Paleontology news

The unusually intact fossilized skull of a giant, bony-toothed seabird that lived up to 10 million years ago was found on Peru's arid southern coast, researchers said Friday.

The fossil is the best-preserved cranium ever found of a pelagornithid, a family of large seabirds believed to have gone extinct some 3 million years ago, said Rodolfo Salas, head of vertebrate paleontology at Peru's National History Museum.

The museum said in a statement that the birds had wingspans of up to 20 feet (6 meters) and may have used the toothlike projections on their beaks to prey on slippery fish and squid. But studying members of the Pelagornithidae family has been difficult because their extremely thin bones — while helpful for keeping the avian giants aloft — tended not to survive as fossils.

"Its fossils are very strange, very rare and very hard to find," Salas told The Associated Press.

The cranium discovered in Peru is 16 inches (40 centimeters) long and is believed to be 8 million to 10 million years old, based on the age of the rock bed in which it was found.

"Rarely are any bones of these gigantic, marine birds found fossilized uncrushed, and to find an uncrushed skull of this size is very significant," said Ken Campbell, curator of vertebrate zoology at the Natural History Museum of Los Angeles.

Campbell, who examined photos of the find but was not involved in the dig, said he knows of "no specimen of comparable quality."

Dan Kepska, a paleontology researcher at North Carolina State University who also was not part of the project, agreed that the skull is the most complete ever reported.

He called the birds "one of the great enigmas of avian paleontology."

With fossils discovered in North America, North Africa and even Antarctica, Kepska said, the birds were ubiquitous only a few million years before humans evolved and scientists puzzle over why they died out. Some believe they are related to gannets and pelicans, while other say they are related to ducks.

Campbell said the Peru find "will undoubtedly be of great importance to our understanding of these gigantic birds, and it will help clarify the relationships of the other fossil pelagornithids found in the Pisco Formation."

The formation, a coastal rock bed south of the capital, Lima, is known for yielding fossils of whales, dolphins, turtles and other marine life dating as far back as 14 million years.

credited to news.yahoo.com

Paleontologists working in Peru have found a fossil from a bird that lived 10 million years ago, scientists said on Friday after returning from the dig site on the country's desert coast.

The species of bird had a wingspan of 19.7 feet and fed mostly on fish from the Pacific Ocean. It first appeared 50 million years ago and was extinct about 2.5 million years ago because of climate change, paleontologist Mario Urbina of Peru's Natural History Museum said.

Scientists discovered a rare fossil of the bird's head in Ocucaje, in the Ica region of Peru's southern coast, where an arid climate has preserved many fossils.

"The cranium of the bird, from the Pelagornithidae family, is the most complete find of its kind in the world. Its fossil remains are hard to find," Urbina said.

Old ocean seabeds in the area have been a treasure trove for fossil hunters.

"This site had marine sediments. The fossil was found with other remains from whales, sharks and turtles," Urbina said.

At the time of the bird's death, Peru's coast was hot and rainy, but millions of years later, it turned cool and dry, he said.

The fossil is 15.7 inches long and will go on display on Saturday at the museum.

The bird had some peculiar characteristics, including teeth at the tip of its beak and large wings that were less efficient than those of contemporary birds.

"The teeth helped capture its prey. This was an animal that perhaps trapped its prey and chewed while it flew. It had a hard time taking off from the ground, and needed an elevated point to take off from," Urbina said.

credited to msnbc.msn.com

Roman artefacts which are nearly two thousand years old with similarities to ancient remains found at Pompeii in Italy have been examined at the Science and Technology Facilities Council's ISIS neutron source (21-22 February). Researchers are hoping to learn more about our heritage by discovering whether the items were imported from southern Italy, or manufactured using similar techniques in Britain. The bronze artefacts, which include a wine-mixing vessel, jugs and ceremonial pan-shaped objects, were discovered in Kent in two high status Roman pit-burials that are among the best examples ever seen in Britain. Previous excavation in an area close to the A2 where the items were found - by construction group Skanska Civil Engineering during a Highways Agency road improvement scheme - had predicted archaeological discoveries, but they were bigger than expected, with settlements ranging from the Bronze Age to the late medieval period.

Archaeological scientists have been comparing the 1st Century AD artefacts from Kent with those from Pompeii in Italy. The neutron beams at the world-leading ISIS facility allow for detailed crystal structure analysis of intact delicate objects without cutting out a sample of the material.

Dana Goodburn-Brown, a conservator and ancient metals specialist commissioned by Oxford Archaeology, has been analysing the artefacts along with archaeological scientist Dr. Evelyne Godfrey at ISIS to see how they were made. It is hoped results from the experiments will answer many questions about how the items were made to give more insight into their origin: for example, the metals used in manufacturing, how they were cast and finished, and how metal pieces were joined together.

''Our experiments will hopefully aid us in characterising different Roman metalworking practices and perhaps recognising the distinction between imported south Italian goods and high standard copies produced by skilled local craftsman. These artefacts represent a time of great change in Britain - they appear shortly after the Romans arrived in this country, and may represent locals taking on cultural practices of these 'newcomers," Dana Goodburn-Brown said.

Dr Andrew Taylor, ISIS Director said: "For these rare and highly-valued objects, analysis with neutrons can give fantastic insight. Neutrons are a very powerful way to look at matter at the molecular level and they give unique results that you can't easily get with any other technique. The measurements are extremely delicate and non-destructive, so the objects are unharmed by the analysis and can be returned to the museums unscathed.

