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Results tagged “dinosaurs” from NatGeo News Watch

A fly that buzzed around during the time of dinosaurs is being described as a new family, genus and species of fly never before observed.

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This artist's rendering of a 100-million-year old insect shows the unusual horn on its head topped by three eyes.

Image by George Poinar/Courtesy OSU

"A single, incredibly well-preserved specimen of the tiny but scary-looking fly was preserved for eternity in Burmese amber, and it had a small horn emerging from the top of its head, topped by three eyes that would have given it the ability to see predators coming," Oregon State University said in a statement about the discovery.

"No other insect ever discovered has a horn like that, and there's no animal at all with a horn that has eyes on top," said George Poinar, Jr., a professor of zoology at OSU, who announced the new species in the journal Cretaceous Research.

"It was probably a docile little creature that fed on the pollen and nectar of tiny tropical flowers," Poinar said. "But it was really bizarre looking. One of the reviewers of the study called it a monster, and I have to admit it had a face only another fly could have loved. I was thinking of making some masks based on it for Halloween."

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This ancient "unicorn" fly that lived 100 million years ago in Burma has a "horn" in the center of its forehead, capped with three small eyes.

Photo by George Poinar/Courtesy OSU

The fly lived in the jungles of Myanmar and was found trapped in amber that was from 97 to 110 million years old, OSU said. "The gooey, viscous tree sap that flowed down over the fly and later turned to stone preserved its features in lifelike detail, including its strange horn topped by three functional eyes."

Strange evolutionary adaptations

"If we had seen nothing but the wings of this insect, it would have looked similar to some other flies in the family Bibionomorpha," Poinar said. "But this was near the end of the Early Cretacous when a lot of strange evolutionary adaptations were going on. Its specialized horn and eyes must have given this insect an advantage on very tiny flowers, but didn't serve as well when larger flowers evolved. So it went extinct."

Poinar named the new fly Cascoplecia insolitis--from the Latin "cascus" for old and "insolates" for strange and unusual.

The fly also had other very unusual characteristics, the study found, such as an odd-shaped antenna, unusually long legs that would have helped it crawl over flowers and extremely small vestigial mandibles that would have limited it to nibbling on very tiny particles of food.

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This image of an ancient fly in amber more closely shows the strange horn on its head, topped by three eyes.

Photo by George Poinar/Courtesy OSU

Pollen grains found on the legs of the fly suggest that it primarily must have fed on flowers.

"This fly lived during the time of the dinosaurs, but also in a period when Triassic and Jurassic species were becoming extinct, modern groups were appearing and angiosperms, or flowering plants, were diversifying. Some of the characteristics of the fly were common to other families found around that time, but others were extremely different--especially the horn with eyes on top," OSU said.

The specimen found in amber was well-preserved, lacking only the rear left portion of the abdomen and a portion of the left hind leg. It's rare to find specimens with essentially a complete body as well as wings, scientists noted in the report.

The fossil came from an amber mine in the Hukawng Valley of Myanmar, first excavated in 2001.

"This 'unicorn' fly was one of the oddities of the Cretaceous world and was obviously an evolutionary dead end."

Poinar is an expert on insects and other life forms that have been preserved in amber, and has used them as clues to create detailed portraits of ancient ecosystems.

"None of the specialized body characters of Cascoplecia occurs on previously reported Cretaceous bibionids," the report concluded. "This 'unicorn' fly was one of the oddities of the Cretaceous world and was obviously an evolutionary dead end."

By James G. Robertson, National Geographic Digital Media

Large algae blooms could have been a major contributing factor to the last five mass extinctions and smaller die-offs throughout history, researchers at Clemson University announced yesterday, challenging the theories that a major cataclysmic event, like an asteroid strike, alone caused the extinctions.

Today, a change in sediment or water temperature can cause large algae blooms, which can remove oxygen from the water and create toxins that suffocate fish and poison other organisms. The toxins created by some types of algae can creep into groundwater and poison plants, too, which causes problems up the food chain.

