Fossil Science
Recent News |  Archives |  Tags |  About |  Newsletter |  Submit News |  Links |  Subscribe to FossilScience.com RSS Feed Subscribe


More Articles
Discovery hints at why stress is more devastating for someDiscovery hints at why stress is more devastating for some

An uphill climb for mountain species?An uphill climb for mountain species?

'Solid' light could compute previously unsolvable problems'Solid' light could compute previously unsolvable problems

Molecular self-assembly controls graphene-edge configurationMolecular self-assembly controls graphene-edge configuration

Team identifies important regulators of immune cell responseTeam identifies important regulators of immune cell response

Researchers develop ultra sensitive biosensor from molybdenite semiconductorResearchers develop ultra sensitive biosensor from molybdenite semiconductor

Childhood mentors have positive impact on career successChildhood mentors have positive impact on career success

Blood-cleansing biospleen device developed for sepsis therapyBlood-cleansing biospleen device developed for sepsis therapy

Asian monsoon much older than previously thoughtAsian monsoon much older than previously thought

The ozone hole has stabilized -- some questions remainThe ozone hole has stabilized -- some questions remain

Evolutionary tools improve prospects for sustainable developmentEvolutionary tools improve prospects for sustainable development

Researchers discover new clues to determining the solar cycleResearchers discover new clues to determining the solar cycle

Missing piece found to help solve concussion puzzleMissing piece found to help solve concussion puzzle

In directing stem cells, study shows context mattersIn directing stem cells, study shows context matters

Hydrogen powers important nitrogen-transforming bacteriaHydrogen powers important nitrogen-transforming bacteria

Computer games give a boost to EnglishComputer games give a boost to English

Pesky insect inspires practical technologyPesky insect inspires practical technology

Mapping the DNA sequence of Ashkenazi JewsMapping the DNA sequence of Ashkenazi Jews

News media losing role as gatekeepers to new 'social mediators' on Twitter, study findsNews media losing role as gatekeepers to new 'social mediators' on Twitter, study finds

An 'anchor' that keeps proteins togetherAn 'anchor' that keeps proteins together

Biologists delay the aging process by 'remote control'Biologists delay the aging process by 'remote control'

Milk prices top concern of Northeastern organic dairy farmersMilk prices top concern of Northeastern organic dairy farmers

Cicada study discovers 2 genomes that function as 1Cicada study discovers 2 genomes that function as 1

Bombarded by explosive waves of information, scientists review new ways to process and analyze Big DataBombarded by explosive waves of information, scientists review new ways to process and analyze Big Data

Program earns kudos for improving grades, retaining studentsProgram earns kudos for improving grades, retaining students

Geography matters: Model predicts how local 'shocks' influence U.S. economyGeography matters: Model predicts how local 'shocks' influence U.S. economy

A healthy lifestyle adds years to lifeA healthy lifestyle adds years to life

Identified for the first time what kind of explosive has been used after the detonationIdentified for the first time what kind of explosive has been used after the detonation

Copied from nature: Detecting software errors via genetic algorithmsCopied from nature: Detecting software errors via genetic algorithms

Rare Antarctic Fosssils In Mountain Lake Area Reveal Extinction Of Tundra Before Full Polar-Climate Arrived (8/6/2008)

Tags:
climate change, diatoms, moss, plants

Freeze-dried terrestrial vegetation and insects help to reveal the ecological legacy of a unique global climate transition

An international research team in Antarctica led by David Marchant, an associate professor of earth sciences at Boston University, has reported the discovery of exceptionally well-preserved freshwater fossils including mosses, microscopic one-celled algae, known as diatoms, small fresh water crustaceans, and insects that represent the last traces of tundra in the southernmost region of the continent before a dramatic and enduring cooling occurred some 14 million years ago.

These rare fossilized terrestrial organisms, from the McMurdo Dry Valleys sector of the Transantarctic Mountains, were uncovered in sediments from a former ice-free lake, which served to pinpoint the inception of modern polar-desert conditions in Antarctica. The fossil discoveries are also the first to be found in the area even though other scientific expeditions have been visiting this southern region since the first expedition more than 100 years ago.

"The fossils and surrounding sediments are extremely well preserved," said Marchant. "They tell us that the landscape has changed very little in 14.1 million years, and that at the time the fossils lived the climate in this sector of Antarctica was similar to that of southern South America today. The organisms died out suddenly by 13.9 million years ago, and since that time interior Antarctica has been in a perpetual deep freeze, with most of the interior ice remaining relatively stable and frozen. The exact cause of this dramatic climatic shift, one of the most significant over the last 65 million years, remains unknown"

Marchant's comments follow the August 4th publication of "Mid-Miocene Cooling and the Extinction of Tundra in Continental Antarctica" in the Proceedings of the National Academy of Science.

