Two forms of world’s ‘newest’ cat


By Matt Walker
Editor, Earth News

The “newest” cat species described to science, the Sunda clouded leopard, actually exists in two distinct forms, scientists have confirmed.

This big cat is so enigmatic that researchers only realised it was a new species – distinct from clouded leopards living elsewhere in Asia – in 2007. The first footage of the cat in the wild to made public was only released last year.

Now a genetic analysis has confirmed that the cat comes in two forms, one living in Sumatra, the other on Borneo.

Clouded leopards are the most elusive of all the big cats, which include lions, tigers, jaguars, snow leopards and normal spotted leopards.

Living across south-east Asia, into China and India, the leopards have larger cloud-like spots than ordinary leopards.

Until 2006, all clouded leopards were thought to belong to a single species.

However, genetic studies revealed that there are actually two quite distinct clouded leopard species.

As well as the better known clouded leopard living on the Asian mainland ( Neofelis nebulosa ), scientists determined that a separate clouded leopard species lives on the islands of Borneo and Sumatra.

The two species are thought to have diverged over one million years ago.

This leopard is now known as the Sunda clouded leopard ( Neofelis diardi ), though it was previously and erroneously called the Bornean clouded leopard.

Since 2008, it has been listed as vulnerable by the International Union for the Conservation of Nature.

In 2010, a team of scientists working in the Dermakot Forest Reserve in Malaysia released the first footage of the cat in the wild to be made public.

Led by Mr Andreas Wilting of the Leibniz Institute for Zoo and Wildlife Research in Berlin, Germany, the researchers captured images of a Sunda clouded leopard walking along a road.

Now Mr Wilting and colleagues have published new research which reveals even more about this mysterious cat.

They sampled 15 Sunda clouded leopards living on Borneo and 16 living in Sumatra, conducting molecular and genetic studies to reveal their origin.

The researchers also examined the skulls of 28 further Sunda clouded leopards and the fur coats of 20 specimens held in museums, as well as the coats of cats photographed on both islands.

“Although we suspected that Sunda clouded leopards on Borneo and Sumatra have likely been geographically separated since the last Ice Age, it was not known whether this long isolation had caused them to split up into separate sub-species,” explains Wilting.

But his team’s analysis confirms that the latest “new” species of cat to be discovered actually comes in two forms, a Bornean subspecies N. d. borneensis and the Sumatran subspecies N. d. diardi .

Their results are published in the journal Molecular Phylogenetics and Evolution.

The differences aren’t obvious: the Sunda clouded leopards on Borneo and Sumatra look alike.

Both cats have similar patterned coats as they live in similar jungle habitats, the researchers suspect.

But as well as being genetically distinct, the clouded leopards on both islands are also morphologically different, having unique features in their skulls and teeth.

It is unclear what caused the Sunda clouded leopard to evolve into two forms.

“So far we can only speculate about the specific course of events in the evolution of the clouded leopard,” says team member Joerns Fickel, also at the Leibniz Institute for Zoo and Wildlife Research.

But the researchers think that a volcanic eruption on Sumatra 75,000 years ago may have wiped out most clouded leopards.

One group survived in China and colonised the rest of mainland Asia.

Another hung on in Borneo, becoming the Sunda clouded leopard. This evolved into two types after a group colonised Sumatra via glacial land bridges, and then became cut off as sea levels rose.

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/earth/hi/earth_news/newsid_9369000/9369238.stm

Published: 2011/01/22 20:10:55 GMT

© BBC 2011

Early T. Rex ancestor found in South America


By RANDOLPH E. SCHMID, AP Science Writer Randolph E. Schmid, Ap Science Writer
Thu Jan 13, 6:23 pm ET

WASHINGTON – Back at the dawn of the dinosaur era, a quick-moving predator set the stage for the famous and fearsome giants that followed in its footsteps, according to new research. “It was a little dinosaur, but it carried a big evolutionary stick,” said Paul C. Sereno of the University of Chicago, a leader of the team that discovered Eodromaeus.

The 4-foot-long hunter lived 230 million years ago in what is now South America and appears to be the ancestor of such creatures as Tyrannosaurus rex.

“It is stunning,” Sereno said of the find, reported in Friday’s edition of the journal Science.

Its features, such as a balancing tail and air pockets in the skull, show it was closely related to T. rex, he said.

But while it stood on two feet like T. rex, Eodromaeus (pronounced eyo-DRO-may-us) was a lightweight at just 10- to 15-pounds.

“This is a very exciting find indeed,” said Oliver W. M. Rauhut, a curator at the Bavarian State Collection for Palaeontology and Geology in Munich, Germany.

“The origin and early diversification of dinosaurs is still poorly understood,” said Rauhut, who was not on the research team.

Nick Longrich of the department of geology and geophysics at Yale University agreed: “It’s very significant, because it helps give us a better idea of what the ancestor of carnivorous dinosaurs — including Tyrannosaurus, Allosaurus and the birds — would have looked like.”

“A new species of early dinosaur is always an exciting find, especially when the specimens are so complete, like Eodromaeus,” added Randall B. Irmis, a professor of geology and geophysics at the University of Utah.

It shares many features with an early carnivorous dinosaur named Tawa from New Mexico and reported last year by Irmis and colleagues.

The similarity supports the idea that these early carnivorous dinosaurs moved between North and South America during the Late Triassic period, said Irmis, who was not part of Sereno’s research team.

In addition to the discovery of Eodromaeus — which means dawn runner — the researchers proposed reclassifying a previously known dinosaur called Eoraptor.

