Dinosaurs •

A Long-Lasting Volcanic Eruption Killed the Dinosaurs, New Study Shows

Dec 12, 2014 By Richard Carlisle 2 Comments

A new study conducted by Princeton and MIT researchers challenges the mainstream theory of dinosaur extinction. It seems that the asteroid impact was not the unique cause of the global die-off, but there was also a massive volcanic eruption in India that had its contribution.

The common theory that explains why dinosaurs were extinct suggests that about 66 billion years ago a mountain-sized asteroid impacted Earth and triggered dinosaur extinction. Scientists also believe that the crater on tip of the Yucatan Peninsula in Mexico marks the spot where the initial collision occurred. Also, impact debris was found scattered in hundreds of places across the planet.

However, there is also a small group of researchers that believe the die-off was the result, at least in part, of an unprecedented volcanic eruption in western India. These researchers say that the eruption was so great that it surpassed 1.3 million times the eruption of Mount St. Helens in 1980. The lava produced during the eruption created the Deccan Traps, a 200,000 square mile area covered by solidified lava shaped as step-like hills. The initial area covered by the lava flows in this area was estimated to half the size of modern India.

Earlier studies have dated the Deccan Trapps formation by using a margin of error of plus/minus 1 million years. The new study, published this week in Science, shows that the volcanic eruption that created the Deccan area occurred 250,000 years ago before the dinosaur die-off and lasted about 500,000 years. Scientists say the findings reveal that although the volcanic eruption was not the only cause for dinosaur extinction, it may be one of its leading causes.

Mr Blair Schoene, Princeton geosciences professor and lead author of the study, said that both asteroid impact and gradual volcanic activity in India could have led to the mass extinction.

“Both are potentially really important. I don’t know if we can say the extinction would have or would not have happened without both of them,”

Mr. Schoene said.

Princeton researchers say that the volcanic activity may have changed the climacteric conditions in such a way that after the asteroid collision dinosaurs went extinct.

However, other scientists are not so willing to abandon their old theory about how things really happened by admitting that a volcanic eruption killed the dinosaurs.

Dr Kirk Johnson, an expert on the mass extinction, said that the asteroid impact was a remarkable event that lined up exactly with the extinction while additional theories to explain it seemed to him useless.

David Fastovsky, geoscientist, said that the volcanic eruption theory was possible but pointless since the scientific community had enough evidence from the asteroid theory.

Fossil suggesting link between dinosaurs and ichthyosaurs found

Nov 6, 2014 By Richard Carlisle Leave a Comment

In what could serve as the lineage between dinosaurs and ichthyosaurs, scientists have uncovered a fossil record which is about 248 million years old in China that suggests a link between the two animals.

The discovery, named as Cartorhynchus lenticarpus, was made by the researchers at the University of California in 2011.

According to the scientists, the newly identified specimen serves as the missing link between the dolphin-like, aquatic-based ichthyosaur and its ancestors living on land.

Previously, there was no evidence of fossils to ascertain their transition from land to sea, until this latest discovery.

Talking about the new strong evidence, Ryosuke Motani, professor of planetary sciences at the University of California, said, “Now we have this fossil showing the transition. Unlike later ichthyosaurs completely adapted to a life at sea, it possessed unusually large and flexible flippers, like a modern-day seal, with flexible wrists that would have allowed it to crawl on the ground. There’s nothing that prevents it from coming onto land.”

Motani and his colleagues made the ancient discovery in China’s Anhui Province. According to the researchers, the fossil specimen is distinguished from its aquatic successors by the larger and more flexible flippers, similar to the one that allow seals to move about sand beaches and rock.

Later ichthyosaurs also possessed lengthy beak-like snouts, but the newly discovered amphibious fossil features a short nose, alike other terrestrial reptiles.

“By all means, this specimen is indeed very distinct from any ichthyosaur I have seen,” said paleontologist Valentin Fischer, from the Royal Belgian Institute of Natural Sciences who has not participated in the study.

The study was published in the journal Nature.

Fossil suggests fierce clash between aquatic Phytosaur and terrestrial Rauisuchids

Sep 29, 2014 By Christina Langfold Leave a Comment

A group of scientists has unearthed fossil of two types of predators, one living in aquatic habitat while another living on land, which suggests that both the Triassic predators may have fought with each other due to a reason best known to them.

About 210 million years ago, the top two predators, the Phytosaur (a large crocodilian dinosaur dominating the aquatic food chain) and the Rauisuchids (their land-based counterparts) may well have fought each other. But the scientists are clueless about why the two dinosaur species living in entirely different habitats would have had reason to come into any conflict.

The researchers at the University of Tennessee and the Virginia Tech said the fossil evidence suggested that the dominating phytosaur may well have hunted land creatures as well as ocean life.

Detailing about the fossils, the researchers said that they had recently found a phytosaur tooth which was embedded two inches inside the thigh bone of a rauisuchid. According to the researchers, the fossil showed the wound on the rauisuchid’s thigh had healed, suggesting the dinosaur had survived the attack. The rauisuchid’s thigh bone also had several kinds of bite marks suggesting that the attack was not an isolated phenomenon.

