Water-color by Ahlberg (representing Elginerpeton from Scotland) showing roughly what a Devonian tetrapod might have looked like.
In the 19th century a fossil was uncovered in Belgium that was believed to be the jaw of a fish. Now a team of scientists have shown that it is in fact a fossil from an ancestor of all present-day land animals. It is the first discovery of a so-called tetrapod from the Devonian Period in continental Europe, which may trigger an interest in re-examining objects in museums.
In collaboration with researchers from France, England, and Belgium, Per Ahlberg, professor of evolutionary organism biology at Uppsala University, has demonstrated for the first time that four-legged fish, tetrapods, existed on the European continent during the Devonian Period (about 365 million years ago). These first land vertebrae became the ancestors of all present-day vertebrate amphibians, reptiles, birds, and mammals--and humans. The find also resembles the known “four-legged fish” Ichthyostega that was found by Swedish scientists in Greenland in the 1930s. Fossils of tetrapods from the Devonian Period are extremely rare. In recent years fragments have been found in the US, Scotland, Latvia, and China, among other places, but none of these bear any striking resemblance to Ichthyostega.
The fossil from Belgium is fragmentary (a portion of a lower jaw) but is interesting for several reasons:
Today we have considerably more detailed anatomical knowledge about the earliest tetrapods than 20 or 100 years ago, which makes it possible to identify them even from tiny fragments, such as portions of a lower jaw. In the past it would have been necessary to have at least the better part of a skull (or the rest of the skeleton) in order to recognize a tetrapod. Methods for extracting the fossil from its enclosing stone have also advanced substantially. A new and extremely interesting technique is CT scanning, entailing a series of "x-ray sections" through a fossil, thus visualizing its three-dimensional structure even while it is fully embedded in stone.
Anneli Waara | alfa
Artificial Glaciers in Response to Climate Change?
10.08.2018 | Universität Heidelberg
Planet at risk of heading towards irreversible “Hothouse Earth” state
07.08.2018 | Potsdam-Institut für Klimafolgenforschung
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.
Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...
If certain signaling cascades are misregulated, diseases like cancer, obesity and diabetes may occur. A mechanism recently discovered by scientists at the Leibniz- Forschungsinstitut für Molekulare Pharmakologie (FMP) in Berlin and at the University of Geneva has a crucial influence on such signaling cascades and may be an important key for the future development of therapies against these diseases. The results of the study have just been published in the prestigious scientific journal 'Molecular Cell'.
Cell growth and cell differentiation as well as the release and efficacy of hormones such as insulin depend on the presence of lipids. Lipids are small...
You seem to be standing in the plasma vessel looking around: Where otherwise plasmas with temperatures of several million degrees are being investigated, with...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
10.08.2018 | Physics and Astronomy
10.08.2018 | Life Sciences
10.08.2018 | Life Sciences