Marchant, along with Adam R. Lewis, a former Boston University graduate student (Ph.D,2005) who discovered the fossils while working under Marchant, are the first of 13 authors on the paper. These research collaborators are from other universities in the U.S., Canada, United Kingdom, Sweden, Germany and New Zealand*. The research was funded by the National Science Foundation.**

Like dried museum specimens, these freeze-dried fossils can be rehydrated. They are among the best preserved specimens from this age found anywhere on Earth, noted Marchant. Some species are identical to modern counterparts, and the dominant moss species is indistinguishable from an existing bryophyte (Drepanocladus longifolius). This type of morphologic stability is nearly unheard of in the fossil record.

Between the stems and leaves of the mosses, the researchers found exceptionally well preserved ostracods, tiny crustaceans whose soft parts are not typically found in the fossil record. "In addition to fossils of organisms that inhabited the lake, we have recovered pollen and spores, and a few macroscopic remains of plants and insects that inhabited the lake regions," the paper states.

"Everything about the fossil site, from its geology to the fossils themselves, tells us the climate shift was abrupt, major, and enduring. Its legacy continues to this day," said Marchant, noting that researchers combined evidence from computer modeling, glacial geology, dating of volcanic ashes, and paleoecology to determine the major climate shift centered ~14 million years ago.

The authors maintain that the dramatic and long-lasting climate changes – summer temperatures in the McMurdo Dry Valleys as much as 17 degrees warmer than the present-day average -- are associated with the extinction of tundra and insects, such as beetles and midges.

The paper's conclusion suggests that even when global atmospheric temperatures were warmer than they are now – as they were around 3.5 million years ago, and as they may be in the future due to global warming -- the fossil site remained cold and dry. One of the take-home messages is that climate conditions over a considerable fraction of Antarctica seem impervious to moderate global warming. This finding highlights the potentially complex and non-uniform response of Antarctic ice sheets to future global change.

Founded in 1839, Boston University is an internationally recognized institution of higher education and research. With more than 30,000 students, it is the fourth largest independent university in the United States. BU contains 17 colleges and schools along with a number of multi-disciplinary centers and institutes which are central to the school's research and teaching missions.

*The other authors are Allan C. Ashworth, Lars Hedenas, Sidney R. Hemming, Jesse V. Johnson, Melanie J. Leng, Malka L. Machlus, Angela E. Newton, J. Ian Raine, Jane K. Willenbring, Mark Williams and Alexander P. Wolfe.

Note: This story has been adapted from a news release issued by Boston University

Post Comments:

Search
New Articles
Study traces ecological collapse over 6,000 years of Egyptian history

Enigmatic Viking fortress discovered in DenmarkEnigmatic Viking fortress discovered in Denmark

It's the pits: Ancient peach stones offer clues to fruit's originsIt's the pits: Ancient peach stones offer clues to fruit's origins

T. rex times 7: New dinosaur species is discovered in ArgentinaT. rex times 7: New dinosaur species is discovered in Argentina

Team unveils Dreadnoughtus: A gigantic, exceptionally complete sauropod dinosaurTeam unveils Dreadnoughtus: A gigantic, exceptionally complete sauropod dinosaur

How good is the fossil record?

Ancient mammal relatives were active at night 100 million years before origin of mammalsAncient mammal relatives were active at night 100 million years before origin of mammals

Scientists create renewable fossil fuel alternative using bacteria

Exceptionally well preserved insect fossils from the Rhône ValleyExceptionally well preserved insect fossils from the Rhône Valley

Plant life forms in the fossil record: When did the first canopy flowers appear?Plant life forms in the fossil record: When did the first canopy flowers appear?

The Disappearing Spoon author Sam Kean takes on the megalodon mythThe Disappearing Spoon author Sam Kean takes on the megalodon myth

Ancient metal workers were not slaves but highly regarded craftsmenAncient metal workers were not slaves but highly regarded craftsmen

Paleontology: Oldest representative of a weird arthropod group

Stone-tipped spears more damaging than sharpened wooden spearsStone-tipped spears more damaging than sharpened wooden spears

Bronze Age wine cellar found



Archives
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007


Science Friends
Agricultural Science
Astronomy News
Biology News
Biomimicry Science
Cognitive Research
Chemistry News
Tissue Engineering
Cancer Research
Cybernetics Research
Electonics Research
Forensics Report
Genetic Archaeology
Genetics News
Geology News
Microbiology Research
Nanotech News
Parenting News
Physics News


  Archives |  Submit News |  Advertise With Us |  Contact Us |  Links
Use of this site constitutes acceptance of our Terms of Service and Privacy Policy. All contents © 2000 - 2015 Web Doodle, LLC. All rights reserved.