It was a mosquito filled with dinosaur blood and surrounded by amber that helped create the made-up Jurassic Park in reality. While real bugs stuck in sticky substances haven't led to dangerous dinosaur parks (yet), they do give scientists a glimpse into their previous shapes and behaviors. A pair of termites from 38 million years ago, caught in tree resin while mating, are assisting scientists in understanding the mating behaviors of extinct insects. The discovery is discussed in a research paper released on March 5 in the Proceedings of the National Academy of Sciences (PNAS).
The two termites are an extinct species known as Electrotermes affinis (E. affinis) and the finding of this fossil was somewhat fortunate. Study co-author and entomologist from the Czech Academy of Sciences Aleš Buček saw the piece of amber on an online shop for fossil collectors.
“Termite fossils are very common, but this piece was unique because it contains a pair,” Buček stated in a release. “I have seen hundreds of fossils with termites enclosed, but never a pair,”
[Related: A 50-million-year-old insect testicle is one lucky find.]
Buček bought the fossil and a team from the Okinawa Institute of Science and Technology’s (OIST) Evolutionary Genomics Unit in Japan used an X-ray micro-CT to take a closer look at the bugs.
“Identifying the species was actually not easy, because there were bubbles in front of important parts of the termite’s bodies,” study co-author and OIST postdoctoral researcher Simon Hellemans, mentioned in a release.
The scan revealed what species they belonged to and also that the trapped termites were a female and male laying side by side. The female’s mouthparts were touching the tip of the male’s abdomen. This positioning was familiar to the researchers, as present day termites participate in a mating behavior called tandem running. The insects display coordinated movements to keep themselves together while exploring a new nest site.
However, the fossilized pair’s unusual side-by-side positioning in the amber also stood out. A pair typically would have been observed lying behind each other. The team believed that since the preservation in the amber is not an instantaneous process, the termite’s normal mating behaviors gets interrupted. Their positions then shift while they are being encased in the super sticky tree resin. To test out this hypothesis, they simulated the process in the lab.
“Our approach focused on how fossils are created and how behavior changes during the insect’s death,” study co-author and Auburn University entomologist Nobuaki Mizumoto stated in a statement.
[Related: When insects developed wings, evolution really advanced.]
They observed mating termite pairs and discovered that even if the leading individual became stuck on a sticky surface, the follower did not flee or leave their partner. Instead, they circled around them and also became stuck in a position resembling the termites trapped in amber.
“If a pair encounters a predator, they usually flee but I think on a sticky surface they do not realize the danger and become trapped,” said Mizumoto.
According to the team, this new method of simulating the process of getting trapped in tree resin allowed them to examine the behaviors of an extinct species in a more precise way. “For some things, fossils are simply the best evidence, a direct window to the past,” said Buček and Mizumoto.
