Featured Research

from universities, journals, and other organizations

Primordial Fish Had Rudimentary Fingers

Date:
September 23, 2008
Source:
Uppsala University
Summary:
Tetrapods, the first four-legged land animals, are regarded as the first organisms that had fingers and toes. Now researchers can show that this is wrong. Using medical x-rays, they found rudiments of fingers in the fins in fossil Panderichthys, the "transitional animal," which indicates that rudimentary fingers developed considerably earlier than was previously thought.

Scientists found rudiments of fingers in the fins in fossil Panderichthys, the “transitional animal,” which indicates that rudimentary fingers developed considerably earlier than was previously thought.
Credit: Image courtesy of Uppsala University

Tetrapods, the first four-legged land animals, are regarded as the first organisms that had fingers and toes. Now researchers at Uppsala University can show that this is wrong. Using medical x-rays, they found rudiments of fingers in the fins in fossil Panderichthys, the "transitional animal," which indicates that rudimentary fingers developed considerably earlier than was previously thought.

The study is published in the journal Nature.

Our fish ancestors evolved into the first four-legged animals, tetrapods, 380 million years ago. They are the forerunners of all all birds, mammals, reptiles and amphibians. Since limbs and their fingers are so important to evolution, researchers have long wondered whether they appeared for the first time in tetrapods, or whether they had evolved from elements that already existed in their fish ancestors.

When they examined genes that are necessary for the evolution of fins in zebrafish (a ray-finned fish that is a distant relative of coelacanth fishes) and compared them with the gene that regulates the development of limbs in mice, researchers found that zebrafish lacked the genetic mechanisms that are necessary for the development of fingers. It was therefore concluded that fingers appeared for the first time in tetrapods. This reading was supported by the circumstance that the fossil Panderichthys, a "transitional animal" between fish and tetrapod, appeared to lack finger rudiments in their fins.

In the present study medical x-rays (CT scans) were used to reconstruct a three-dimensional image of Panderichthys fins. The results show hitherto undiscovered elements that constitute rudiments of fingers in the fins. Similar rudiments have been demonstrated once in the past, two years ago in Tiktaaliks, which is a more tetrapod-like group. Together with information about fin development in sharks, paddlefish, and Australian lungfish, the scientists can now definitively conclude that fingers were not something new in tetrapods.

"This was the key piece of the puzzle that confirms that rudimentary fingers were already present in ancestors of tetrapods," says Catherine Boisvert.


Story Source:

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


Journal Reference:

  1. Catherine A. Boisvert, Elga Mark-Kurik, Per E. Ahlberg. The pectoral fin of Panderichthys and the origin of digits. Nature, 2008; 456 (7222): 636 DOI: 10.1038/nature07339

Cite This Page:

Uppsala University. "Primordial Fish Had Rudimentary Fingers." ScienceDaily. ScienceDaily, 23 September 2008. <www.sciencedaily.com/releases/2008/09/080922090843.htm>.
Uppsala University. (2008, September 23). Primordial Fish Had Rudimentary Fingers. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2008/09/080922090843.htm
Uppsala University. "Primordial Fish Had Rudimentary Fingers." ScienceDaily. www.sciencedaily.com/releases/2008/09/080922090843.htm (accessed September 16, 2014).

Share This



More Plants & Animals News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 Video provided by AFP
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