Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Mass extinction led to many new species of bony fish


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.

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.

Dr. Carlo Romano
Paleontological Institute and Museum
University of Zurich
Tel: +41 634 23 47

Weitere Informationen:

Nathalie Huber | Universität Zürich

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>