''Saurophthirus'' is an extinct genus of giant

stem-group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

flea Flea, the common name for the order (biology), order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by hematophagy, ingesting the blood of their hosts. Adult f ...

, and the only member of the family Saurophthiridae. The type species, ''S. longipes'' is found in early Cretaceous strata of

Baissa The Zaza Formation is a geological formation located in Buryatia (Russia). It dates to the Lower Cretaceous. The age of the formation is disputed, and is considered likely to be Valanginian-Hauterivian, or Aptian in age. It comprises sandstones, ...

, Siberia. Two other species ''S. exquisitus'' and ''S. laevigatus'' are from the Lower Cretaceous

Yixian Formation The Yixian Formation (; formerly Romanization of Chinese, transcribed as Yihsien Formation or Yixiang Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the Barremian stage of the Early Cretaceous. I ...

of China.Gao, Taiping, et al. "New Transitional Fleas from China Highlighting Diversity of Early Cretaceous Ectoparasitic Insects." Current Biology 23.13 (2013): 1261-1266.

Description

Body length of largest species, ''S. longipes'' is long. They are generally seen as transitional between more primitive stem-fleas such as

Pseudopulicidae Pseudopulicidae is an extinct family of stem-group fleas from the Middle Jurassic to Early Cretaceous of China. They represent the oldest known group of stem-fleas. Like other stem-group "giant fleas", they are much larger and lack the specialise ...

and '' Tarwinia'' and modern fleas.

References

Siphonaptera genera Cretaceous insects Transitional fossils Cretaceous insects of Asia Parasites of reptiles Prehistoric insect genera Fossil taxa described in 1976 {{parasitic animal-stub