Featured Research

from universities, journals, and other organizations

Major Fossil Find Reveals Asian Origins Of Salamanders

Date:
April 3, 2001
Source:
University Of Chicago Medical Center
Summary:
A 150 million-year-old Chinese fossil site provides an extraordinary new window on the origin of one of the major groups of living amphibians. More than 500 fossils, many of which preserve the entire skeleton and impressions of soft tissues provide compelling evidence that the salamander originated in Asia according to a report in the March 29, 2001 issue of Nature.

A 150 million-year-old Chinese fossil site provides an extraordinary new window on the origin of one of the major groups of living amphibians. More than 500 fossils, many of which preserve the entire skeleton and impressions of soft tissues provide compelling evidence that the salamander originated in Asia according to a report in the March 29, 2001 issue of Nature.

"All the major primitive salamander families are now known to be present in Asia," said Neil Shubin, professor and chairman of organismal biology and anatomy of the University of Chicago. "The simple, take-home, message is that there is an Asian origin for all salamanders."

"The diversity of species in this find, combined with molecular data and study of characteristics from living salamanders, leads to the inescapable conclusion that almost all the major groups of salamanders evolved very early," said Shubin, "And not much has been happening since."

"These fantastic Northern Chinese sites are providing us with a wealth of new fossils," said Keqin Gao, of the American Museum of Natural History in New York. "The same set of beds provided evidence of feathered dinosaurs."

Salamanders, one of the three major groups of modern amphibians, are important to understanding fundamental questions in evolution. Their wide geographic distribution, highly variable species and ecological diversification have served as a model system for assessing developmental, anatomical and biogeographic evolution.

"There has been a huge gap in the fossil record. The origin of salamanders was poorly documented, the fossil evidence was just inadequate," said Gao. "We only had fossils of the extant salamander families going back to the Tertiary, 65 million years ago."

A volcanic eruption in northern China during the Late Jurassic, 150 million years ago, provided key material for the origin of the salamander--85 million year earlier than the previous fossil record. The eruption wiped out whole communities of the earliest known salamanders but left hundreds of beautifully preserved fossils.

Complete fossils, some including rare soft tissue impressions, offer a wealth of new information of the salamander's origin, life-cycle and evolutionary strategies.

"We were able to see all the stages of the life cycle, larvae and adults, as well as a range of different kinds of animals," said Shubin. "The exquisite condition of the fossils offers clues to evolutionary strategies--larval details such as gills in adult animals, for example."

Salamanders are living fossils--they have retained the same body plan for millions of years. "Whether you look at a salamander you find under a rock in the local forest preserve or in a rock in China dating back 150 million years, they look alike. In fact, they look alike in great detail--the bones in their wrists are the same, the way their skulls are formed--intricate details are the same," said Shubin.

At the same time, their limbs and heads have served as a model of how variation arises during evolution. One of the great puzzles of evolution is how different types of salamanders evolved the same features independently. This phenomenon is called parallel evolution. These fossils may provide answers to this old question.

Neoteny, the retention of juvenile characteristics in the adult animal, is extremely important to the generation of diversity among salamanders. More than 40 salamander species in nine families display features of neoteny. The Chinese salamanders reveal that generating diversity through neoteny was already established by 150 million years ago, which may explain why parallel evolution is so common in salamanders.

Despite their longevity over evolutionary time, salamanders today are disappearing worldwide. "Here is an animal that has been around for at least 150 million years. They made it through several major extinction events. They made it through the event that killed the dinosaurs," said Shubin. "Yet today, along with other amphibians, salamanders are disappearing and we really don't know why."

Field work was supported by the National Geographic Society and the Frick Funds of the American Museum of Natural History.


Story Source:

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


Cite This Page:

University Of Chicago Medical Center. "Major Fossil Find Reveals Asian Origins Of Salamanders." ScienceDaily. ScienceDaily, 3 April 2001. <www.sciencedaily.com/releases/2001/03/010329075404.htm>.
University Of Chicago Medical Center. (2001, April 3). Major Fossil Find Reveals Asian Origins Of Salamanders. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2001/03/010329075404.htm
University Of Chicago Medical Center. "Major Fossil Find Reveals Asian Origins Of Salamanders." ScienceDaily. www.sciencedaily.com/releases/2001/03/010329075404.htm (accessed July 28, 2014).

Share This




More Fossils & Ruins News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Did ISIS Destroy Jonah's Tomb?

Did ISIS Destroy Jonah's Tomb?

Newsy (July 25, 2014) Unverified footage posted to YouTube purportedly shows ISIS militants destroying a shrine widely believed to be the tomb of the prophet Jonah. Video provided by Newsy
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Richard III's Car Park Burial Site Opens to Public

Richard III's Car Park Burial Site Opens to Public

AFP (July 25, 2014) Visitors will be able to look down from a glass walkway on the grave of King Richard III when a new centre opens in the English cathedral city of Leicester, where the infamous hunchback was found under a car park in 2012. Duration: 00:35 Video provided by AFP
Powered by NewsLook.com
Mobile App Gives Tour of Battle of Atlanta Sites

Mobile App Gives Tour of Battle of Atlanta Sites

AP (July 25, 2014) Emory University's Center for Digital Scholarship has launched a self-guided mobile tour app to coincide with the 150th anniversary of the Civil War's Battle of Atlanta. (July 25) Video provided by AP
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