Back to prehistoric times with amber insects

27 August 2019

Photo: UHH/CeNak, Siemers

Via X-ray microtomography, science is getting entirely new images and information about spiders and insects that were encased in amber millions of years ago.

They are time capsules from prehistoric times: tiny animals encased in amber provide information from a time when subtropical to tropical climates prevailed in Central Europe. Enclosed airtight in liquid resin millions of years ago, the movements and physical details of the creatures have been preserved. Using X-ray microtomography at the German Electron Synchrotron DESY, scientists from CeNak and others now want to obtain more precise information about arachnids and insects enclosed in amber. They should provide conclusions about the climate and life of earlier ecosystems as well as about the relationships of the species.

The Paleogene forests of 40-50 million years ago, from which the resin originates, existed under completely different climatic conditions. "Using the high-resolution, three-dimensional scans, we can identify the animals encased in amber more precisely and better understand their demands on the environment and climate of earlier ecosystems," says paleontologist Ulrich Kotthoff, describing one goal of the project. "In this way, we can also draw conclusions about climatic changes of our time and their influence on habitats and communities."

Unique amber arachnids

Furthermore, the detailed imaging helps to trace the evolution and diversity development of the arachnids. "We also look at even older ambers, about 90 million years old, to match species." Ulrich Kotthoff heads the Geological-Paleontological Museum at CeNak. A unique collection of, among other things, arachnids in Baltic and Bitterfeld amber is archived here, some of which are now being scanned at DESY in cooperation with the Helmholtz-Zentrum Geesthacht (HZG).

Colleagues from the arachnology and entomology departments of CeNak are involved in the research projects. In addition, scientists from other institutes such as the Alexander König Zoological Research Museum in Bonn and the Senckenberg Research Institute and Natural History Museum in Frankfurt are participating.

Presumably subtropical conditions in Central Europe

In another project, the scientists plan to scan both larvae and adult insects such as praying mantises, grasshoppers and bugs at DESY. Larvae encased in amber, in particular, are difficult to determine using conventional methods. In contrast, Kotthoff hopes the 180-degree scans will offer the opportunity to better identify morphological features and clarify relationships of fossil insects and those living today.

"We have already succeeded in detecting a previously unrecorded arachnid family in Bitterfeld amber that no longer occurs in Europe today," Kotthoff recounts enthusiastically. Near Bitterfeld lies one of the important amber deposits that particularly interests the researchers at CeNak. "The find, like the praying mantises we studied, indicates that we had much warmer, probably subtropical conditions here in Central Europe. If we can determine the small arachnids and insects in particular more precisely, we can estimate the climatic conditions even more accurately and also record the biodiversity of the amber forests much better."

Contact

Dr. Ulrich Kotthoff
Leitung Museum of Nature -Geology
LIB
Bundesstraße 55
20146 Hamburg

Tel.: +49 40 42838-5009
E-Mail: Ulrich.Kotthoff@uni-hamburg.de(ulrich.kotthoff"AT"uni-hamburg.de)