(Phys.org)—The chance discovery of a 100 million year old fossil forest on an island east of New Zealand has unlocked new insights on ancient life close to the South Pole.
Large trees in their original living position, early flowering plants, seed cones and rare insects preserved in a rock formation were discovered by researchers in the Chatham Islands. The find reveals what is believed to be the first records of life close to the South Pole during the Cretaceous period, a time of extreme greenhouse conditions 145-65 million years ago.
Led by palaeontologist Associate Professor Jeffrey Stilwell and palaeobotanist Dr Chris Mays from Monash University's School of Geosciences, a research team including Professor David Cantrill from the Royal Botanic Gardens Melbourne made the discovery.
Associate Professor Stilwell said the fossils painted a picture of the formerly unknown life of the Cretaceous period when many southern continents including New Zealand and the Chatham Islands (Zealandia), Australia, Antarctica and South America were still mostly joined together as part of the southern landmass Gondwana.
"One hundred million years ago, the Earth was in the grip of a greenhouse effect – a planet of extreme heat with minimal ice (except in the high altitudes) and sea levels of up to 200 metres higher than today," Associate Professor Stilwell said.
"Rainforests inhabited by dinosaurs existed in sub-polar latitudes and polar ecosystems were adapted to long months of winter darkness and summer daylight.
"Never before have we had evidence about what life existed near the South Pole 90 to 100 million years, or the conditions that life on land experienced.
The discovery, 865 kilometres east of New Zealand, was made in one the most remote fossil locations known in the Southern Hemisphere while researchers were investigating a bone bed further north on Chatham Island and plant remains on nearby Pitt Island.
"Until now there was no modern analogue to this type of preserved forest as close to the South Pole at approximately 1200 kilometres, which is the equivalent distance between Melbourne and Brisbane," Dr Mays said.
"The discovery attests to a completely different type of ecosystem around 100 million years ago revealing the first insights into specific strategies these plants and animals evolved to cope with extreme greenhouse conditions, and months of light and alternating darkness."
Dr Mays said although no immediate comparisons could be drawn, the insights of life on Earth during past greenhouse conditions could provide clues as to how plants and animals will adapt to global warming in the future.
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Lurker2358
2.8 / 5 (10) Dec 27, 2012I don't get that part.
there is only enough water-ice on Earth to raise sea levels by about 100 meters, and I calculated this would cause affected lands to sink at a ratio of about 1 to 6, making up about another 15 to 17 meters of net rise. this leaves 83 meters of additional sea level rise needed to explain 200 meters.
Is all of that 83 meters from thermal expansion?!
k_m
3.5 / 5 (8) Dec 27, 2012"If all the ice covering Antarctica, Greenland, and in mountain glaciers around the world were to melt, sea level would rise about 70 meters (230 feet)."
Arcbird
1 / 5 (9) Dec 27, 2012barakn
4.4 / 5 (7) Dec 27, 2012lessee90229
2.3 / 5 (4) Dec 27, 2012obama_socks
1 / 5 (6) Dec 27, 2012In the picture, the hills in the background may be the remains of mountains that wind and rain have excavated. The forests would have covered the tall mountains up to the tree line, even if the sea level was 200 meters higher than today. Fossil trees would have slid down the mountains toward lower areas. Interesting find!!
bbrhuft2
5 / 5 (1) Dec 27, 2012Faster seafloor spreading rates during the early-Cretaceous continental breakup created large areas of younger less dense oceanic crust, resulting in shallow ocean basins that held less water; this as well as ice free Poles contributed to the increased sea levels.
Seton, M. et al. 2009. Mid-Cretaceous seafloor spreading pulse: Fact or fiction? Geology, 37(8), 687
Sinister1811
2.5 / 5 (8) Dec 27, 2012Peteri
not rated yet Dec 28, 2012nkalanaga
5 / 5 (2) Dec 28, 2012Sinister1811
1.7 / 5 (6) Dec 28, 2012That's a shame. Anyways, thanks for the correction.
Dt_C_P_Trivedi India
1 / 5 (5) Dec 30, 2012Max Planck Society Germany has reported under their project climap that 18000 years ago green house effect and subsequent global warming and ice age was there on the earth, both are same or different.
The Vedas have the reference of Global warming also, if it is confirmed than Vedas may guide further about origin of life.and consciousness in early primitive condition. The Higgs Boson and DNA were discovered in the same fashion as we have discovered.
Dt_C_P_Trivedi India
1 / 5 (5) Dec 30, 2012Looking to the depth of the Vedic knowledge in the light of modern science, it seems that the Vedic culture may have flourished on the earth before the ice age and 'Green house Effect' and consequent Global warming had forced them to compile their knowledge in Vedic hymns.
El_Nose
not rated yet Dec 31, 2012What about all the underground aquifers. There is a quadrillion gallon freshwater reservoir under the middle of the US that has been providing water for the bread basket for generations.
Hot Rod
not rated yet Jan 01, 2013Jonseer
1 / 5 (4) Jan 01, 2013Perhaps, but one estimate for the total rise in sea levels should ALL the ice melt on all land masses including Antarctica and Greenland is over 500 ft.
Most lower estimates assume that SOME ice would remain in the more remote reaches of East Antarctica and/or Greenland.
The warm Cretaceous had none of that.
There were NO ice caps anywhere on the planet, and the only permanent ice would have been in high elevations where the the low temperatures are independent of climate.
Global maps of that era show oceans covering large areas of our present day continents.
Jonseer
1 / 5 (4) Jan 01, 2013Instead of assuming, how about just doing some simple math and figure out how much 3 millimeters/annually X 90 million years equals.
3 millimeters is a very conservative amount in regards to the uplift or settling of land even by today's rather slow pace of plate tectonics.
90 million years is about the middle of the Cretaceous give or take a few million.
On the geological time scale the #s you think extreme are nothing.
In fact they are so small, you have to assume that the island in question has risen and fallen during that time.