Featured Research

from universities, journals, and other organizations

Shortening tails gave early birds a leg up

Date:
August 13, 2013
Source:
University of Oxford
Summary:
A radical shortening of their bony tails over 100 million years ago enabled the earliest birds to develop versatile legs that gave them an evolutionary edge, a new study shows.

This image shows fossil birds from the time of dinosaurs [left image: Eoenatiornis, right image: Hongshanornis] showing they had diverse types of legs.
Credit: Roger Close

A radical shortening of their bony tails over 100 million years ago enabled the earliest birds to develop versatile legs that gave them an evolutionary edge, a new study shows.

A team led by Oxford University scientists examined fossils of the earliest birds from the Cretaceous Period, 145-66 million years ago, when early birds, such as Confuciusornis, Eoenantiornis, and Hongshanornis, lived alongside their dinosaur kin. At this point birds had already evolved powered flight, necessitating changes to their forelimbs, and the team investigated how this new lifestyle related to changes in their hind limbs (legs).

The team made detailed measurements of early bird fossils from all over the world including China, North America, and South America. An analysis of this data showed that the loss of their long bony tails, which occurred after flight had evolved, led to an explosion of diversity in the hind limbs of early birds, prefiguring the amazing variety of talons, stilts, and other specialised hind limbs that have helped to make modern birds so successful.

A report of the research is published this week in Proceedings of the Royal Society B.

'These early birds were not as sophisticated as the birds we know today -- if modern birds have evolved to be like stealth bombers then these were more like biplanes,' said Dr Roger Benson of Oxford University's Department of Earth Sciences, who led the research. 'Yet what surprised us was that despite some still having primitive traits, such as teeth, these early birds display an incredibly diverse array of versatile legs.'

By comparing measurements of the main parts of the legs of early birds -- upper leg, shin, and foot -- to those of their dinosaur relatives Dr Benson and co-author Dr Jonah Choiniere of the University of the Witwatersrand, South Africa, were able to determine whether bird leg evolution was exceptional compared to leg evolution in dinosaurs.

'Our work shows that, whilst they may have started off as just another type of dinosaur, birds quickly made a rather special evolutionary breakthrough that gave them abilities and advantages that their dinosaur cousins didn't have,' said Dr Rogers. 'Key to this special 'birdness' was losing the long bony dinosaur tail -- as soon as this happened it freed up their legs to evolve to become highly versatile and adaptable tools that opened up new ecological niches.'

It was developing these highly versatile legs, rather than powered flight, that saw the evolutionary diversification of early birds proceed faster than was generally true of other dinosaurs.


Story Source:

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


Journal Reference:

  1. R. B. J. Benson, J. N. Choiniere. Rates of dinosaur limb evolution provide evidence for exceptional radiation in Mesozoic birds. Proceedings of the Royal Society B: Biological Sciences, 2013; 280 (1768): 20131780 DOI: 10.1098/rspb.2013.1780

Cite This Page:

University of Oxford. "Shortening tails gave early birds a leg up." ScienceDaily. ScienceDaily, 13 August 2013. <www.sciencedaily.com/releases/2013/08/130813201426.htm>.
University of Oxford. (2013, August 13). Shortening tails gave early birds a leg up. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/2013/08/130813201426.htm
University of Oxford. "Shortening tails gave early birds a leg up." ScienceDaily. www.sciencedaily.com/releases/2013/08/130813201426.htm (accessed August 23, 2014).

Share This




More Fossils & Ruins News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Neanderthals Probably Died Out Earlier Than We Thought

Neanderthals Probably Died Out Earlier Than We Thought

Newsy (Aug. 21, 2014) — A new study is packed with interesting Neanderthal-related findings, including a "definitive answer" to when they went extinct. Video provided by Newsy
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) — Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
Mother And Son Find Woolly Mammoth Tusks 22 Years Apart

Mother And Son Find Woolly Mammoth Tusks 22 Years Apart

Newsy (Aug. 15, 2014) — A mother and son in Alaska uncovered woolly mammoth tusks in the same river more than two decades apart. Video provided by Newsy
Powered by NewsLook.com
Fossils Reveal Ancient Flying Reptile With 'Butterfly Head'

Fossils Reveal Ancient Flying Reptile With 'Butterfly Head'

Newsy (Aug. 14, 2014) — Newly found fossils reveal a previously unknown species of flying reptile with a really weird head, which some say looks like a butterfly. 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