Researcher Stephanie Drumheller from the University of Tennessee said that the fossil evidence provides close insight to the type of relationship the two species may have had shared.

“Finding teeth embedded directly in fossil bone is very, very rare. This is for the first time any fossil has suggested about such violent behavior among phytosaurs,” Drumheller said.

The fossilized bone was discovered at the University of California Museum of Paleontology, Berkeley.

The study was detailed in the journal Naturwissenschaften.

Evolutionary gap between birds and dinosaurs closed by new study

Sep 27, 2014 By Anne-Marie Jackson 7 Comments

Science has known that there is some evolutionary link between dinosaurs and birds, but establishing a direct connection between the giant and today’s birds seems to be difficult. Now, as per a new study, an existing fossil record and several recent finds of feathered dinosaurs is used for drawing a direct connection.

Instead of direct transition in some kind of abrupt ‘missing link’ dinosaur/bird creature, that the paleontologists were not able to unearth in the fossils, the birdlike traits were slowly evolved by the dinosaurs as soon as the first dinosaurs themselves appeared. So finally, these science fueled nightmares of T-Rex suddenly sprouting wings and flying are put to rest.

850 body features of around 150 extinct species of bird were examined by Steve Brusatte, a paleontologist at Edinburgh University and his colleagues. A comparison of these against their dinosaur ancestors was made. With this, a complete family tree was created showing the evolution of features over time until the dinosaurs took flight finally.

It is still unknown as to why birds wound up so evolutionarily superior to dinosaurs that they lived on while the dinosaurs died out. The advantage of this new model is that it fits better with the existing evolutionary theory. Not only is this a gradual change, which is easier to explain through small changes over time than a big jump, but is also supportive of a theory that a paleontologist, George Gaylord Simpson put forth in the 1940s. The theory stated that once a new body plan first emerges, that is when the diversification of bird species is seen.

Meteorite Killed the Dinosaurs and Left Forests blooming

Sep 17, 2014 By Anne-Marie Jackson Leave a Comment

As per a report from the Arizona University, the impact of meteorite owing to which dinosaurs were doomed 66 million years ago razed the evergreens among flowering plants to a greater extent as compared to deciduous peers, as per a study led by the UA researchers.

The complete results of this research appear in the PLOS Biology Journal. With the application of biomechanical formulas to a hoard of thousands of fossilized leaves of angiosperms or flowering plants, apart from conifers, the ecology of a diverse plant community that thrived during a 2.2 million year period straddling the cataclysmic impact event was reconstructed by the UA team.

Researchers found indications like the fast growing deciduous angiosperms largely replacing their slow-growing evergreen peers. Examples of evergreen angiosperms like ivy and holly prefer shade, possess dark colored leaves and don’t grow very fast.

Benjamin Blonder, the lead author of the study said that “When you look at forests around the world today, you don’t see many forests dominated by evergreen flowering plants. Instead, they are dominated by deciduous species, plants that lose their leaves at some point during the year.”

Much needed evidence is provided by the study as to how this extinction event unfolded in the plant communities at that time. While it was understood that the species of plant that existed prior to the impact were different from those that came after, data was limited on whether the shift in assemblages of plant was a direct result of the event or was a random phenomenon.

Dinosaurs gradually shrank into agile flying birds over 50 mn years, says study

Aug 1, 2014 By Christina Langfold 1 Comment

A new study has revealed that the giant carnivorous dinosaurs gradually shrank over 50 million years to evolve into agile flying birds.

The discovery was made by the scientists from the University of Southampton.

The scientists derived the conclusion after studying a map of family tree of dinosaurs and their bird descendants.

Study co-author Darren Naish, a Vertebrate Palaeontologist in University of Southampton, said, “These bird ancestors also evolved new adaptations like wings, feathers, wishbones and four times faster than other dinosaurs.”

While studying the family tree, the researchers also showed that the branch of theropod dinosaurs, leading to the evolution of modern birds, was the only animal that kept getting inevitably smaller.

Lead author Michael Lee says, “Birds evolved through a unique phase of sustained miniaturisation in dinosaurs.”

Michael Lee is Associate Professor in School of Earth and Environmental Sciences and the South Australian Museum at the University of Adelaide.

“Being smaller and lighter in the land of giants, with rapidly evolving anatomical adaptations, provided these bird ancestors with new ecological opportunities like the ability to fly, glide and even climb trees,” Lee said while adding , “Finally, this evolutionary flexibility supported birds to survive in the deadly meteorite event that had tremendous impact on the dinosaurian extinction.”

For the study, the researchers reconstructed a family tree of dinosaurs. For this, they examined over 1,500 anatomical traits of the animal. They took help of sophisticated mathematical modelling to keep track of evolving adaption and the changing size of the body over the time and across dinosaur branches.