The researchers found evidence of spikes in fossilized algae, called stromatolites, about the same time the mass extinctions occurred, leading them to believe that algae had a role in disrupting the food chain by killing off fish or poisoning herbivorous creatures. The blooms could have been caused by fallout from volcanoes or asteroid collisions, or simply from climate change.

While it is a theory about the past, the theory could have an impact on the future as well.

"This hypothesis gives us cause for concern and underscores the importance of careful and strategic monitoring as we move into an era of global climate change," wrote James W. Castle and John H. Rodgers, the authors of the study that was presented at the 2009 meeting of the Geological Society of America.

There is evidence that toxic algae has been creeping northward due to climate change, says Castle, potentially causing problems for wildlife and humans as the planet gets warmer.

You can read more about developments in the asteroid extinction theory at National Geographic News.


 

 

 

The city-size rock that impacted Earth sixty-five million years ago, in what is now Mexico's Yucatán Peninsula at a site known as Chicxulub, may not have been the main cause of the great extinction event that wiped out the dinosaurs and as much as 80 percent of the rest of life on the planet.

Instead, a 25-mile-wide meteorite, as much as five times the size of the one that struck Chicxulub, could have slammed into Earth where India is today, vaporizing the planet's crust and leaving the largest multi-ringed crater the world has ever seen.

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Impact illustration courtesy NASA

Texas Tech University scientists think they have pieced together the geological evidence for this impact, and they will present their theory to the annual general meeting of the Geological Society of America (GSA), in Portland, oregon, this coming weekend.

"A mysterious basin off the coast of India could be the largest, multi-ringed impact crater the world has ever seen. And if a new study is right, it may have been responsible for killing the dinosaurs off 65 million years ago," GSA said in a statement about the research, released today.

"Sankar Chatterjee of Texas Tech University and a team of researchers took a close look at the massive Shiva basin, a submerged depression west of India that is intensely mined for its oil and gas resources. Some complex craters are among the most productive hydrocarbon sites on the planet," GSA said.

Chatterjee will present the research at the GSA meeting on Sunday.

Largest crater on the planet

"If we are right, this is the largest crater known on our planet," Chatterjee said. "A bolide of this size, perhaps 40 kilometers (25 miles) in diameter, creates its own tectonics."

By contrast, the object that struck the Yucatan Peninsula, and is commonly thought to have killed the dinosaurs, was between 5 and 6 miles wide, GSA said.

"It's hard to imagine such a cataclysm. But if the team is right, the Shiva impact vaporized Earth's crust at the point of collision, leaving nothing but ultra-hot mantle material to well up in its place.

"It is likely that the impact enhanced the nearby Deccan Traps volcanic eruptions that covered much of western India. What's more, the impact broke the Seychelles islands off of the Indian tectonic plate, and sent them drifting toward Africa."

Dramatic geological evidence

The geological evidence is dramatic, GSA added.

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Three-dimensional reconstruction of the submerged Shiva crater, western shelf of India, from different cross-sectional and geophysical data. The overlying 4.3-mile-thick Cenozoic strata and water column were removed to show the structure of the crater.

Image courtesy of Geological Society Of America

"Shiva's outer rim forms a rough, faulted ring some 500 kilometers [310 miles] in diameter, encircling the central peak, known as the Bombay High, which would be 3 miles tall from the ocean floor (about the height of Mount McKinley).

"Most of the crater lies submerged on India's continental shelf, but where it does come ashore it is marked by tall cliffs, active faults and hot springs. The impact appears to have sheared or destroyed much of the 30-mile-thick granite layer in the western coast of India."

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Illustration courtesy of NASA

Two large impacts such as Shiva and Chicxulub in quick succession, in concert with Deccan eruptions (a series of monumental volcanic eruptions in India that some scientists believe may have been the real culprit that killed the dinosaurs 65 million years ago), would have devastating effects globally, Chatterjee and colleagues say in the abstract to their presentation.

That, in turn, could have caused the "climatic and environmental catastrophes that wiped out dinosaurs and many other organisms" at the time of the mass extinction.

The team hopes to go India later this year to examine rocks drill from the center of the putative crater for clues that would prove the strange basin was formed by a gigantic impact.