It was similar in size to Eodromaeus, but differences in the teeth indicate Eoraptor more likely was an ancestor of the giant plant-eating sauropod dinosaurs than the hunting theropods like T. rex with which it had been associated, according to Sereno, Paul N. Martinez of the National University of San Juan in Argentina, and their co-authors.

“The reclassification of Eoraptor actually makes perfect sense … the teeth have always made me wonder,” said Longrich, who was not on the research team.

Added Longrich, “this paper helps sort out the origin of several major groups — the big carnivores like T. rex, the birds, and the giant plant eaters like Apatosaurus,” formerly known as Brontosaurus.

The new find brings scientists to within a few million years of the original “Eve” dinosaur, Sereno commented. But now the search gets elusive because of the lack of bones below the level where Eodromaeus was found.

Lower, there are footprints but not bones, Sereno said.

The Eodromaeus’ fossils were discovered in the late 1990s in the Ischigualasto formation in northeastern Argentina.

___

Online: http://www.sciencemag.org

Ancient human remains found in Israel

By DANIEL ESTRIN, Associated Press Daniel Estrin, Associated Press
Mon Dec 27, 6:13 pm ET
JERUSALEM –

Israeli archaeologists said Monday they may have found the earliest evidence yet for the existence of modern man, and if so, it could upset theories of the origin of humans.

A Tel Aviv University team excavating a cave in central Israel said teeth found in the cave are about 400,000 years old and resemble those of other remains of modern man, known scientifically as Homo sapiens, found in Israel. The earliest Homo sapiens remains found until now are half as old.

“It’s very exciting to come to this conclusion,” said archaeologist Avi Gopher, whose team examined the teeth with X-rays and CT scans and dated them according to the layers of earth where they were found.

He stressed that further research is needed to solidify the claim. If it does, he says, “this changes the whole picture of evolution.”

The accepted scientific theory is that Homo sapiens originated in Africa and migrated out of the continent. Gopher said if the remains are definitively linked to modern human’s ancestors, it could mean that modern man in fact originated in what is now Israel.

Sir Paul Mellars, a prehistory expert at Cambridge University, said the study is reputable, and the find is “important” because remains from that critical time period are scarce, but it is premature to say the remains are human.

“Based on the evidence they’ve cited, it’s a very tenuous and frankly rather remote possibility,” Mellars said. He said the remains are more likely related to modern man’s ancient relatives, the Neanderthals.

According to today’s accepted scientific theories, modern humans and Neanderthals stemmed from a common ancestor who lived in Africa about 700,000 years ago. One group of descendants migrated to Europe and developed into Neanderthals, later becoming extinct. Another group stayed in Africa and evolved into Homo sapiens — modern humans.

Teeth are often unreliable indicators of origin, and analyses of skull remains would more definitively identify the species found in the Israeli cave, Mellars said.

Gopher, the Israeli archaeologist, said he is confident his team will find skulls and bones as they continue their dig.

The prehistoric Qesem cave was discovered in 2000, and excavations began in 2004. Researchers Gopher, Ran Barkai and Israel Hershkowitz published their study in the American Journal of Physical Anthropology.

Early Sauropod Dinosaur: First Complete Skeleton Found

ScienceDaily (Oct. 28, 2010)

Skull and lower jaw of Yizhousaurus, an early sauropod dinosaur from the Lower Jurassic (~200-million-years-old) of southern China.
(Credit: Bill Mueller)

Scientists have discovered in China the first complete skeleton of a pivotal ancestor of Earth’s largest land animals — the sauropod dinosaurs. The new species, tentatively dubbed Yizhousaurus sunae, lived on the flood plains around Lufeng in the Yunnan Province of South China about 200 million years ago. The species helps explain how the iconic four-footed, long-necked sauropod dinosaurs evolved.

Unlike the 120-foot-long, 100-ton sauropod giants that came later, Yizhousaurus was about 30 feet in length, but it shows all of the hallmarks of later sauropods: the beginning of a long neck, a robust skeleton and four-legged posture. It also comes with an intact fossilized skull — which is very rare and crucial for understanding its place in the evolution of sauropods.

“Sauropods have these big bones but their skulls are very lightly constructed and also very small,” said paleontologist Sankar Chatterjee of Texas Tech University. Chatterjee presents the discovery on Oct. 31 at the annual meeting of the Geological Society of America in Denver.

Yizhousaurus’s skull is broad, high and domed, less than a foot long with a short snout, eye sockets on the sides for scanning enemies. It has an unusually wide and U-shaped jaw, in top view, like that seen in later Camarasaurus, said Chatterjee. Numerous serrated and spoon-shaped teeth of the upper and lower jaws would shear and slide past each other for cutting plant material during feeding. The sturdy teeth and raised neck let the animal very easily nip small branches from treetops and then chew the plant material.

“Once the plant food was ingested, a gastric mill in the stomach probably provided further mechanical breakdown of the plant,” Chatterjee explained. Apparently the animal was well adapted to a life of eating plants to support its large body.

Besides its telltale physical features, Yizhousaurus was also found in revealing company. A half century ago spectacular specimens of prosauropod dinosaurs such as Lufengosaurus were discovered at the same location. This makes sense, since most paleontologists are of the opinion that prosauropods gave rise to sauropods, despite the fact that the transition has been very vague, Chatterjee said.

“This is why this new one (Yizhousaurus), may bridge this gap,” he said.

Abstract is available at http://gsa.confex.com/gsa/2010AM/finalprogram/abstract_175675.htm