“The birds out-shrank from their dinosaurian ancestors, out-evolved and survived where their larger, less evolvable relatives could not,” said Lee.

The study researchers concluded that the branch of dinosaurs that led to evolution of birds was more evolutionary innovative than any other family of dinosaurs.

This evolutionary line was continued being experimented with different and often drastically smaller body sizes. But other dinosaur groups failed to reciprocate and ended up getting locked into narrow ecological niches. And this finally led to their extinction.

The study was published in the journal Science.

What led to extinction of Dinosaurs? Scientists say due to asteroids

Jul 31, 2014 By Christina Langfold Leave a Comment

Have you ever imagined what led to the extinction of Dinosaurs? Well, the scientists say it was just a bad luck.

According to a new study on extinction of dinosaurs, these animals were wiped out of the Earth following an asteroid event.

It was a vulnerable impact of an asteroid event which led to the extinction of the dinosaurs, the study said.

Dr Steve Brusatte, of Edinburgh University, carried the study.

According to Brusatte, due to the occurrence of the asteroid event the level of sea rose and initiate the volcanic activity, which in turn put many species more susceptible to extinction.

“It was a perfect storm of events that occurred when dinosaurs were at their most vulnerable,” Dr Brusatte said.

The scientists call it bad luck of the dinosaurs because they feel these animals might have survived if the asteroid event had hit the Earth’s surface a few million years later or earlier.

“Five million years earlier dinosaur ecosystems were much stronger, they were more diverse, the base of the food chain was more robust and it was harder to knock out a lot of species,” Dr Brusatte said.

As many as 11 leading dinosaur experts from the US, UK and Canada clubbed hands for studying the latest research on the dinosaurs, the asteroid impact and their extinction 66 million years ago.

Scientists say few evidences also suggested that some dinosaur species began dying off shortly before the asteroid hit the Earth.

What was baffling the scientists was a key question that whether this gradual declining numbers led to the extinction of dinosaurs even if the asteroid had not hit the Earth.

Following study, the researchers concluded that even if there was evidence of death of some species of plant eaters in North America in the said period, there was no proof of a long-term decline.

Most importantly, they believe that the soaring sea level and volatile volcanic activity claimed lives of many species leading to their extinction.

The study was published in the journal Biological Reviews.

Changyuraptor, the Flying Dinosaur, avoided crash landing by Feathers

Jul 16, 2014 By Richard Carlisle Leave a Comment

Changyuraptor

In the world of dinosaurs, raptors are reputed to be fast and ferocious and are known to have sharp claws for slash opening the prey. A new fossil was discovered in China and as per that, it was confirmed that not only can the face be ripped off by the raptors, but they are also capable of flying. This new species is termed Changyuraptor Yangi is known to be the largest flying dinosaur. It has long feathers which are known as chang yu in Chinese language and is named after that. The feathers grew on the legs and tail.

Dinos and changyuraptors from this family are known as 4-winged because the legs look like 2^nd pair of wings owing to long feathers. This study also proves that birds were not the ones responsible for origination of flight but it was dinosaurs who were responsible. The specimen that was studied had a length of 4 feet and weight of 9 pounds. This species have to face extra challenges during flight. Careful control is maintained during landings and this is very important for survival.

As per the analysis of researchers, it is stated that the long tail feathers are essential to catch winds which help them direct the flight during landings. This is similar to landing in a plan. The pace has to slow down and the nose has to be pitched up.

New Four-wing Dinosaur Species in China Flew like Airplane: Scientists

Jul 15, 2014 By Christina Langfold Leave a Comment

Scientists have unearthed a new fossil in China that provides strong clue about flying raptors that were 4 feet long from tail to tip.

According to the scientists, raptors are commonly known for being fast, brutal and their sharp claws but the new findings have proved that they could not only tear your face off but could also fly.

They say the fossils of the non-avian dinosaur not only appeared like a jet but it was an expert flier.

The new species of flying dinosaur which was found in Liaoning Province of northeastern China was named as Changyuraptor yangi. Scientists say the new dinosaur species was named after its long feathers. The word ‘Chang yu’ connotes ‘long feature’. The new dino species got its name from researcher Yang Yandong and the Chinese words that mean ‘long-feathered raptor’.

Their long feathers make their legs appear like a second pair of wings. This is because Changyuraptors and other dinosaurs from the same family are often known as “four-winged” dinosaurs.

Scientists also see the 125-million-year-old dinosaur as a strong evidence for establishing that flight preceded birds’ origin.

According to project leader Luis Chiappe, it is difficult as well as controversial to say whether an animal like Changyuraptor was able to take off from the land.

“We do know that they were very maneuverable animals and our study shows that they used their tail to slow down while they landed,” Chiappe said.

“At a foot in length, the amazing tail feathers of Changyuraptorare by far the longest of any feathered dinosaur,” Chiappe said.

Chiappe is a palaeontologist at the Natural History Museum of Los Angeles County.

The study was published in the latest issue of the journal Nature Communications.

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