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NEWSFILE: PALAENTOLOGY

T.REX`S GREATEST (S)HITS

Thursday, June 18, 1998 A king-sized lump of dinosaur excrement discovered in Canada has set palaeontologists' hearts beating faster with the news that Tyrannosaurus Rex might have been quite a dainty eater. The fossilised faeces - known as a coprolite - was recovered from the Late Cretaceous Frenchman Formation in south-western Saskatchewan. About twice the size of previously discovered dino droppings, it excites scientists because of the secrets it yields on the beast's dining habits. Dr Karen Chin, of the US Geological Survey, and Dr Timothy Tokaryk, of the Royal Saskatchewan Museum, examined the coprolite closely and their findings are published in the science journal, Nature. There are many examples of ancient mammal and avian droppings, but few from the large carnivores. The researchers believe this lump came from the biggest of them all, the T-Rex. Their most striking finding was the large number of bone fragments, a large proportion of its total mass. The researchers were surprised because the fragments suggested that T-Rex pulverised its prey, munching on it up before swallowing. Modern reptiles tend to swallow their prey whole or in large unchewed pieces, as T-Rex was also thought to do. Close scrutiny of the bones showed that the fragments were from young plant-eating dinosaurs, not really a surprise at all. Some of the thicker pieces were thought to have come from a Triceratops, the three-horned beast. The turd itself is 44 cm long, 16 cm across and 13 cm deep. In an accompanying News and Views article in Nature, Drs Peter Andres and Yolanda Fernandez Jalvo, of the Natural History Museum, London, offer much advice on 101 uses for fossilised faeces. They point out that it also gives information on the relationship between predator and prey. It could give information about the plant life of the time seen in pollen grains, either as the stomach contents of the herbivore prey or stuck to the sticky surface of the droppings when they were fresh some 65 million years ago. Rather startlingly, they add that one bone fragment that managed to avoid being pulverised by T-Rex was in such "pristine" condition that "it might be worth looking for DNA in it".

PUT HIM TOGETHER AGAIN

CHICAGO (AP). It may be the largest jigsaw puzzle you'll ever see. Piece by piece, in a high-tech, glass-walled laboratory, Chicago's Field Museum will put together Sue, its prize Tyrannosaurus rex. The lab, on the museum's second floor, was designed to show visitors how fossils are restored. Starting today and for the next two years, it will showcase Sue's resurrection. "The lab is designed to show everyone the process of science, '' said Peter Laraba, a geology specialist in the Field Museum's education department. "As we build Sue, we want to show people, especially kids, how we try to answer the mysteries of one of the most infamous dinosaurs. And ultimately, show them how scientists attack the mysteries of science. '' The 65 million-year-old Sue was discovered in a South Dakota riverbed eight years ago by Chicago-area native Susan Hendrickson. Sue, made up of about 300 bones, is considered the largest and most complete tyrannosaur ever found. The fearsome creature, which cost the museum $8.3 million, should be greeting visitors by 2000. Posing Sue on two legs is actually the easiest part of the entire project, museum staff say. Sue will lean on a self-supporting iron structure and museum scientists already know how the bones fit together. "Once you've seen a bird or a human skeleton, they're all the same, '' said Bill Simpson, who is in charge of putting Sue together. "A vertebrate is a vertebrate, and we know how to put them together pretty easily. What's difficult, what takes the most time, is preparing the bones. '' In the largest of the exhibit's two rooms, two people use small brushes, pencil-sized picks and an air compression device that works like a tiny jackhammer to remove matrix — million-year-old dirt — from fossils.

