If the explosive fireball doesn't get it, the drop in global temperature on a planet with little or no ice - due to a blanket of heat-shielding debris in the atmosphere - has occurred.
Paris:
Most people know that dinosaurs that live on Earth were wiped out about 66 million years ago when an asteroid collided with Earth about twice the diameter of Paris.
If the explosive fireball doesn't get it, the drop in global temperature on a planet with little or no ice - due to a blanket of heat-shielding debris in the atmosphere - has occurred.
What most people don't know is that more than 100 million years ago, another climate change catastrophe destroyed a different set of dinosaur species, with many of them extinct.
Except this time, it was caused by global warming, not global cooling, with the planet warming more rapidly than the dinosaurs could adapt.
Scientists found evidence of this traumatic event about 179 million years ago in plant fossils in Argentine Patagonia.
They also discovered a previously unknown dinosaur.
This species, called Bagualia alba, belongs to the large family of long-necked sauropods, and is the largest of the animals to walk on Earth.
Before the greenhouse event, sauropods were only one subspecies of the Surobodomorpha.
A study published Wednesday in the Royal Society showed that other dinosaurs in the same group were smaller and lightweight, and some were no larger than goats.
But a series of volcanic eruptions over several million years released massive amounts of carbon dioxide and methane into the atmosphere, warming the planet and transforming the vegetation of the dinosaurs.
The climate shifted from mild, warm and humid with variegated leafy vegetation to a very hot and dry seasonal regime.
Smaller dinosaurs than Sauropodomorpha weren't able to handle change, but larger dinosaurs - such as Bagualia alba - thrived.
Paleontologist and lead author Diego Ball told AFP that "sauropods are huge, four-legged animals with long necks," which means they can reach the tops of trees.
"Its extremely strong lower jaw and spoon-shaped teeth have been adapted to feed on all kinds of plants such as coniferous trees."
Conifers in the early Jurassic period had hard, leathery leaves that would pose a challenge to any herbivore.
Paul, head of science at the Egidio Feroglio Museum of Paleontology in Patagonia, said it gave B. Alba has an advantage over other sauropodomorpha dinosaurs.
The new sauropod's diet saw them expand in size from 10 meters to 40 meters in length, as large digestion chambers were required to handle.
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