Monday, January 16, 2017

Darkness and coldness - killed the dinosaurs

Artist depiction on the impact of the asteroid 

Sixty six years ago, the extinction of the dinosaurs gives the evolution of the mammals, which results to the human being on earth. The scientist discovered because of the impact of the asteroid, the droplets of sulfuric acid formed in the atmosphere as clouds. These clouds blocked the sunlight for several years. Due to this the plants died and the death spreads through the food web. The previous theories were based on the dust evolved by the impact. But the new theory show that the sulfuric droplets resulted in long-lasting cooling which brings the end to the dinosaurs.

"The big chill following the impact of the asteroid that formed the Chicxulub crater in Mexico is a turning point in Earth history," says Julia Brugger from the Potsdam Institute for Climate Impact Research (PIK). She is the lead author of the study to be published in the Geophysical Research Letters. She also says "We can now contribute new insights for understanding the much debated ultimate cause for the demise of the dinosaur at the end of the Cretaceous era." To prove this theory the scientists used a special computer process using a climate model on the atmosphere, ocean and the sea ice. The researchers did research proving that the sulfur vaporized from the asteroid is the main reason for blocking the sunlight and cooling down the earth.    

In the tropical region, the annual mean temperature reduces from 27 - 5 degree Celsius. "It became cold, I mean, really cold," says Brugger. The temperature of the global annual mean surface drops down by at least 26 degrees Celsius. The dinosaurs used to live in flourishing climate. After the asteroids impact the average annual temperature was below the freezing point for above 3 years. Because of this the ice caps expanded. Even on the tropical region the temperature eventually went down from 27 degree to hardly 5 degree Celsius. "The long-term cooling caused by the sulfate aerosols was much more important for the mass extinction than the dust that stays in the atmosphere for only relatively short time. It was also more important than local events like the extreme heat close to the impact, wildfires or tsunamis," says the co-author Georg Feulner who who leads the research team at PIK. The scientists also discovered that it took 30 years for the climate to recover. 

Through the study of the earths past the scientist can predict the future threats by asteroids to the earth. "It is fascinating to see how evolution is partly driven by an accident like an asteroid's impact -- mass extinctions show that life on earth is vulnerable," said Feulner. "It also shows how important the climate is for all species on our planet. Now-a-days the most immediate threat is not from natural cooling but from human-made global warming" 


Wednesday, January 11, 2017

New giant on town: Titanosaur exhibits at the American Museum of Natural History

Titanosaur at the American Museum of Natural History

Not only T.rex and Barosaurus, there is a new pre-historic giant is in town. And it will be displayed at the American Museum of Natural History. They call this creature Titanosaur and the show starts from this Friday. It is the biggest dinosaur ever to be displayed at the museum. It is one among the largest dinosaur discovered. This dinosaur is of 122 feet long and rise till a height of 20 feet almost to the ceiling. It weights approximately 70 tons, almost the weight of 10 African elephants.

The cast model skeleton of Titanosaur is made of plaster-of-paris and with some well preserved bones which was discovered recently. It includes the huge 8 foot long thigh bone. The plaster cast bones were created using the new technology like scanning and 3-D printing. Diego Pol  is one of the paleontologist who discovered and dug out the previous unknown dinosaur discovered in Argentina in 2014. He also has a main part in this process. 

Installation of Titanosaur at the American Museum of Natural History

The term Titanosaur refers to a group of dinosaur with similar type and size. It is according to Don Phillips president of the New York paleontology society and a lecturer at New York University. "There are your classic long-necked, long-tailed, really big dinosaurs," said Phillips. "They are the largest land animals that ever lived". The scientist believe that it is a herbivore. On knowing this Phillips said "They were probably not much of a threat if you lived back then," and he added, "Unless you got stepped on by one."

The dinosaur is installed in a walking pose with the neck more horizontal than vertical. It is the only possible way to install. If the neck is in vertical position it wouldn't fit inside the museum. In addition to that the head and neck of the Titanosaur is poked out of the fourth-floor hall towards the elevators. This provides the visitors an interesting introduction.  

Tuesday, January 10, 2017

Can dinosaur Come back to life?

The last Bucardo - a particular species of a wild goat was vanished on Jan. 6,2000. This wild mountain goat was named as Celia was crushed to death by a falling tree on the cliffs of  the Spanish Pyrenees which turns her to history. Because she is the last one of her kind. 

A Group of Spanish scientist had an idea of bring the species Celia back to life. Ten months earlier they took the sample of her with the hope to de-extinct the species.Two years later the DNA taken from Celia's tissue is injected into goat eggs that had been stripped of with their own genetic material. After some powerful electrical jolt, the cells starts to multiply. The embryos were embedded into the womb of substitute mother goats and most of the pregnancies failed except one.

Finally history was created on July 30,2003 one of the Celia's clone was born. Making place in the history that for the first time ever a species comes back from extinction. Unfortunately she could last only for 7 minutes. She a bad health and her lungs were not formed properly. It is only species till now had gone extinction twice till now. 

Using the same concept scientist believe that they can de-extinct the dinosaurs. The most important source needed for it is a dinosaurs DNA but all we have is the remaining portion of the dinosaur in the form of stone fossils.     

In 1990's many discoveries claimed to have retrieved DNA from a 80 million-year-old dinosaur bone but those were fake claims. It was proved by the Noble prize winning  Tomas Lindahl who is biochemist. It is because of the way DNA breaks down. He proves that it cannot survive such a long time frame. In 2012 his claim was proved by a study that half-life of DNA is just 521 years. So after 6.8 million years every single link of the DNA will be dead. It is impossible to retrieve DNA from such old fossils.