The matrix is relatively soft and easy to remove but workers still go slowly to avoid scratching or blemishing the skeleton. "I've spent seven weeks on one vertebrae, '' Bob Masek said. "Some bones are more fun to work on than others and each bone calls for a different strategy. It all depends on surface area and shape. '' The final layer of matrix is removed in an adjacent room by a worker who uses an air abrasion machine to blast the dirt away with baking soda. When that's done, the fossils are transformed from a dusty tan shade to dark brown. Elena Polansky, a science and math teacher in Chicago, said a glimpse of the scientific process makes the exhibit invaluable to students. "Children understand science and believe it when they see it, '' she said. "When they get to see the scraping, the dust, the putting together of a real life dinosaur, their minds really get involved. ''

HOMO SURPRISES SCIENTISTS

LOS ANGELES (AP). A million-year-old skull discovered in east Africa suggests human facial features began appearing 300, 000 years earlier than previously believed, researchers say. The well-preserved fossil, lodged in silt and clay in Eritrea, is the only skull found in Africa from between 1. 4 million and 600, 000 years ago, and thus fills in a gap in the fossil record, the researchers said. It combines features of both the human ancestor Homo erectus and modern man, or Homo sapiens, the researchers said. As a result, they aren't ready yet to assign it to one species or the other. The analysis was done by Ernesto Abbate of the University of Florence in Italy and colleagues from South Africa, Switzerland and Eritrea. It was published in Thursday's issue of the journal Nature. Scientists have long debated when, where and how Homo sapiens emerged from more primitive species. Some anthropologists believe that human facial features — that is, Homo sapiens features — did not begin appearing until about 700, 000 years ago.

Homo erectus had a flat skull, a sloping forehead and a thicker brow and smaller brain than Homo sapiens. The skull unearthed in Eritrea bears some of the primitive characteristics of Homo erectus, such as the large brow ridge. But it is like Homo sapiens in one important aspect: The skull is widest at a higher point than skulls of Homo erectus, which are widest near ear level. That could indicate a larger brain. Because the fossil have not yet been fully cleaned, reconstructed and studied, the authors cautioned that their assessment is preliminary. The skull, two lower teeth and two fragments of a pelvis were found in 1995 to 1997 near remains of animals that roamed the African savannah at the time, including three-toed horses. Scientists generally believe Homo sapiens evolved in Africa, then moved toward Europe and Asia. Abbate said the fossil's location in Eritrea, which borders the Red Sea and lies between Ethiopia and Sudan, fits with that theory of northward migration. Outside experts said that if the skull's estimated age is accurate, it fills a gap in the fossil history of Africa. But they questioned the accuracy of the dating method, which relies on variations in magnetic properties of the surrounding rocks. In addition, Richard Sherwood, an anthropologist at the University of Wisconsin at Madison, said it would be hard to draw many conclusions from the preliminary analysis. "To try to link it to Homo sapiens on the basis of one trait is kind of a tenuous association — plus the fact they themselves say the skull has not been reconstructed or studied properly, '' he said.

THE CREATURE WALK(ED) AMONGST US

Wednesday 1 July 1998 NEW YORK (AP) - Fossil-hunters have found remains of the Creature From the Black Lagoon. Not the fish-human hybrid from the 1954 horror flick. No, this one was a lot smaller and looked like a salamander with a big head and feet when it lived by a lake near what is now Edinburgh, Scotland, some 333 million years ago. In Thursday's issue of the journal Nature, Jennifer Clack of Cambridge University in England revealed the creature and her name for it: ``Eucritta melanolimnetes.'' Loosely translated from the Greek and a bit of American slang, that's ``creature from the black lagoon.'' (``Eucritta'' combines ``eu,'' which is an ancient Greek word for ``truth'' or ``goodness,'' and the all-American ``critter.'')

The find includes a nearly complete skeleton measuring about 8 inches from nose to pelvis; it's missing the tail. Clack said the creature apparently grew longer, judging by another recovered skull, but she doesn't know how long. The finding sheds light on the evolution of tetrapods, backboned animals that have four limbs with fingers and toes or are descended from such creatures. Two groups of tetrapods are alive today. One includes mammals, turtles, birds and lizards. The other includes frogs and salamanders. The newfound creature combines traits from both living groups, indicating it lived around the time the two groups split in evolutionary history, Clack said. Scientists have disagreed on when that split happened. The new finding suggests it occurred maybe 340 million years ago, which falls between the dates suggested before, she said. As for what her fellow scientists think of the name, Clack said: ``Some of them really like it. Some of them are a bit sniffy.''