The neutron beams we have at ISIS are a very versatile research tool and we're always keen to help researchers answer a broad range of questions. Here we realised that we could take the same analysis methods we developed to look at parts of aircraft and power plants and use them to help archaeologists understand how ancient objects were traded and manufactured."

credited to esciencenews.com

A missing link in the evolution of the front claw of living scorpions and horseshoe crabs was identified with the discovery of a 390 million-year-old fossil by researchers at Yale and the University of Bonn, Germany. The specimen, named Schinderhannes bartelsi, was found fossilized in slate from a quarry near Bundenbach in Germany, a site that yields spectacularly durable pyrite-preserved fossils — findings collectively known as the Hunsrück Slate. The Hunsrück Slate has previously produced some of the most valuable clues to understanding the evolution of arthropods – including early shrimp-like forms, a scorpion and sea spiders as well as the ancient arthropods trilobites.

"With a head like the giant Cambrian aquatic predator Anomalocaris and a body like a modern arthropod, the specimen is the only known example of this unusual creature," said Derek Briggs, director of Yale's Peabody Museum of Natural History and an author of the paper appearing in the journal Science.

Scientists have puzzled over the origins of the paired grasping appendages found on the heads of scorpions and horseshoe crabs. The researchers suggest that Schinderhannes gives a hint. Their appendages may be an equivalent to those found in the ancient predatory ancestor, Anomalocaris — even though creatures with those head structures were thought to have become extinct by the middle of the Cambrian Period, 100 million years before Schinderhannes lived.

The fossil's head section has large bulbous eyes, a circular mouth opening and a pair of segmented, opposable appendages with spines projecting inward along their length. The trunk section is made up of 12 segments, each with small appendages, and a long tail spine. Between the head and trunk, there is a pair of large triangular wing-like limbs — that likely propelled the creature like a swimming penguin, according to Briggs. Unlike its ancestors from the Cambrian period, which reached three feet in length, Schinderhannes is only about 4 inches long.

This finding caps almost 20 years of study by Briggs on the Hunsrück Slate. "Sadly, the quarry from which this fabulous material comes has closed for economic reasons, so the only additional specimens that are going to appear now are items that are already in collectors' hands and that may not have been fully prepared or realized for what they are," said Briggs.

credited to esciencenews.com

June 30, 1908, 7:14 a.m., central Siberia—Semen Semenov, a local farmer, saw “the sky split in two. Fire appeared high and wide over the forest.... From ... where the fire was, came strong heat.... Then the sky shut closed, and a strong thump sounded, and I was thrown a few yards.... After that such noise came, as if . . . cannons were firing, the earth shook ...”

Such is the harrowing testimony of one of the closest eyewitnesses to what scientists call the Tunguska event, the largest impact of a cosmic body to occur on the earth during modern human history. Semenov experienced a raging conflagration some 65 kilometers (40 miles) from ground zero, but the effects of the blast rippled out far into northern Europe and Central Asia as well. Some people saw massive, silvery clouds and brilliant, colored sunsets on the horizon, whereas others witnessed luminescent skies at night—Londoners, for instance, could plainly read newsprint at midnight without artificial lights. Geophysical observatories placed the source of the anomalous seismic and pressure waves they had recorded in a remote section of Siberia. The epicenter lay close to the river Podkamennaya Tunguska, an uninhabited area of swampy taiga forest that stays frozen for eight or nine months of the year.

Ever since the Tunguska event, scientists and lay enthusiasts alike have wondered what caused it. Although most observers generally accept that some kind of cosmic body, either an asteroid or a comet, exploded in the sky above Siberia, no one has yet found fragments of the object or any impact craters in the affected region. The mystery remains unsolved, but our research team, only the latest of a steady stream of investigators who have scoured the area, may be closing in on a discovery that will change our understanding of what happened that fateful morning.

The study of the Tunguska event is important because past collisions with extraterrestrial bodies have had major effects on the evolution of the earth. Some 4.4 billion years ago, for example, a Mars-size planetoid seems to have struck our young planet, throwing out enough debris to create our moon. And a large impact may have caused the extinction of the dinosaurs 65 million years ago. Even today cosmic impacts are evident. In July 1994 several astronomical observatories recorded the spectacular crash of a comet on Jupiter. And only last September, Peruvian villagers watched in awe and fright as a heavenly object streaked across the sky and landed not too far away with a loud boom, leaving a gaping pit 4.5 meters deep and 13 meters wide.

Using satellite observations of meteoric “flares” in the atmosphere (“shooting stars”) and acoustical data that record cosmic impacts on the surface of the earth, Peter Brown and his co-workers at the University of Western Ontario and Los Alamos National Laboratory estimated the rate of smaller impacts. The researchers have also extrapolated their findings to larger but rarer incidents such as the Tunguska event. The average frequency of Tunguska-like asteroidal collisions ranges from one in 200 years to one in 1,000 years. Thus, it is not unlikely that a similar strike could occur during our lifetimes. Luckily, the Tunguska impact took place in an unpopulated corner of the globe. Should something like it explode above New York City, the entire metropolitan area would be razed. Understanding the Tunguska event could help us prepare for such an eventuality and maybe even take steps to avoid its occurrence altogether.

The first step in preparing ourselves would be to decide whether the cosmic object that affected Siberia was an asteroid or a comet. Although the consequences are roughly comparable in either case, an important difference is that objects in the solar system that circle far away from the sun on long-period orbits before returning, such as comets, would hit the earth at much greater velocities than close-orbiting (short-period) bodies, such as asteroids. A comet that is significantly smaller than an asteroid thus could release the same kinetic energy in such a collision. And observers have much more difficulty detecting long-period objects before they enter the inner solar system. In addition, the probability that such objects will cross the earth’s orbit is low relative to the probability that asteroids will. For these reasons, confirmed comet impacts on the earth are so far unknown. Therefore, if the Tunguska event was in fact caused by a comet, it would be a unique occurrence rather than an important case study of a known class of phenomena. On the other hand, if an asteroid did explode in the Siberian skies that June morning, why has no one yet found fragments?