Dinosaurs are fascinating: some of them were the largest representatives of life on earth. So how could such forces of nature be exterminated?
First, it is important to remember that the dinosaurs have not all disappeared, since they still have representatives: birds.
Then, it should be specified that the dinosaurs were not the only victims of this cataclysm, but that the majority of living species did not support what scientists call “the Cretaceous-Tertiary crisis”, a vague mass extinction that occurred 65 million years ago. What’s the cause ? The theories have been clashing for years, some more outlandish than the other.
Scientists have always struggled to find a consensus explaining the extinction of the dinosaurs. Even if the most widely accepted theory is that of a meteorite, there are still gray areas today. Futura interviewed Éric Buffetaut, paleontologist, to shed some light on the matter. © Futura
Disappearance of the dinosaurs: the causes of the Cretaceous-Tertiary crisis
Despite everything, the researchers have proven scientific elements:
- A asteroid of 10 km would have fallen on Earth, in the Gulf of Mexico (Chicxulub crater, see the video above) about 300,000 years before the disappearance of the species. The dust formed successively to the shock would have covered the Earth for several months or several years.
- This period was marked by a very intense volcanism : the ashes could have covered the Earth for hundreds of thousands of years, depriving the plants of light and altering the food chain.
- Of the climatic changes have been raised and the sea level has receded markedly.
All these cumulative factors have profoundly changed the ecosystem and many species have failed to adapt, including most dinosaurs. The resulting chaos turned the history of life upside down: mammals were able to flourish and become, over time, the dominant group.
Mamenchisaurus paw The Mamenchisaurus lived between 145 and 150 million years ago during the Jurassic Tithonian Age. It was a herbivorous quadruped dinosaur with a very long neck. © Kabacchi, Flickr, CC by-sa 2.0
T-rex skeleton This T-rex skeleton can be seen at the Field Museum of Natural History, Chicago, USA. © Terence Faircloth, Flickr, CC by-nc-nd 2.0
Protoceratops, the “first horned head” Protoceratops lived in Mongolia during the Lower Cretaceous. Its name means “first horned head”. It was herbivorous and rather small, about the size of a sheep. © Kabacchi, Flickr, CC by-sa 2.0
Cryolophosaurus Skeleton Cryolophosaurus is a species of carnivorous dinosaur discovered in Antarctica in 1994. This dinosaur apparently belonged to the Theropods but this information causes controversy among scientists. Some prefer to classify it in the family Sinraptoridae. © Kabacchi, Flickr, CC by-sa 2.0
The Afrovenator, the most complete carnivorous dinosaur in Africa The Afrovenator was discovered in Africa in 1993. It is the most complete carnivorous dinosaur from this continent ever found to date. His name also means “African hunter”. The Afrovenator lived during the Cretaceous Period, between 132 to 121 million years ago. © Kabacchi, Flickr, CC by-sa 2.0
Spinosaurus, a theropod dinosaur Spinosaurus is a theropod dinosaur that lived from 110 to 97 million years ago. The only bones we have were destroyed during the Second World War during a bombardment on the city of Munich. Current knowledge is therefore based on the observations of the German paleontologist Ernst Stromer. © Kabacchi, Flickr, CC by-sa 2.0
A fossilized dinosaur bone This fossilized dinosaur bone is photographed here in macroscopic shot. © Genista, CC by-sa 2.0
Triceratops Skeleton The Triceratops, or triceratops, this dinosaur famous for its look and its peaks, was herbivorous. It belongs to the Ceratopsidae family and lived 65 to 68 million years ago in North America. He was the prey of the tyrannosaurus (the story does not say if it was the favorite prey). © Kabacchi, Flickr, CC by-sa 2.0
Edmontosaurus, this duck-billed dinosaur Edmontosaurus belongs to the family of Hadrosaurids (duck-billed dinosaurs). It was discovered in the Great Rockies in North America. He lived between 73 and 65.5 million years ago. He rubbed shoulders with the famous triceratops and T-rex. © Kabacchi, Flickr, CC by-sa 2.0
Allosaurus Skeleton This skeleton of Allosaurus (or allosaurus), a dinosaur from the Upper Jurassic era, is on display at the Comparative Anatomy and Paleontology Gallery of the Jardin des Plantes, in Paris. © Eric Gaba, Wikimedia Commons, CC by-sa 1.0
Imitation dino lamp in the shape of a dinosaur tail If you want to express your passion for dinosaurs, choose to dress your ceiling with an exquisite light suspension in the shape of a dinosaur tail! © Avlxyz, Flickr, CC by-sa 2.0
Tyrannosaurus rex skeleton This skeleton of T-rex, or Tyrannosaurus rex, is inspired by the attitudes and proportions of “The Truth About Killer Dinosaurs” (broadcast by the BBC). This dinosaur has nothing to envy to the T-rex Sue, exhibited at the Field Museum in Chicago, in the United States, nor to the one present at the National Museum of Natural History in Paris. © Johann “nojhan” Dréo, CC by-sa 3.0
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