Featured Research

from universities, journals, and other organizations

Oldest Australian Crayfish Fossils Provide Missing Evolutionary Link

Date:
February 12, 2008
Source:
Emory University
Summary:
Crayfish body fossils and burrows discovered in Victoria, Australia, have provided the first physical evidence that crayfish existed on the continent as far back as the Mesozoic Era, according to paleontologists. During that era, diverse plants grew in what is today Antarctica and dinosaurs roamed in prolonged polar darkness along southern Australia river plains.

Early Cretaceous (115 million-year-old) crayfish burrow systems preserved as natural sandstone casts near the Dinosaur Dreaming dig site, Victoria, Australia. Scale = 10 centimeters.
Credit: Photo by Anthony Martin

Crayfish body fossils and burrows discovered in Victoria, Australia, have provided the first physical evidence that crayfish existed on the continent as far back as the Mesozoic Era, says Emory University paleontologist Anthony Martin, who headed up a study on the finds.

"Studying the fossil burrows gives us a glimpse into the ecology of southern Australia about 115 million years ago, when the continent was still attached to Antarctica," says Martin, a senior lecturer in environmental studies at Emory and an honorary research associate at Monash University in Melbourne.

During that era, diverse plants grew in what is today Antarctica and dinosaurs roamed in prolonged polar darkness along southern Australia river plains. The period is of particular interest to scientists since it is believed to be the last time the Earth experienced pronounced global warming, with an average temperature of 68 degrees Fahrenheit – just 10 degrees warmer than today.

The crayfish body fossils consist of an abdomen and two claws, and the fossil burrows are nearly identical to those made by modern crayfish in southeastern Australia. "Comparing these fossil burrows to those made by modern crayfish in Australia shows us that their behavior hasn't changed that much," says Martin, who specializes in trace fossils.

Biologists have long been fascinated by crayfish, due to their wide range – the freshwater decapods are found on almost every continent and have adapted to extremely diverse environments. Thomas Huxley, a colleague of Charles Darwin, was the first scientist to ponder how crayfish, which cannot survive in saltwater, could have spread to so many continents, according to Martin.

Such studies helped lay the groundwork for plate tectonics, which revolutionized the earth sciences in the 1960s through the theory that the continents were once connected. More recently, molecular biologists have theorized that all Southern Hemisphere crayfish originated in southeastern Australia.

"The evolution of Southern Hemisphere crayfish has challenged researchers since the 1870s," Martin says. "Only now, 140 years later, are we starting to put together the physical evidence for this evolution through the discovery of fossils."

On Feb. 2, the earth science journal Gondwana Research published online the results of the crayfish study, which was conducted by Martin and a consortium of Australian scientists, including Thomas Rich and Gary Poore of the Museum of Victoria; Mark Schultz and Christopher Austin of Charles Darwin University; and Lesley Kool and Patricia Vickers-Rich of Monash.


Story Source:

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


Cite This Page:

Emory University. "Oldest Australian Crayfish Fossils Provide Missing Evolutionary Link." ScienceDaily. ScienceDaily, 12 February 2008. <www.sciencedaily.com/releases/2008/02/080206175537.htm>.
Emory University. (2008, February 12). Oldest Australian Crayfish Fossils Provide Missing Evolutionary Link. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2008/02/080206175537.htm
Emory University. "Oldest Australian Crayfish Fossils Provide Missing Evolutionary Link." ScienceDaily. www.sciencedaily.com/releases/2008/02/080206175537.htm (accessed September 22, 2014).

Share This



More Fossils & Ruins News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Iconic 'Easy Rider' Chopper Bike to Go on Auction Block

Iconic 'Easy Rider' Chopper Bike to Go on Auction Block

AFP (Sep. 19, 2014) The iconic Harley-Davidson motorbike ridden by Peter Fonda in the 1969 classic "Easy Rider" is to go under the hammer in California, and auctioneers predict it will make at least $1 million. Duration: 01:09 Video provided by AFP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Egypt Denies Claims Oldest Pyramid Damaged in Restoration

Egypt Denies Claims Oldest Pyramid Damaged in Restoration

AFP (Sep. 17, 2014) Egypt's antiquities minister denied Tuesday claims that the Djoser pyramid, the country's first, had been damaged during restoration work by a company accused of being unqualified to do such work. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com
King Richard III's Painful Cause Of Death Revealed

King Richard III's Painful Cause Of Death Revealed

Newsy (Sep. 17, 2014) King Richard III died in the Battle of Bosworth in 1485, and now researchers examining his skull think they know how. 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