Evrim Yazgin
Cosmos science journalist
In an event mirroring Hollywood, palaeontologists have uncovered a kind of parasitic wasp preserved in amber which lived almost 100 million years ago.
Its unique parasitic behaviour is more similar to a plant than an insect.
Viewers of Steven Spielberg’s classic Jurassic Park (1993) may recall the opening scene where miners uncover a mosquito trapped in amber. The dinosaur blood within the mosquito is the key to bringing dinosaurs back to life – with disastrous consequences.
Insects fossilised in amber from the age of dinosaurs aren’t just a fiction. In fact, thousands have been discovered since the late 1800s. Baltic amber alone has resulted in the discovery of more than 3,000 extinct species – mostly insects. Dominican amber has preserved more than 1,000.
The newly discovered extinct species has been named Sirenobethylus charybdis – named for the sea monster, Charybdis, in Greek mythology which drank and regurgitated water 3 times a day. S. charybdis is described in a paper published in the Springer journal BMC Biology.
It was discovered in Kachin amber (also known as Burmese amber) dug up in northern Myanmar’s Kachin state. Scientists announced the skull of a small reptile in Kachin amber in 2020. The creature, named Oculudentavis khaungraae, also dates to 99 million years ago (mya) and was originally thought to be the smallest dinosaur ever found – that claim has since been retracted. It is more likely a small lizard than a hummingbird-sized dinosaur.
S. charybdis dates from 98.79 mya, and is known from 16 adult female wasps preserved in amber. The insect lived during the middle of the Cretaceous period (145 to 66 mya) when the region would have been a humid, tropical or subtropical rainforest.
Micro-CT scans of the specimens reveal that the species was likely a koinobiont – a type of parasitic organism which allows its host to continue growing while feeding on it.
The wasps have an abdominal feature with 3 flaps. The lower flap forms a paddle-shaped structure with a dozen hair-like bristles, similar to a Venus flytrap plant. This abdominal apparatus has never been seen in any known insect.
S. charybdis may have used its Venus flytrap-like flaps to temporarily restrain its host while laying its eggs.
The wasp was probably unable to chase prey over long distances. Instead, it probably waited with its flaps open for a potential host to activate the flaps’ capture response. Again, this is reminiscent of the way a Venus flytrap hunts.
Its main targets were probably mobile prey like small winged or jumping insects.
The authors write that the species suggests a new family of parasitic wasp closely related to other Chrysidoidea – the superfamily which includes modern parasitic wasps like the cuckoo wasp.
