Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

260 Million-Year-Old Reptiles from Russia Possessed the First Modern Ears

12.09.2007
The discovery of the first anatomically modern ear in a group of 260 million-year-old fossil reptiles significantly pushes back the date of the origin of an advanced sense of hearing, and suggests the first known adaptations to living in the dark.

In a new study published in PLoS ONE, Johannes Müller and Linda Tsuji, paleobiologists at the Natural History Museum of the Humboldt University in Berlin, Germany report that these fossil animals, found in deposits of Permian age near the Mezen River in central Russia, possessed all the anatomical features typical of a vertebrate with a surprisingly modern ear.

When vertebrates had conquered land and the ancestors of modern day mammals, reptiles, and birds first began to diversify, hearing was not of high importance. The first fully terrestrial land vertebrates were, in fact, largely deaf, and lacked any of the anatomical features that would indicate the possession of what is termed impedance-matching hearing - the mechanism by which modern land vertebrates are able to transmit airborne sounds into the inner ear by means of small bony connections.

The ability of modern animals to hear a wide range of frequencies, highly important for prey capture, escape, and communication, was long assumed to have only evolved shortly before the origin of dinosaurs, not much longer than 200 million years ago, and therefore comparatively late in vertebrate history.

... more about:
»Fossil »hear »hearing »reptiles »vertebrate

But these fossils demonstrate that this advanced ear was in existence much earlier than previously suggested. In these small reptiles the outside of the cheek was covered with a large eardrum, and a bone comparable to our own hearing ossicles connected this structure with the inner ear and the brain. Müller and Tsuji also examined the functional performance of this unique and unexpected auditory arrangement, and discovered that these little reptiles were able to hear at least as well as a modern lizard.

But why would these animals have possessed such an ear? “Of course this question cannot be answered with certainty”, explains Müller, “but when we compared these fossils with modern land vertebrates, we recognized that animals with an excellent sense of hearing such as cats, owls, or geckos, are all active at night or under low-light conditions.

And maybe this is what these Permian reptiles did too." Because the fossils from the Mezen River also possess comparatively large eyes, another typical feature of vertebrates living in the dark, these reptiles indeed might have been among the first land vertebrates to pursue a specifically nocturnal lifestyle. An adaptation of this kind would have been a significant step at this early stage of terrestrial evolution, as endothermic (cold-blooded) animals require the heat of the sun to maintain their body temperature.

The discovery of an ear comparable to modern-day standards in such ancient land vertebrates provides an entirely new piece of information about the earliest terrestrial ecosystems, which no longer seem to be as primitive as once assumed. Already by this time, there must have been intense pressure to exploit new ecological niches and to evolve new structures to gain an advantage over other species in an increasingly crowded world. At last, it was those pressures and evolutionary inventions that paved the way for our modern day environments.

Andrew Hyde | alfa
Further information:
http://www.plosone.org/doi/pone.0000889

Further reports about: Fossil hear hearing reptiles vertebrate

More articles from Life Sciences:

nachricht Plankton swim against the current
12.12.2017 | Schweizerischer Nationalfonds SNF

nachricht To differentiate or not to differentiate?
12.12.2017 | Max-Planck-Institut für Biologie des Alterns

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Midwife and signpost for photons

11.12.2017 | Physics and Astronomy

How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas

11.12.2017 | Earth Sciences

PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

11.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>