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PARIS (AFP) – Ancient fossilized teeth of small anthropoid monkeys discovered in Libya suggest our earliest ancestors may have migrated from Asia to Africa, research published Wednesday showed. The origin of anthropoids -- primates including monkeys, apes and humans -- has long been a source of hot debate among palaeontologists. Experts have long argued anthropoids first appeared in Africa -- but recent studies suggest an earlier Asian origin, dating 55 million years ago. Now new fossils, dating 38 to 39 million years ago and discovered in Dur At-Talah in central Libya, further complicate the debate. They reveal the existence of...

Hot blobs of magma - the searing liquid rock beneath the Earth's crust - can spread slow-moving ripples that soar hundreds of meters high across the Earth's surface, a new study suggests. This phenomenon, which works on geologic time scales, may explain relatively rapid pre-historical changes in sea level that occurred without the typical waxing and waning of the polar ice sheets, which hold and release water on scales of thousands and millions of years. This unexplained sea level rise is one of geology's oldest mysteries. During the Paleogene era (65 million to 23 million years ago), the land under...

The continent-hopping habits of early primates have long puzzled scientists, and several scenarios have been proposed to explain how the first true members of the group appeared virtually simultaneously on Asia, Europe and North America some 55 million years ago. But new research using the latest evidence suggests a completely different migration path from those previously proposed and indicates that sudden, rapid global warming drove the dispersal. Researchers from the University of Michigan, Johns Hopkins University School of Medicine and the Royal Belgian Institute of Natural Sciences present their findings in the July 25 issue of the Proceedings of the...

Volcanic eruptions caused global temperature spike 55 million years ago By Alan Zarembo, Times Staff Writer 1:03 PM PDT, April 26, 2007 Scientists believe they have solved the mystery of what caused the most rapid global warming in known geologic history, a cataclysmic temperature spike 55 million years ago driven by concentrations of greenhouse gases hundreds of times greater than today. The culprit, the researchers reported Thursday in the journal Science, was a series of volcanic eruptions that set off a chain reaction releasing massive quantities of carbon into the atmosphere. The eruptions occurred on the rift between two continental...

Global warming 55 million years ago suggests a high climate sensitivity to carbon dioxide, according to research led by Mark Pagani, associate professor of geology and geophysics at Yale and published in the December 8 issue of Science. For some years, scientists have known that a massive release of carbon into the atmosphere caused the ancient global warming event known as the Paleocene-Eocene Thermal Maximum (PETM) that began about 55 million years ago. The geologic record shows that the resulting greenhouse effect heated the planet as a whole by about 9 F (5 C), in less than 10,000 years. That...

A runaway spurt of global warming 55 million years ago turned Earth into a hothouse but how this happened remains worryingly unclear, scientists said on Monday. Previous research into this period, called the Palaeocene-Eocene Thermal Maximum, or PETM, estimates the planet's surface temperature blasted upwards by between five and nine degrees Celsius (nine and 16.2 degrees Fahrenheit) in just a few thousand years. The Arctic Ocean warmed to 23 C (73 F), or about the temperature of a lukewarm bath. How PETM happened is unclear but climatologists are eager to find out, as this could shed light on aspects of...

A rapid rise in temperature on ancient Earth triggered a climate response that may have prolonged the warming for many thousands of years, according to scientists. Their study, published online in Nature Geoscience, provides new evidence of a climate feedback that could explain the long duration of the Paleocene-Eocene Thermal Maximum (PETM), which is considered the best analogue for modern climate change. The findings also suggest that climate change today could have long-lasting impacts on global temperature even if humans are able to curb greenhouse gas emissions. "We found evidence for a feedback that occurs with rapid warming that can...

First collected in southwestern Wyoming in a fossil site known as the Green River Formation, Eocypselus rowei lived about 50 million years ago. It was a small creature about 12 cm long (from head to tail), and weighed less than an ounce... The fossil is unusual in having exceptionally well-preserved feathers, which allowed the researchers to reconstruct the size and shape of the bird’s wings in ways not possible with bones alone. Feathers account for more than half of the bird’s total wing length... The analysis suggests that the bird was an evolutionary precursor to the group that includes today’s...

An ancient global warming event shrunk the earliest horses down to the size of scrawny housecats, according to new research that could have implications for what mammals might look like in a future warming world. During what's known as the Paleocene-Eocene Thermal Maximum, or PETM, about 56 million years ago, a massive release of carbon into the atmosphere and oceans boosted average global temperatures by about 10 degrees Fahrenheit (5.5 degrees Celsius) over 175,000 years. Mammals responded to this climate change by shrinking, with about one-third of species getting smaller. Now, new research reveals that these changes occurred in lockstep...

Scientists drilling deep into the edge of modern Antarctica have pulled up proof that palm trees once grew there. Analyses of pollen and spores and the remains of tiny creatures have given a climatic picture of the early Eocene period, about 53 million years ago. The study in Nature suggests Antarctic winter temperatures exceeded 10C, while summers may have reached 25C. Better knowledge of past "greenhouse" conditions will enhance guesses about the effects of increasing CO2 today. The early Eocene - often referred to as the Eocene greenhouse - has been a subject of increasing interest in recent years as...

Thirty-eight million years ago, tropical jungles thrived in what are now the cornfields of the American Midwest and furry marsupials wandered temperate forests in what is now the frozen Antarctic. The temperature differences of that era, known as the late Eocene, between the equator and Antarctica were half what they are today. A debate has been ongoing in the scientific community about what changes in our global climate system led to such a major shift from the more tropical, greenhouse climate of the Eocene to modern and much cooler climates. New research results published in this week's issue of the...

Analyses of pelagic limestones indicate that the flux of extraterrestrial helium-3 to Earth was increased for a 2.5-million year (My) period in the late Eocene. The enhancement began ~1 My before and ended ~1.5 My after the major impact events that produced the large Popigai and Chesapeake Bay craters ~36 million years ago. The correlation between increased concentrations of helium-3, a tracer of fine-grained interplanetary dust, and large impacts indicates that the abundance of Earth-crossing objects and dustiness in the inner solar system were simultaneously but only briefly enhanced. These observations provide evidence for a comet shower triggered by an...

Scientists use deep ocean historical records to find an abrupt ocean circulation reversalNewly published research results provide evidence that global climate change may have quickly disrupted ocean processes and lead to drastic shifts in environments around the world. Although the events described unfolded millions of years ago and spanned thousands of years, the researchers, affiliated with the Scripps Institution of Oceanography, say they provide one of the few historical analogs for warming-induced changes in the large-scale sea circulation, and thus may help to illuminate the potential long-term impacts of today's climate warming. Writing in this week's issue of the journal...