Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Early mammals used pelvic bones to trot, study finds

17.01.2003


Scientists studying the earliest mammals have been stumped for centuries about the function of two pelvic bones found in the fossil record that most mammals don’t have today. A study published in this week’s issue of the journal Science suggests those bones were involved in locomotion and helped the animals become more mobile, a find that could help researchers pinpoint a key moment in the evolution of mammals.



Biologists at Ohio University and Buffalo State College studied modern-day relations to the earliest mammals — opossums, one of the few types of animals alive today that still has the bones in question, called epipubic bones.

In opossums and a few other marsupials, the epipubic bones are attached to the pelvis and jut into muscles of the stomach. "Kind of like you had two pencils in your belly wall coming from your pelvis up to either side of your navel and they can move up and down," explained Steve Reilly, associate professor of biological sciences at Ohio University and lead author of the study.


Epipubic bones have been found in the earliest mammal fossils and remain in some of the marsupials still living today, and scientists had long thought they supported the animals’ trademark pouch. If that were the case, the bones and attached muscles would move together on one side of the body when the animals walk. But when researchers placed opossums on a treadmill and observed their bones and muscles in motion with a videoflouroscope, they found that the bones move asymmetrically.

"Instead of moving together, one bone is going up and the other is going down," Reilly said. "The epipubic bones act like fishing poles within the belly wall to pull one at a time diagonally across the body, stiffening the body during each trotting step." And, he added, the support from the bones that stiffens the body allowed the animals -- and most likely their ancient ancestors -- to trot.

"These opossums are marsupials that look almost exactly like the fossils we have of mammals that lived millions of years ago," said Reilly, who has studied the evolution of animal locomotion for seven years. "We believe the earliest mammals probably moved just like the opossums because they’re very similar anatomically."

Reilly and his collaborator Thomas White suspect that the development of epipubic bones made the prehistoric creatures more mobile. The increased locomotion made them better predators, helped them to escape predators and allowed them to forage more widely. "Locomotion contributed heavily to the evolution of mammals," Reilly said, "and these bones had something to do with increasing locomotor efficiency in the very earliest mammals."

As the mammals radiated after the dinosaurs went extinct, the epipubic bones in most mammals, including humans, became fused with the pelvis, which allowed mammals to use many gaits besides the trot.

The findings could have implications for paleontologists, Reilly said.

"If the function of the epipubic bone relates to locomotion, that makes the bones more important as a fossil indicator of increased locomotor efficiency," he said. If scientists study the fossil record and figure out when these bones first appeared, he added, it would shed light on a crucial step in the evolution of mammals.

The research is part of a larger study by Reilly and Ohio University colleague Audrone Biknevicius focusing on the evolution of locomotion, which is funded by a three-year, $295,000 National Science Foundation grant.


Written by Kelli Whitlock.

Steve Reilly | EurekAlert!
Further information:
http://www.ohio.edu/researchnews/

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>