only fossil anopheline mosquitoes. The former is contained in Dominican amber from the Eocene (33.9-40.4 Mya) and the latter is from the Oligocene of Germany (23.0-28.4 Mya). From the available fossil evidence, it appears that extant groups of Culicidae may have evolved in the Cenozoic.

Nominal species removed from Culicidae

Amblylexis gibberata Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Amianta eurycephala Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Amphipromeca acuta Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Apistogrypotes inflexa Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Asioculicus damiaoensis Hong, 1976 (not Culicidae – Poinar et al., 2000), Jurassic-Cretaceous, China.
Asioculicus longipodus Hong & Wang, 1976 (not Culicidae – Poinar et al., 2000), Jurassic-Cretaceous, China.
Chironomaptera gregaria Kalugina, 1980 (Chaoboridae – Evenhuis, 1994), Cretaceous, China.
Cormophora arucaeformis Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Culex fossilis Brodie, 1845 (Chironomidae – Edwards, 1923), Jurassic, England.
Culex proavitus Scudder, 1877 (Psychodidae – Edwards, 1923), Eocene, Fossil Canyon, Utah, USA.
Culiciscolex gibberatus Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Culicites tertiarius von Heyden, 1862 (Chaoboridae – Edwards, 1923), Late Oligocene, Germany.
Cyrtomides maculatus Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Ellipes laesa Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Empidocampe retrocrassata Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Propexis incerta Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Rhopaloscolex brevis Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Rhopaloscolex longus Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.
Sphallonymphites decuratus Bode, 1953 (not assignable to family – Carpenter, 1992), Jurassic, Germany.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith