Tracheal system and biology of the Early Cretaceous Saurophthirus longipes Ponomarenko, 1976 (Insecta, ?Aphaniptera, Saurophthiroidea stat. nov.)

Abstract

The tracheal system of Saurophthiridae is described based on female fossils of Saurophthirus longipes Ponomarenko, 1976. Three very wide tracheal trunks are found running dorsolaterally along each side of the body. The tracheal system is amphipneustic, with the large mesothoracic and very large 8th abdominal spiracles. The 9th and following segments are able to turn back to open posterior spiracles for breathing. Taken together, these features are characteristic of air breathing aquatic insects. This urges us to modify the former hypothesis about parasitism of Saurophthirus on pterosaur wing membrane. We suppose that Saurophthirus females had gonotrophic cycles: they imbibed blood enough for maturation of a large egg batch, then retreated to a water body as a safe place for digesting and egg maturation, and after oviposition climbed onto emergent plants and waited for pterosaurs patrolling over the water and looking for fish, to start a new cycle. The families Saurophthiridae, Pseudopulicidae, and Tarwiniidae are united in the superfamily Saurophthiroidea Ponomarenko, 1986, stat. nov.