Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mass extinction led to many new species of bony fish

01.12.2014

With over 30,000 species worldwide, the ray fins are currently the largest group of fish. These bony fish were not always as numerous, however. Losses of other fish species, such as cartilaginous fish, helped them to spread successfully. As paleontologists from the University of Zurich together with international researchers reveal, a series of serious extinction events between 300 to 200 million years ago played a central role in the development of today’s fish fauna.

Today, ray-finned fish, which belong to the bony fish, are by far the most biodiverse fish group in both salt- and freshwater. Their spectacular variety of forms ranges from eels, tuna, flounders and angler fish all the way to seahorses.


after severe losses among cartilaginous fishes during the Middle Permian extinction, bony fishes experienced a massive diversification in the subsequent Trias period.

Picture: University of Zurich


The picture shows the Triassic ray-finned fish Saurichthys with two embryos (close-up).

Picture: University of Zurich

With around 1,100 species, the second most biodiverse group is the cartilaginous fish, which are almost exclusively marine and include sharks, rays and chimaeras. Exactly why bony fish managed to prevail in different habitats is the subject of debate: Do they have a better body plan, which is suited to more ecological niches than that of the cartilaginous fish? Or are other factors involved in their successful distribution? Paleontologists from the University of Zurich now reveal that climate catastrophes in the past played a crucial role in the dominance of ray-finned fish today.

Cartilaginous fish greatly depleted by extinction events
The scientists studied the changes in biodiversity among cartilaginous and bony fish during the Permian and Triassic periods around 300 to 200 million years ago – an interval marked by several serious extinction events. They evaluated the global scientific literature on bony and cartilaginous fish from the last 200 years and collected data on diversity and body size, the latter providing an indication of the fish’s position in the food chains in the seas and freshwater.

Based on the data evaluated, the researchers demonstrate that cartilaginous fish, the most biodiverse fish group at the time, especially suffered heavily during an extinction event in the Middle Permian epoch while the Permian ray-finned fish escaped relatively unscathed. After an even bigger mass extinction close to the Permian-Triassic boundary, which wiped out 96 percent of all sea organisms, these bony fish diversified heavily.

Of the ray-finned fish, the so-called Neopterygii (“new fins”) became particular biodiverse during the Triassic and, with over 30,000 species, today constitute the largest vertebrate group. Triassic Neopterygii primarily developed small species while the majority of the more basal ray-fins produced large predatory fish. Moreover, many bony fish developed morphological specializations in the Triassic, such as in the jaw apparatus, dentition or fins. This enabled new ways of locomotion, including gliding over the surface of the water, much like flying fish do today. Moreover, there is also evidence for viviparity in Triassic bony fish, for the first time ever.

Extinction events correlate with climate changes
Unlike bony fish, cartilaginous fish, which had already been heavily decimated by the end of the Permian, did not really recover. Many groups that were still biodiverse in the Permian disappeared completely or became extremely rare during the extinction events of the Permian and the Triassic. “Our results indicate that repeated extinction events played a key role in the development of today’s fish fauna,” explains Carlo Romano, a postdoc at the University of Zurich’s Paleontological Institute and Museum. Most of these severe crises are linked to massive volcanic activity, global climate changes and sea level lowstands.


Literature:
C. Romano, M. B. Koot, I. Kogan, A. Brayard, A. V. Minikh, W. Brinkmann, H. Bucher, J. Kriwet, Permian-Triassic Osteichthyes (bony fishes). Diversity dynamics and body size evolution. Biological Reviews, November 28, 2014. S. 1-44. doi: 10.1111/brv.12161.


Contacts:
Dr. Carlo Romano
Paleontological Institute and Museum
University of Zurich
Tel: +41 634 23 47
Email: carlo.romano@pim.uzh.ch


Weitere Informationen:

http://www.mediadesk.uzh.ch

Nathalie Huber | Universität Zürich

More articles from Life Sciences:

nachricht Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>