Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Closing the gap between fish and land animals

26.06.2008
New exquisitely preserved fossils from Latvia cast light on a key event in our own evolutionary history, when our ancestors left the water and ventured onto land. Swedish researchers Per Ahlberg and Henning Blom from Uppsala University have reconstructed parts of the animal and explain the transformation in the new issue of Nature.

It has long been known that the first backboned land animals or "tetrapods" - the ancestors of amphibians, reptiles, birds and mammals, including ourselves - evolved from a group of fishes about 370 million years ago during the Devonian period. However, even though scientists had discovered fossils of tetrapod-like fishes and fish-like tetrapods from this period, these were still rather different from each other and did not give a complete picture of the intermediate steps in the transition.

In 2006 the situation changed dramatically with the discovery of an almost perfectly intermediate fish-tetrapod, Tiktaalik, but even so a gap remained between this animal and the earliest true tetrapods (animals with limbs rather than paired fins). Now, new fossils of the extremely primitive tetrapod Ventastega from the Devonian of Latvia cast light on this key phase of the transition.

“Ventastega was first described from fragmentary material in 1994; since then, excavations have produced lots of new superbly preserved fossils, allowing us to reconstruct the whole head, shoulder girdle and part of the pelvis”, says Professor Per Ahlberg at the Department of Physiology and Developmental Biology, Uppsala University.

... more about:
»Ahlberg »Tiktaalik »fossils »tetrapod

The recontructions made by Professor Ahlberg and Assistant Professor Henning Blom together with British and Latvian colleagues show that Ventastega was more fish-like than any of its contemporaries, such as Acanthostega. The shape of its skull, and the pattern of teeth in its jaws, are neatly intermediate between those of Tiktaalik and Acanthostega.

“However, the shoulder girdle and pelvis are almost identical to those of Acanthostega, and the shoulder girdle is quite different from that of Tiktaalik (the pelvis of Tiktaalik is unknown), suggesting that the transformation from paired fins to limbs had already occurred. It appears that different parts of the body evolved at different speeds during the transition from water to land”, says Per Ahlberg.

Per Ahlberg | alfa
Further information:
http://www.uu.se

Further reports about: Ahlberg Tiktaalik fossils tetrapod

More articles from Life Sciences:

nachricht Hopkins researchers ID neurotransmitter that helps cancers progress
25.04.2019 | Johns Hopkins Medicine

nachricht Trigger region found for absence epileptic seizures
25.04.2019 | RIKEN

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Full speed ahead for SmartEEs at Automotive Interiors Expo 2019

Flexible, organic and printed electronics conquer everyday life. The forecasts for growth promise increasing markets and opportunities for the industry. In Europe, top institutions and companies are engaged in research and further development of these technologies for tomorrow's markets and applications. However, access by SMEs is difficult. The European project SmartEEs - Smart Emerging Electronics Servicing works on the establishment of a European innovation network, which supports both the access to competences as well as the support of the enterprises with the assumption of innovations and the progress up to the commercialization.

It surrounds us and almost unconsciously accompanies us through everyday life - printed electronics. It starts with smart labels or RFID tags in clothing, we...

Im Focus: Energy-saving new LED phosphor

The human eye is particularly sensitive to green, but less sensitive to blue and red. Chemists led by Hubert Huppertz at the University of Innsbruck have now developed a new red phosphor whose light is well perceived by the eye. This increases the light yield of white LEDs by around one sixth, which can significantly improve the energy efficiency of lighting systems.

Light emitting diodes or LEDs are only able to produce light of a certain colour. However, white light can be created using different colour mixing processes.

Im Focus: Quantum gas turns supersolid

Researchers led by Francesca Ferlaino from the University of Innsbruck and the Austrian Academy of Sciences report in Physical Review X on the observation of supersolid behavior in dipolar quantum gases of erbium and dysprosium. In the dysprosium gas these properties are unprecedentedly long-lived. This sets the stage for future investigations into the nature of this exotic phase of matter.

Supersolidity is a paradoxical state where the matter is both crystallized and superfluid. Predicted 50 years ago, such a counter-intuitive phase, featuring...

Im Focus: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

High-efficiency thermoelectric materials: New insights into tin selenide

25.04.2019 | Materials Sciences

Salish seafloor mapping identifies earthquake and tsunami risks

25.04.2019 | Earth Sciences

Using DNA templates to harness the sun's energy

25.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>