This video is called Life in Cenozoic Times.
Reuters reports:
WASHINGTON - Details on the largest climate change since the age of dinosaurs come straight from the horse’s mouth, as equine teeth provide clues to how long, how cold and when the big chill was, scientists reported Wednesday.See also here.Earth’s temperature dropped by 15 degrees F over a period of 400,000 years some 33.5 million years ago, the researchers said in the current edition of the journal Nature. …
Paleontologists have known for more than a century that many species went extinct at the transition between the Eocene and Oligocene, based on the fossil record before and after the shift.
However, they lacked the analytic tools to determine how much temperature change there was over how long a period, and exactly when it occurred.
Fossil research showed that creatures that might be at home in the tropics, like warm-loving crocodilians, roamed what is now Nebraska on the American Great Plains before the temperature transition.
After the transition, they were gone.
Scientists believe changes in ocean currents were to blame for the shift.
To figure out the details of what French researchers dubbed Grande Coupure — “big cut” — MacFadden and his co-authors examined the preserved teeth and bones of fossil horses and another cloven-hoofed mammal called an oreodont. …
Ice during the Oligocene: here.
Pleistocene Horses in the New World: here.
Przewalski’s horse: here.
Clalicotherium etc. fossils, here.
A giant rhinocerotoid (Mammalia, Perissodactyla) from the Late Oligocene of north-central Anatolia (Turkey): here.
PALEONTOLOGY PRIZE: Ancient oreodont quite a find for N.M. location
03/09/2008 01:58:37 PM EDT
Albuquerque Journal (NM) (KRT)
Mar. 9–The mouth grinned out of the canyon wall at Dave Love, a vision from the distant past. Love was on a geologic scouting expedition when he spotted it, 8 feet up from the canyon floor, embedded in a layer of sandstone.
“Lo and behold, there was this nice set of teeth,” recalled Love, a geologist with the New Mexico Bureau of Geology.
The teeth were attached to a jaw, which was attached to a skeleton, which drew a group of scientists back to the desert canyon March 4 for a little digging.
The creature that drew all this fuss might not have been worthy of much note when it wandered an ancient proto-New Mexico. But, today, the rare find provides a window into a time when our modern landscape was just taking shape.
The sheeplike creature, called an oreodont, made its living munching plants, explained Gary Morgan, a curator at the New Mexico Museum of Natural History and Science.
Morgan led the team that dug the fossil out of the canyon wall, bringing it back to the Museum of Natural History in Albuquerque for study.
Love and two colleagues were scouting the area Feb. 22 for a geologic mapping project when they saw the fossil, embedded in the canyon wall east of the visitors’ center at Bosque del Apache, south of Socorro.
The creature had been entombed in the rock since its death, more than 10 million years ago, according to Morgan.
What we now call “New Mexico” was very different then. To the north, the Rocky Mountains had already risen, but state’s central mountain chain, from the Sandia Mountains south, was nowhere to be seen.
More important for the shape of our landscape today, there was no Rio Grande. Instead, according to Love, there was a series of inland basins, with no river flowing to the sea.
The oreodont — the name is derived from the words for “mountain” and “tooth,” though no one quite knows why — lived among a fauna very much like what you would see on the African savanna today — a grassland with clumps of trees along the river, according to Morgan.
There were elephantlike creatures then, along with rhinos and eight different kinds of camels, he said.
On first glance, the teeth embedded in the rock looked to Love like they belonged to a camel. But when Morgan arrived, it was immediately apparent they belonged instead to an oreodont.
From a scientific perspective, that is a bonus, Morgan said. Camels are common in the area, but no one has ever found an oreodont there.
“The rarer the animal,” Morgan said, “the more interesting to me.”
Comment by Administrator — March 26, 2008 @ 12:39 pm