Around 200 million years ago, dinosaurs dominated the planet, outcompeting and overwhelming their reptile ancestors from the Triassic period. The evolution of dinosaurs has long remained a mystery, but new research explains their successful dominance. The paleontologist and lead author of a study on the rise of dinosaurs published on November 27Martin Qvarnström, expose: “We know a lot about the life and extinction of dinosaurs, but very little about how they came to dominate reptiles.”
To better understand these extinct giants, Martin Qvarnström and his team studied for ten years fossils called “bromalites”, which are actually remains of the digestive system: vomit and dinosaur droppings. These wonders were collected in a region of southern Poland, and date back to a period from the end of the Triassic to the beginning of the Jurassic, i.e. from approximately 247 million years to 200 million years BC . A CNN article tells us more about how researchers unlocked the secret of dino droppings.
The researchers found that over time, fossilized feces and vomit increased in size and variety, indicating the emergence of larger creatures with different diets. After extensive research using cutting-edge equipment, such as the European Synchrotron Radiation Facility in Grenoble (France) which produces X-rays 10,000 billion times brighter than the X-rays used in hospitals, the researchers were able to propose an explanation for the rise of the dinosaurs.
Bigger and more plant-loving
Triassic reptiles were omnivorous. They then evolved into the first dinosaurs, carnivores and herbivores. A turning point was taken when the increase in volcanic activity at the end of the Triassic led to a diversification of nourishing plants, followed by the emergence of large herbivorous dinosaurs, such as Diplodocus or Supersaurus. Then, 200 million years ago, giant carnivorous dinosaurs appeared, like the Cryolophosaurus or the Dilophosaurus (the posthumous celebrities of the big screen). The reign of dinosaurs continued until an asteroid struck Earth off the coast of what is now Mexico 66 million years ago.
Before Martin Qvarnström’s publication, two theories existed to explain the transition from a world dominated by non-dinosaurian reptiles to a world filled with dinosaurs. The first suggested that dinosaurs evolved to physically outperform their reptile rivals. The second evoked a better adaptation to climate changes at the end of the Triassic, compared to reptiles which became extinct at the same time. Ultimately, Martin Qvarnström’s research using Polish fossils appears to combine the two theories. Dinosaurs would have been better able to physically cope with how environmental changes altered the food available.
They also appeared to feed on a wide range of plants. The droppings of the first large herbivorous dinosaurs, the Sauropodomorphs, contained large quantities of tree ferns, but also many other types of plants and charcoal. Moreover, the team thinks that the charcoal helped digest the ferns, which can be toxic. Despite all their efforts to adapt and survive, from their size to their diet, it only took a large stone to exterminate the dinosaurs.
Source: www.slate.fr
