Whether flies, dragonflies or bees – trapped in resin, many insects have survived the eons. Paleontologists make such finds fascinating insights into the world of creatures that lived on Earth millions of years ago.
Now, researchers in Baltic amber have first discovered a specimen of a large butterfly caterpillar – a previously unknown species. The 44-million-year-old fossil is a larva from the group of Spanner Butterfly (Geometridae), as reported by the Zoologische Staatssammlung München. The research team describes the preserved insect in the scientific journal "Scientific Reports".
Baltic amber is widespread in the Baltic Sea region. The butterfly larva was once encased in a drop of resin that solidified into amber over time, keeping the animal forever. "It's the first time ever that we came across such a large butterfly fossil in Baltic amber," says co-author Axel Hausmann. The fact that only such extremely rare caterpillars were included in amber is probably due to the fact that these animals were predominantly nocturnal. Hausmann: "And the resin, in turn, was usually only liquid at higher temperatures and direct sunlight."
With the conserved larva, the Munich paleontologists have discovered a new species, which was assigned under the name "Eogeometer vadens" the so-called barking tensions. Spinner butterflies are among the three largest butterfly families, with more than 23,000 known species. In contrast to most other butterflies, their caterpillars only have a single pair of abdominal feet in addition to the breast and abdomen. This allows them a typical form of locomotion, where they push their hind legs directly to the abdominal legs. As a result, the body forms a sort of loop when the caterpillar wanders.
Thilo Fischer, an expert on fossil butterflies and plants and first author of the study, hopes for further spectacular finds from Baltic amber. Each butterfly fossil gives an exciting insight into the evolutionary processes of the Eocene, a hitherto little explored epoch of the Earth's history about 34 to 56 million years ago. At that time, the spread of flowering plants, as we know them today, had already been largely completed, Fischer said.
Unusual amber finds make researchers again and again. Most recently, they discovered a 100 million year old flower in the tree resin. a dragonflies mating ritual and the tail of a dinosaur.