Featured Research

from universities, journals, and other organizations

High-tech Imaging Of Inner Ear Sheds Light On Hearing, Behavior Of Oldest Fossil Bird

Date:
January 14, 2009
Source:
Ohio University
Summary:
The earliest known bird, the magpie-sized Archaeopteryx, had a similar hearing range to the modern emu, which suggests that the 145 million-year-old creature -- despite its reptilian teeth and long tail -- was more birdlike than reptilian.

Archaeopteryx illustration by John Doncaster.
Credit: Copyright Natural History Museum, London

The earliest known bird, the magpie-sized Archaeopteryx, had a similar hearing range to the modern emu, which suggests that the 145 million-year-old creature — despite its reptilian teeth and long tail — was more birdlike than reptilian, according to new research.

Using innovative modern technology, a team of paleontologists and biologists from London, Munich and Ohio have shown for the first time how the length of the inner ear of birds and reptiles can be used to accurately predict their hearing ability and even aspects of their behavior.

"In modern living reptiles and birds we found that the length of the bony canal containing the sensory tissue of the inner ear is strongly related to their hearing ability," said study co-author Paul Barrett, a palaeontologist at London's Natural History Museum. "We were then able to use these results to predict how extinct birds and reptiles may have heard and found that Archaeopteryx had an average hearing range of approximately 2000 Hz. This means it had similar hearing to modern emus, which have some of the most limited hearing ranges of modern birds."

Researchers previously have only been able to estimate how prehistoric animals heard by examining the skulls of damaged fossils and relating brain region size to hearing ability, based on comparisons to the animals' modern relatives. Computed tomography or CT imaging, however, allowed the team to accurately reconstruct the inner ear anatomy of various intact bird and reptile specimens. Fifty-nine species were studied, including turtles, crocodiles, snakes and birds.

"By examining the three dimensional CT scans we were able to see for the first time the real relationship between hearing ability and behavior in extinct reptiles and birds," said Stig Walsh, Natural History Museum palaeontologist and lead author on the study. "The size of the cochlea duct (the bony part of the inner ear housing the hearing organ) in living birds and reptiles accurately predicts the hearing ranges of these animals. This simple measurement can therefore provide a direct means for determining hearing capabilities, and possibly behavior, in their extinct relatives, including Archaeopteryx."

The study, published in the latest issue of the journal Proceedings of the Royal Society B, also adds more information about how bird-like Archaeopteryx was, said Angela Milner, also from the Natural History Museum. "Our previous research has shown that the part of the ear that controls balance was just like that of modern birds, and now we know that Archaeopteryx had bird-like hearing too," she said.

Other team members included Geoff Manley from the Technical University of Munich, who is a leading scientist in the study of hearing in modern animals, and Lawrence Witmer of Ohio University's College of Osteopathic Medicine in Athens, Ohio. Witmer has studied the structure of the brain and inner ear in dozens of species of dinosaurs and modern and extinct birds, including Archaeopteryx.

"This delicate little inner ear has only recently become a player for those of us trying to interpret the past, because it's buried deep within the skull," said Witmer, whose research is funded by the National Science Foundation. "Thanks to CT scanning, we can now get a clear picture of its structure. It's turned out to be a pretty useful organ for deciphering the lives of extinct animals. My previous research has shown that inner ear structure also can tell us about eye movements, head posture, agility, and the relative importance of hearing, and this new study now shows that this sensory Swiss-army knife can tell us about sociality, vocal complexity and maybe even habitat preference."

Animals with a long cochlear duct tended to have the best hearing and vocal ability. Modern living bird species are known to possess relatively longer cochlear ducts than living reptiles. A long cochlear duct is also an indicator of an individual's complex vocal communication, living in groups and even habitat choice. This is true for both mammals and birds.

"Species that form large social groups have more complicated vocal communication, which is understandably influenced by an individual's ability to hear. Species living in a closed environment where visual communication is ineffective often posses more complex vocal abilities, so now we can more accurately predict the habitat types that extinct animals lived in by examining their ability to hear and communicate," Barrett said.

The research received funding from the Natural Environment Research Council and the National Science Foundation.


Story Source:

The above story is based on materials provided by Ohio University. Note: Materials may be edited for content and length.


Cite This Page:

Ohio University. "High-tech Imaging Of Inner Ear Sheds Light On Hearing, Behavior Of Oldest Fossil Bird." ScienceDaily. ScienceDaily, 14 January 2009. <www.sciencedaily.com/releases/2009/01/090113201350.htm>.
Ohio University. (2009, January 14). High-tech Imaging Of Inner Ear Sheds Light On Hearing, Behavior Of Oldest Fossil Bird. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2009/01/090113201350.htm
Ohio University. "High-tech Imaging Of Inner Ear Sheds Light On Hearing, Behavior Of Oldest Fossil Bird." ScienceDaily. www.sciencedaily.com/releases/2009/01/090113201350.htm (accessed April 24, 2014).

Share This



More Plants & Animals News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Fungus Killing Bats, Spreading in US

Deadly Fungus Killing Bats, Spreading in US

AP (Apr. 24, 2014) A disease that has killed more than six million cave-dwelling bats in the United States is on the move and wildlife biologists are worried. White Nose Syndrome, discovered in New York in 2006, has now spread to 25 states. (April 24) Video provided by AP
Powered by NewsLook.com
Blood From World's Oldest Woman Suggests Life Limit

Blood From World's Oldest Woman Suggests Life Limit

Newsy (Apr. 24, 2014) Scientists say for the extremely elderly, their stem cells might reach a state of exhaustion. This could limit one's life span. Video provided by Newsy
Powered by NewsLook.com
Raw: Kangaroo Rescued from Swimming Pool

Raw: Kangaroo Rescued from Swimming Pool

AP (Apr. 24, 2014) A kangaroo was saved from drowning in a backyard suburban swimming pool in Australia's Victoria state on Thursday. Australian broadcaster Channel 7 showed footage of the kangaroo struggling to get out of the pool. (April 24) Video provided by AP
Powered by NewsLook.com
Could Marijuana Use Lead To Serious Heart Problems?

Could Marijuana Use Lead To Serious Heart Problems?

Newsy (Apr. 24, 2014) A new study says marijuana use could lead to serious heart-related complications. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins