Featured Research

from universities, journals, and other organizations

Barren Siberia, Of All Places, May Be Original Home To Animal Life

Date:
April 8, 2004
Source:
University Of Florida
Summary:
Trilobites, the primitive shelled creatures considered by many to be among the first animals to appear in the fossil record, may have originated in a place known today largely for its barren lifelessness: Siberia.

GAINESVILLE, Fla. --- Trilobites, the primitive shelled creatures considered by many to be among the first animals to appear in the fossil record, may have originated in a place known today largely for its barren lifelessness: Siberia.

Related Articles


The finding is one of the conclusions of a two year study by geologists at the University of Florida and University of Kansas that is scheduled to appear next week in the online edition of the London Journal of the Geological Society.

By comparing separate, seemingly unrelated findings on trilobite evolution and geological history, UF's Joe Meert and KU's Bruce Lieberman concluded that precursors to modern continents began splitting off from a giant supercontinent at the South Pole about 580 million years ago, migrating north toward the equator for about 80 million years. The scientists' analysis suggests that a prominent theory holding that the continents moved far more rapidly is wrong. It also suggests that trilobites, the long-ago forbearers of crabs and lobsters, originated in present-day Siberia when it was a separate continent from Asia and located much farther south.

Trilobites probably evolved in Siberia millions of years before they appear in the fossil record, the analysis suggests. In Lieberman's words, their appearance may have supplied the "fuse" for the Cambrian radiation, the "big bang" of life that occurred about 543 million years ago.

"Siberia at the time -- it wasn't as cold and desolate place as it is today," Meert said. "It was in a better place (in the Southern hemisphere) but it's interesting that you can trace roots back."

The study is the fruit of a chance meeting that happened in spring of 2001. Meert was visiting KU to present his research. In what Meert called a "Reese's chocolate-and-peanut-butter moment," the geologists compared notes and realized they had come to the same conclusions about the origins and movement of the modern continents using vastly different methods – one based on the magnetic properties of rocks, the other based on the evolution of trilobites.

When rocks are formed, their magnetic minerals align to the earth's magnetic field, providing Meert the clues he needed to plot the original locations of his specimens on a globe. Carbon dating of radioactive minerals in the rocks also revealed when they were formed. By combining the formation dates with the location data, Meert deduced the whereabouts of the continents over the ages. Lieberman's research, by contrast, focused on using fossil records to study the evolutionary patterns of early life in insects and crustaceans, especially trilobites – the heavily armored, once-common arthropods that left millions of fossils around the globe before their extinction 250 million years ago. These patterns then pointed toward a likely continental breakup and drift scenario.

Working independently, the UF and KU geologists each determined that the southern supercontinent began breaking up around 580 million years ago. The separate continents drifted northward toward the equator at about six inches per year, with this relatively rapid movement ending about 500 million years ago, they found.

Meert's conclusions were based on research on dozens of rocks from locations ranging from Norway to Kenya to Madagascar. Lieberman drew his findings from comparisons of the physical characteristics, such as the number of body segments, of thousands of fossilized trilobites from different continents listed in a KU computer database. By grouping those with similar characters together, he determined where different groups originated and how closely related they were.

While six inches is fast by comparison to today's continental movement of speed of one to two inches per year, it is far slower than that proposed by another prominent theory on early continental movement. That theory, known to scientists as "inertial interchange true polar wander," held the continents rotated from the South Pole to the equator in a mere 15 million years from 523 million to 505 million years ago – meaning they moved at more than 25 inches per year – more than four times faster than what Lieberman and Meert found.

If that were true, Meert said, the expectation would be that all trilobites would be related in the same way – in other words, that their family tree would resemble a bush, with many closely related families together. In fact, some are much more closely related than others, which suggests they split off from and spent differing amounts of time apart from each other, Lieberman said. The analysis also suggests the first trilobite originated on Siberia several million years before the first fossil record of the animals appears. Both studies and methods resulted in the same outcome.

"He had trilobites on my paleogeography and I had palegeography on his trilobites," Meert said.

Although the cause of the Cambrian radiation remains unknown, the continents' movement away from one another opened a new ocean between them and probably warmed the climate, creating an atmosphere more conducive to life, Meert added.


Story Source:

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


Cite This Page:

University Of Florida. "Barren Siberia, Of All Places, May Be Original Home To Animal Life." ScienceDaily. ScienceDaily, 8 April 2004. <www.sciencedaily.com/releases/2004/04/040408085320.htm>.
University Of Florida. (2004, April 8). Barren Siberia, Of All Places, May Be Original Home To Animal Life. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2004/04/040408085320.htm
University Of Florida. "Barren Siberia, Of All Places, May Be Original Home To Animal Life." ScienceDaily. www.sciencedaily.com/releases/2004/04/040408085320.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Fossils & Ruins News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Bring Player Pianos Back to Life

Researchers Bring Player Pianos Back to Life

AP (Dec. 17, 2014) Stanford University wants to unlock the secrets of the player piano. Researchers are restoring and studying self-playing pianos and the music rolls that recorded major composers performing their own work. (Dec. 17) Video provided by AP
Powered by NewsLook.com
Domestication Might've Been Bad For Horses

Domestication Might've Been Bad For Horses

Newsy (Dec. 16, 2014) A group of scientists looked at the genetics behind the domestication of the horse and showed how human manipulation changed horses' DNA. Video provided by Newsy
Powered by NewsLook.com
Mozart, Beethoven, Shubert and Bizet Manuscripts to Go on Sale

Mozart, Beethoven, Shubert and Bizet Manuscripts to Go on Sale

AFP (Dec. 16, 2014) A collection of rare manuscripts by composers Mozart, Beethoven, Shubert and Bizet are due to go on sale at auction on December 17. Duration: 00:57 Video provided by AFP
Powered by NewsLook.com
Old Ship Records to Shed Light on Arctic Ice Loss

Old Ship Records to Shed Light on Arctic Ice Loss

Reuters - Innovations Video Online (Dec. 15, 2014) Researchers are looking to the past to gain a clearer picture of what the future holds for ice in the Arctic. A project to analyse and digitize ship logs dating back to the 1850's aims to lengthen the timeline of recorded ice data. Ben Gruber reports. Video provided by Reuters
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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