According to the latest research results of a German-Mexican team of geoscientists, the gradual decline of the dinosaurs and pterosaurs presumably came before the impact of the Chicxulub asteroid and the global mass extinction at the end of the Cretaceous Period. Studies under the direction of Prof. Dr Wolfgang Stinnesbeck of Heidelberg University and Prof. Dr Eberhard Frey of the State Museum of Natural History Karlsruhe also indicate that bird species spread and diversified at the same time the dinosaurs disappeared. Their results were published in the journal “Geological Society of America Bulletin.”
While conducting paleontological research in northeastern Mexico, the scientists came upon sedimentary rock deposited toward the end of the Cretaceous Period that evidenced an enormous diversity of fossils, including the tracks of birds, dinosaurs and pterosaurs.
Prints of azhdharchidea Pterosaurs in a sandstone of the Cretaceous Period. Location: Rancho San Francisco near Paredon, northeastern Mexico.
Photo: Wolfgang Stinnesbeck
"Most of the imprints come from at least five different species of birds; dinosaur tracks, however, are rare. Only a single footprint comes from a predatory dinosaur," explains Prof. Stinnesbeck. The finds therefore indicate a gradual decline of the dinosaurs with a simultaneous increase in the diversity of birds even before the end of the Cretaceous Period.
"Until now, it was generally assumed that the dinosaurs died out first and bird species diversified afterward," states the researcher. "Our data, however, substantiate the theory that birds ascended before dinosaurs became extinct."
Fossil analysis also showed that the decline of the dinosaurs occurred gradually, with probably only a few species surviving until the end of the Cretaceous Period. The extinction of the dinosaurs is therefore not – as science frequently assumes – due to the impact of the Chicxulub asteroid that struck the earth more than 65 million years ago.
"For most of the dinosaurs and pterosaurs, this strike no longer had any effect," explains Prof. Stinnesbeck. Even the group of cephalopods, the so-called ammonites, was not annihilated by the asteroid strike at the end of the Cretaceous Period. According to Prof. Stinnesbeck, fossil finds of the Sphenodiscus pleurisepta ammonite show their successive decline beyond the Cretaceous Period.
"The effects of the Chicxulub impact were therefore not the cause of a global mass extinction, which probably came about considerably less catastrophically than previously assumed," states the Heidelberg researcher.
W. Stinnesbeck et al.: Theropod, avian, pterosaur, and arthropod tracks from the uppermost Cretaceous Las Encinas Formation, Coahuila, northeastern Mexico, and their significance for the end-Cretaceous mass extinction. Geological Society of America Bulletin (Vol. 129, No. 3-4), doi: 10.1130/B31554.1
Prof. Dr. Wolfgang Stinnesbeck
Institute of Earth Sciences
Phone +49 6221 54-6057
Communications and Marketing
Phone +49 6221 54-2311
Marietta Fuhrmann-Koch | idw - Informationsdienst Wissenschaft
Exploring ocean waters to characterize atmospheric aerosols
31.03.2017 | Université de Genève
As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation
29.03.2017 | University of Hawaii at Manoa
Plant pollen and fungal spores can be found at variable heights in the air, even at elevations up to 2000 meters. This is the conclusion of a report by researchers of Helmholtz Zentrum München and Technical University of Munich together with Greek colleagues, which was published in the journal ‘Scientific Reports’. Hitherto it was assumed that such allergens are mainly present close to where they are released, namely near ground level.
One in every five Europeans currently already suffers from allergies – and the trend is increasing. Plant pollen and fungal spores contribute considerably to...
By comparison, a blink lasts a lifetime – atoms can rearrange themselves within one 350 quadrillionths of a second. As reported in the latest issue of the prestigious journal Nature, scientists at the Center for Nanointegration (CENIDE) at the University of Duisburg-Essen (UDE), together with their colleagues from the University of Paderborn, have been able to observe the movement of a one-dimensional material in real-time. Their research confirms that the acceleration of the atoms could leave even a Porsche standing.
Everything that surrounds us in our everyday life is three-dimensional, no matter how small: salt crystals, pollen, dust – even aluminium foil has a certain...
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
03.04.2017 | Event News
20.03.2017 | Event News
14.03.2017 | Event News
03.04.2017 | Event News
03.04.2017 | Health and Medicine
03.04.2017 | Physics and Astronomy