"Rocks from the bottom of the crater will tell us the telltale sign of the impact event from shattered and melted target rocks. And we want to see if there are breccias, shocked quartz, and an iridium anomaly," Chatterjee said. "Asteroids are rich in iridium, and such anomalies are thought of as the fingerprint of an impact."

Related National Geographic News stories:

Yucatan Asteroid Didn't Kill Dinosaurs, Study Says
A controversial new study contends that a second, as yet unidentified asteroid impact must have caused the mass extinction popularly attributed to the Chicxulub asteroid.

"Dinosaur Killer" Asteroid Only One Part of New Quadruple-Whammy Theory
The dinosaurs were killed not by a lone asteroid strike but by the quadruple whammy of global climate change, massive volcanism, and not one but two gigantic collisions.

Asteroid Rained Glass Over Entire Earth, Scientists Say
Scientists studying the fallout from a huge asteroid that crashed into Earth 65 million years ago have gained better understanding of the event that most likely took out the dinosaurs and much other life on the planet.

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Photo copyright Project Exploration, all rights reserved

Among the thousands of students participating in the Indiana Dunes BioBlitz was a small group from Project Exploration.

Founded in 1999 by paleontologist Paul Sereno and educator Gabrielle Lyon to make science accessible, Chicago-based Project Exploration inspires minority youth and girls with the wonders of science and discovery.

"We get students interested in science, keep students interested in science and equip students to pursue science," says the Project Exploration Web site. "Our programs target Chicago public school students who have been low and middle achievers, but who are also curious, open-minded, and passionate; 85 percent of our students are from low-income families. Project Exploration sets students on a path to future careers in science."

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The Project Exploration team at the Indiana Dunes BioBlitz on Saturday, from left: Mikki Brown, Project Exploration, Youth Programs Coordinator; Nina C., Curie High School; Jehad B., Curie High School; Michael R., ACE Tech Charter School; Gabrielle Lyon, Project Exploration Cofounder and Executive Director; Khadijah P., North Lawndale College Prep. (Not pictured, Mary Elizabeth Perez, Project Exploration)

Photo by David Braun

I met up with the Project Exploration team at the bioblitz today and heard about their adventure in the wet woods, where there they accompanied herpetologist Alan Resetar from Chicago's Field Museum (in the top photo) in search of species of reptiles and amphibians.

The highlight of the outing, the students agreed, was a sighting of a large snapping turtle.Read more about this on the Project Exploration Blog.

The bioblitz is what Project Exploration is all about, said Gabrielle Lyon, Project Exploration cofounder and executive director. "It's about bringing students and people with curious minds together with scientists to explore the world."

Exploring the Indiana Dunes also helped the students understand the environment preferred by reptiles, Lyon explained. This summer the students will participate in a fossil dig, and there they would use the knowledge of modern reptile habitat to help piece together the ancient environment in which reptiles lived during the dinosaur age 67 million years ago in Montana.

Watch this video in which Gabrielle Lyon and students talk about Project Exploration and the bioblitz:


Video by David Braun

Read more on Project Exploration's Blog >>

 

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3-D computer rendering courtesy Pipestone Creek Dinosaur Project

Fossils of an entire herd of dinosaurs that died in a flood or some other catastrophe 73 million years ago in what today is Alberta, Canada, have been named after the science teacher that found them.

Pachyrhinosaurus lakustai is the name of the new species, Philip Currie, a University of Alberta paleontologist involved in the excavation of the fossils in the late 1980s, announced today.

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Illustration by Nick Longrich/Courtesy University of Calgary

A bizarre, chicken-size dinosaur that had tweezer-like jaws and stumpy but powerful forearms has been found in Alberta, Canada. It is the smallest dinosaur species ever found in North America. Researchers believe it may have preyed on insects.

It looked "like an animal created by Dr. Seuss," said Nick Longrich, a paleontology research associate in the department of biological sciences at the University of Calgary.

The remains of the Cretaceous "anteater" were found during a dig for Albertosaurus fossils in 2002.

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