The scientist haven't lost their hopes. Still they are searching for the DNA because they believe that they can bring these extinct creatures back to life.

Monday, January 9, 2017

Dinosaurs tracks shows that they might have hunted in packs

Round footprint of some vegetarian dinosaur probably Zuniceratops

Paleontologist found the footsteps of three carnivorous dinosaur which are of different sizes in the White Mountains. They also discovered the tracks of some other vegetarian dinosaurs around those places. Because of these clues, the scientists predict they hunt in pack to eat. On examining the tracks the scientist thinks these tracks belong to a group of Tyrannosaurs.

Scientist discovered other fossils and tracks to suggest that the dinosaurs hunt in packs, but the evidence they have is not enough to prove this behavior. Because it is about the things that humans can never go back in time and see. Dino tracks are the most important evidence which helps to know about its type.

The footprints of the first carnivorous reptiles were first discovered in rocky corner in New Mexico by the land-management bureau. The scientist discovered 13 footprints of three flesh eating dinosaurs of sizes: small, medium and large. The size, shape and depth of the three footprints directs to Tyrannosaurs. These tracks where discovered parallel to each other and goes in a straight line which indicates that the dinosaurs move in a group.

Another round footprint was discovered from the same place. The scientist predict that it can a vegetarian horned dinosaur of Triceratops family. The suggestion is Zuniceratops, the dinosaur with small horns. Because of this incident to scientist things that they hunt as packs but it can only be a possibility because herbivorous dinosaurs are also not loners.

At one Canadian site, the paleontologist discovered a collection of fossils of Tyrannosaurs of different age group. These reptiles died together as a family. Because of this the scientist suggests that the dinosaurs stick together. With all these evidences and footprints the scientists suggests that they stay in packs. But they are researching further more to prove it.  


Thursday, January 5, 2017

Dippy the Diplodocus leaves London

Dippy the Diplodocus - Natural History Museum in London

Yesterday was the last day of Dippy in the Natural History Museum in London. Since 1905 it was dominating the entrance of the museum. The Diplodocus was presented by a Scottish-born American industrialist Andrew Carnegie to the museum.

Dippy is a skeleton of 292 pieces of bones made of plaster-of-paris. It is dark grayish brown in color. It stands in a height of 22 feet and 84 feet in length. The Diplodocus was discovered in 1878 by professor Othniel C Marsh at Yale University. The name Diplodocus derived from Greek - diplos(double) and dokos(beam), it refers to the formation of bones at the bottom of its tail.  These giant dinosaurs lived between 156 and 145 million years ago. 

A team is working on the process of dismantling the Dippy and the conservators will prepare for 12 months on the soft plaster-of-paris for the journey. The show will be on 8 locations around Britain from 2018 up to 2020. This tour is organised for the common people to know about the importance of museum. It will be displayed at: Dorset County Museum, Birmingham Museum and Art Gallery, Ulster Museum, Kelvingrove Art Gallery and Museum, Glasgow Great North Museum, Hancock, Newcastle upon Tyne, National Assembly for Wales, Number One Riverside, and Rochdale Norwich Cathedral.

In the place of Dippy, a real skeleton of blue female whale will be placed. The 83 feet whale is of 4.4 tonne weight. It was already there inside the museum and now it will be moved to the entrance. 

At the end of 2020, Dippy will be displayed outside the museum in form of bronze cast.


Wednesday, January 4, 2017

New discovery on the time taken by a baby dinosaur to hatch

Embryo of Protoceratops discovered from Mongolia
The research done by the professors from the University of Calgary discovered that a baby dinosaur will take three to six months to hatch their egg. The times depends on the size of the dinosaur. The professor Gregory Erickson of Florida State University and a team of scientists discovered answers for riddles where the paleontologist have have been trying for years.

It was published in an article, the Proceedings of the National Academy of Sciences states the complications of the prehistoric creatures are solved and the embryonic dental records helps to know long the baby dinosaur will take to hatch the egg. All these time paleontologist were comparing the hatching of dinosaur to other animals and modern birds which survived the extinction at the end of cretaceous period.

The incubation of the baby dinosaur is discovered by researchers by observing the embryo fossils of Protoceratops found in the Mongolian Gobi Desert and Hypacrosaurus found in Alberta. All this time the scientist conjectured that the hatching of baby dinosaur is similar to birds. The eggs of birds takes 11 - 85 days, but comparing to these massive reptile eggs which takes weeks - many months to hatch. Because comparing the birds egg, dinosaurs egg are large which weights more than 4 kilograms or the size of football.

Embryo of Hypacrosaurus observed by researchers

The paleontologist Darla Zelenitsky at the University of Calgary states that the team has observed sharply the daily growth lines of the baby dinosaurs teeth. By using the number of growth lines and by doing some calculations the researchers can able to the count the number of days taken by a baby dinosaur to hatch. With the help of those growth lines they discovered that the 194 grams embryo of Protoceratops takes almost three months to hatch and it takes six months for the embryo of Hypacrosaurus which weights more than 4 kilograms. 

For a long time the hatching period of embryos were compared to modern birds due to this observations the scientist revealed all the characteristics of dinosaurs are not like birds. The previous researches were done based on the egg mass and comparing the egg mass directly to the birds. By researching on the teeth the scientist found the hatching period is closer to the reptiles.

This research was based on two species, in future the research will be continued on many other embryos of dinosaur said by Zelenitsky.