Navigation Links
Closing the gap between fish and land animals

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.

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.


Contact: Per Ahlberg
Uppsala University

Related biology news :

1. Mechanism explains link between apolipoprotein E and Alzheimers disease
2. Synergy between biology and physics drives cell-imaging technology
3. Environmental peace treaty between Israel and Palestinians unveiled at Ben-Gurion University
4. Analysis of millions of US births shows association between birth defects and preterm birth
5. Scientists discover a molecular scaffold that guides connections between brain cells
6. Study finds possible connection between marijuana abuse and stroke or heart attacks
7. UT researchers find link between advertising and increased tobacco use among Indias youth
8. USC School of Dentistry researchers uncover link between osteoporosis drugs and jaw infection
9. New research shows no link between aromatase inhibitors and cardiovascular problems
10. Possible link between baby swimming and breathing problems in children
11. War between the sexes begins before twins birth, TAU researchers say
Post Your Comments:
(Date:6/15/2016)... ALBANY, New York , June 15, 2016 ... published a new market report titled "Gesture Recognition Market ... Trends and Forecast, 2016 - 2024". According to the ... at USD 11.60 billion in 2015 and is ... and reach USD 48.56 billion by 2024.  ...
(Date:6/7/2016)... June 7, 2016  Syngrafii Inc. and San ... relationship that includes integrating Syngrafii,s patented LongPen™ eSignature ... This collaboration will result in greater convenience for ... union, while maintaining existing document workflow and compliance ... ...
(Date:6/2/2016)... 2, 2016   The Weather Company , an IBM ... an industry-first capability in which consumers will be able to ... ask questions via voice or text and receive relevant information ... Marketers have long sought an advertising solution that ... be personal, relevant and valuable; and can scale across millions ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... , ... June 27, 2016 , ... ... bring innovative medical technologies, services and solutions to the healthcare market. The company's ... of various distribution, manufacturing, sales and marketing strategies that are necessary to help ...
(Date:6/27/2016)... BOSTON , June 27, 2016   Ginkgo ... biology to industrial engineering, was today awarded as ... a selection of the world,s most innovative companies. ... at scale for the real world in the ... organism engineers work directly with customers including Fortune ...
(Date:6/24/2016)... ... June 24, 2016 , ... While the majority of commercial spectrophotometers and fluorometers ... the 6000i models are higher end machines that use the more unconventional z-dimension of ... beam from the bottom of the cuvette holder. , FireflySci has developed several ...
(Date:6/23/2016)... ... 2016 , ... UAS LifeSciences, one of the leading manufacturers ... Probiotics, into Target stores nationwide. The company, which has been manufacturing high quality ... list of well-respected retailers. This list includes such fine stores as Whole Foods, ...
Breaking Biology Technology: