Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Did death-dealing cyanobacteria cause the mass deaths of Messel?

17.11.2004


In 1875 the remains of a prehistoric crocodile were found in the brown coal mine at Messel near Darmstadt; since then a large number of well preserved fossils have also been discovered. Palaeontologists have long puzzled over what could have been the reason for this annihilation of so many creatures. In the latest issue of the Paläontologische Zeitschrift (‘Journal of Palaeontology’) researchers from the University of Bonn have put forward a new theory: the cause of the deaths of these animals may have been poisoning by cyanobacteria.



The fossil site of Messel, near Darmstadt (central Germany) is a world heritage site; it is famous throughout the world for the fossils of animals and plants from a tropical landscape 47 million years ago, all of them excellently preserved. Nowhere else have so many bats and birds been found in lake deposits. Among the mammals even the contents of the stomach are usually preserved. But how did these animals die? The well-filled stomachs are not exactly an indicator of disease or fatal debility. Until recently the cause of death was assumed to be, inter alia, gases of volcanic origin which may have collected over the lake. This might explain why the animals suffocated. But such clouds of gas – if they indeed existed – must have dispersed rapidly, given the size of the lake. It is still a moot point whether, after hundreds of thousands of years, gas was still escaping from the volcanic subsoil which formed the extinct volcanic crater lake of Messel.

The University of Bonn palaeontologists on Professor Wighart von Koenigswald’s team have proposed a new theory in the latest issue of the Paläontologische Zeitschrift which sheds light on the possible cause of death. While examining the fossils the researchers became aware that the deaths must have occurred at the same time of year in different years. The five pregnant mares which were found at completely different levels in the oil shale at Messel all died at the same time of year, as the foetuses were at the same stage of development. Among the tortoises there were also five pairs which died during copulation, i.e. during the breeding season.


One more piece of the puzzle was provided when the Bonn lecturer Dr. Andreas Braun noticed that there are lime deposits in the sedimentary structures of Messel. A very similar structure occurs in lake deposits which Professor von Koenigswald’s doctoral student Thekla Pfeiffer discovered in Neumark-Nord. In deposits which were about 200,000 years old she was able to detect traces of the highly toxic microcystine, a poison which is produced by cyanobacteria. The researchers assume that the sedimentary structures in Messel are also due to these microbes, also known as ‘blue-green algae’. The animals may therefore have died from microcystine poisoning due to the seasonal algal bloom caused by deadly cyanobacteria.

From Canada we know that during algal bloom cyanobacteria cause toxic foam to collect in the surface water. Anything that drinks this water collapses almost immediately. This is true of both land animals and birds. Observations have shown that even the tiny quantities of water drunk by bats when flying low over the water can be fatal. Many aspects of the fossil finds of Messel which were not previously understood can be explained by this theory of a seasonal growth of highly toxic cyanobacteria which was repeated year after year. The theory still awaits further confirmation. One difficulty, however, is already apparent: it will be very difficult to provide direct evidence of toxic agents after 47 million years.

Prof. Wighart von Koenigswald | alfa
Further information:
http://www.uni-bonn.de

More articles from Earth Sciences:

nachricht Climate change weakens Walker circulation
20.10.2017 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen

nachricht Shallow soils promote savannas in South America
20.10.2017 | Senckenberg Forschungsinstitut und Naturmuseen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>