HOLY COWES

A HITHERTO unknown species of dinosaur - a speedy, cat-like creature which combined grace with awesome killing ability - has been discovered on the Isle of Wight. The fossil - up to 16ft long - was found embedded in a cliff on the island’s southern coast. It has taken a year to chisel it from the rock, put the skeleton together and check that there has been nothing like it found anywhere else. The dinosaur, as yet unnamed, had a skull a foot and a half long, murderous claws, razor sharp teeth and long hind legs, which allowed it to run extremely fast. Its very long tail was twice the length of its body and would have acted as a counterweight, switching from side to side as it ran with its head down and its body almost horizontal to the ground.

Steve Hutt, curator at the Isle of Wight Museum of Geology in Sandown, said: "It was a lithe, whippy thing that moved very fast as it hunted different kinds of prey. " It bears some resemblance to Velociraptor, the clawed dinosaur which was one of the stars of the film Jurassic Park. The fossil was found by an amateur collector who brought a claw to Mr Hutt, who said yesterday: "It was a superb claw, a beautiful one. As soon as I saw it, I hit the roof. " He led an excavation and, as the group attacked the cliff with pick axes, chisels and hammers, they realised that they had found a rarity with a peculiar combination of leg-length, arm size, head shape and teeth type.

The dinosaur was unusually well preserved - the teeth were still etched with minute cutting edges. The skeleton would have been swept up in a flood 120 million years ago and later dumped in a depression which then became a pond. The creature is a therapod - a meat-eating dinosaur. "It's definitely a new species, " Mr Hutt said.

SCIENTISTS "HUNCH" MEANS DINO`S GET THE HUMP

SCIENTISTS may have to think again about what some dinosaurs looked like. An American researcher claims that some species may have had a resemblance to today's camels or bison , writes Sean Hargrave. Jack Bailey from Western Illinois University says scientists have the wrong impression of what 28 types of dinosaur looked like. Instead of fan-like "sails" running down their backs or around their necks, he claims many sported humps. Bailey says the humps served the same purpose they do today - to store fat reserves and protect a large animal from the heat of the sun. He struck on the idea two years ago when he saw a bison skeleton and noticed that the bones behind the neck which support its hump were similar to those of some dinosaurs. "They were exactly the sort of spines you find in spinosaurus or ouranosaurus but it has always been presumed that they had sails," he says.

The bones were different to those found on dinosaurs that almost certainly had sails. Rather than being thin and pencil-like, the bonesof some dinosaurs were thicker and slightly larger at the end further away from the body. They also had roughened edges, rather than the smoother ones found on dinosaurs with sails. "It all points to the bones being used to support humps. That is why they are thicker and why they are roughened from where muscle and ligaments have been attached," says Bailey. "Also, these bones are often thinner in the middle which is consistent with bones that have been secured either end and borne a considerable weight, causing the centre to compress and wear."

Humps would have been extremely useful to dinosaurs, he says. "We know that many dinosaurs were migratory. They lived in herds that would consume huge amounts of food and so they would need to move from one source to another. For such animals a hump packed with fat reserves would be essential to provide energy for the journey between feeding grounds. The Cretaceous period, when many of these dinosaurs lived, was one of the hottest times in the past 500m years. So there were these huge animals that could easily have overheated in tropical conditions. If you compare their volume to the skin area where they could let heat escape, you see that they must have had another means of protecting themselves from heat. A hump would have been perfect, allowing heat to be concentrated in an area where thin membranes would have allowed it to dissipate."

If Bailey is correct, palaeontologists will have to reconsider the accepted appearance of 28 types of dinosaur that lived up to 100m years ago. Researchers have always been hampered in their attempts to visualise what dinosaurs were like because they only have bones to work with and no soft tissue. It is for this reason, says Bailey, that it has been widely accepted that the spinal bones growing out from a dinosaur's back were used to support a sail. These served the purpose, it is presumed, of warming up the animal's blood early in the morning. The same sail could then allow heat to escape during midday if shade were found. If there was no protection from the sun, however, the sail was useless. Bailey postulates that this led some dinosaurs to develop humps that would store energy to power the animal while the sun was still warming it up, yet protect it from overheating later in the day.