Scientists have found rare evidence of ancient parasites in action, using advanced techniques to reveal the unpleasant process by which long-extinct wasps preyed on developing insects. Dr Thomas van de Kamp and colleagues examined over 1,500 tiny fossilised fly pupae from around 23 to 66 million years ago discovered in France.

Within these cocoon-like structures that maggots form before emerging as flies, the scientists used advanced X-ray techniques to reveal adult parasitic wasps growing. In total they found 55 cases of parasitisation taking place, frozen in time inside the tiny fossils for millions of years. Based on this evidence, it seems these wasps injected a single egg inside each pupa, which they grew and consumed the developing fly for sustenance.

The scientists described four new species of wasp, and used a combination of imaging techniques to produce animated reconstructions of one of them, which they termed Xenomorphia resurrecta. The genus “Xenomorphia“ is named after the creature from the Alien science fiction film series, which is known as Xenomorph and develops in a similar way to these wasps.