Amber fossils: a journey to prehistoric times

27 August 2019

Photo: UHH/CeNak, Siemers

X-ray microtomography provides scientists with new images and information about arachnids and insects that became trapped in amber millions of years ago.

They are time capsules from prehistoric times: tiny animals preserved in amber can give us insights into an era when Central Europe had a subtropical to tropical climate. Hermetically encapsulated in amber millions and millions of years ago, the physical details and positions of the organisms remain intact to the present day. Scientists from CeNak and other institutions are now trying to gather more precise information about the fossilized arachnids and insects using x-ray microtomography at the DESY research center. They hope that the imaging technique will yield insight into the climate and life of early ecosystems and the taxonomic relationships between the various species.

The forests of the Paleogene, where the amber was produced 40–50 million years ago, existed in completely different climate conditions from those we have today. The paleontologist Ulrich Kotthoff described the purpose of the project as follows: “The high-resolution, 3-dimensional scans allow us to identify the enclosed animals more accurately and understand the environmental and climate conditions of past ecosystems better. We can draw conclusions about our own, contemporary climate changes and their impact on habitats and biocenoses.”

Unique amber arachnids

The detailed representations also enable the researchers to understand the evolution of arachnids and the development of their biodiversity. “For comparison, we are also looking at even older amber fossils from around 90 million years ago.” Ulrich Kotthoff is the head of the Geological-Paleontological Museum at CeNak. The museum houses a unique collection that includes arachnids encapsulated in Baltic and Bitterfeld amber. Some of its exhibits are now being scanned at DESY in partnership with the Helmholtz-Zentrum Geesthacht, Center for Materials and Coastal Research (HZG).

Arachnologists and entomologists from CeNak contribute to the research projects alongside scientists from other institutes, such as the Zoological Research Museum Alexander König in Bonn, and the Senckenberg Research Institute and Natural History Museum in Frankfurt.

Suspected subtropical conditions in Central Europe

Within the scope of another project, the researchers plan to scan larvae and mature insects, such as mantises, orthoptera (grasshoppers and crickets) and heteroptera (true bugs), at DESY. It is difficult to identify larvae fossilized in amber using conventional methods alone. Kotthoff hopes that the 180-degree scans will enable his team to recognize morphological characteristics in greater detail and understand in what ways the fossilized insects are related to insects living among us today.

“We have already been able to identify a previously unidentified arachnid family, which is now extinct in Europe, in Bitterfeld Bernstein.” A region near the town of Bitterfeld is one of the most important sources of amber and highly relevant to the CeNak researchers’ interests. “Much like the mantises we have examined, this discovery indicates that Central Europe used to have a considerably warmer, possibly subtropical climate. If we can identify the small arachnids and insects more accurately, we will be able to draw better conclusions about those climate conditions and, in turn, about the biodiversity of the amber forests.”

Contact

Dr. Ulrich Kotthoff
Head of the Geological-Paleontological Museum
Center of Natural History
Universität Hamburg
Bundesstraße 55
20146 Hamburg

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