Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Turtles use muscle power to breathe due to rigid shell


Turtle shells are unique in the animal kingdom. In order to be able to breathe in this inflexible casing, tortoises have a muscle sling which is attached to the shell to ventilate the lung.

A team of researchers including paleontologist Torsten Scheyer from the University of Zurich can now reveal that the turtle's ancestor Eunotosaurus africanus already breathed with the aid of such a sling – even though it did not yet have a solid shell. The muscle sling was thus the anatomical prerequisite for the development of the rigid turtle shell.

The present-day extinct ancestors of turtles had a flexible ribcage and breathed, like us, by alternately expanding and contracting the lungs and thorax. The development of a solid shell on the back and belly, however, rendered this kind of respiratory process impossible.

Today’s turtles breathe with the aid of a muscle sling attached to the shell, which contracts and relaxes to aerate the lungs. An international team of researchers from North American, African and European institutes and museums have now discovered the origin of this muscle sling:

in Eunotosaurus africanus, a fossil reptile which lived in South Africa during the Middle Permian around 260 million years ago, as the study just published in Nature Communications reveals.

Instead of a rigid plastron and shell like modern turtles, Eunotosaurus merely had extremely broad, partly overlapping T-shaped ribs. “However, these already heavily restricted the freedom of movement of the ribcage” explains Torsten Scheyer from the Paleontological Institute and Museum of the University of Zurich, who is involved in the study.

Judging by the internal and external bone structures of the ribs, Eunotosaurus evidently only had reduced back muscles, but already possessed a muscle sling that aided respiration. “The small fossil reptile thus provides the explanation as to how the vital adaptation of the breathing apparatus could come about in turtle evolution,” says the UZH paleontologist.

Muscle loop enables shell development

“Eunotosaurus constitutes a morphological link between the body plan of early reptiles and the highly modified body blueprint of the turtles that exist today,” explains Scheyer. The scientists studied the rib plates, so-called costals, of turtle shells and the ribs of various fossil and living vertebrate groups, including mammals, crocodiles and even dinosaurs.

Head of the study Tyler Lyson from the Smithsonian Institution in Washington D.C. and the Denver Museum of Nature and Science, Colorado, adds that, “Based on what we know today, solid shells did not appear in fossil stem turtles until 50 million years after Eunotosaurus.”

The study shows that the steady increase of rigidity of the body wall triggered a separation of the rib and abdominal respiratory muscle functions: The increasing broadening and hardening of the body caused the ribs to become less involved in the respiratory process while the muscles increasingly took over the role. “The ribs became thus free and later completely integrated in the turtle's shell,” says Scheyer.

Lyson, T. R., E. R. Schachner, J. Botha-Brink, T. M. Scheyer, M. Lambertz, G. S. Bever, B. Rubidge, and K. de Queiroz. Origin of the unique ventilatory apparatus of turtles. Nature Communications. November 7, 2014. 5:5211. doi: 10.1038/ncomms6211

Dr. Torsten M. Scheyer
University of Zurich
Paleontological Institute and Museum
8006 Zurich
Tel.: +41 44 634 23 22

Bettina Jakob
Media Relations
University of Zurich
Tel.: +41 44 634 44 39

Weitere Informationen:

Bettina Jakob | Universität Zürich

More articles from Life Sciences:

nachricht ‘Farming’ bacteria to boost growth in the oceans
24.10.2016 | Max-Planck-Institut für marine Mikrobiologie

nachricht Calcium Induces Chronic Lung Infections
24.10.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

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...

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

Oasis of life in the ice-covered central Arctic

24.10.2016 | Earth Sciences

‘Farming’ bacteria to boost growth in the oceans

24.10.2016 | Life Sciences

Light-driven atomic rotations excite magnetic waves

24.10.2016 | Physics and Astronomy

More VideoLinks >>>