There are some scientists who claim that the currently accepted theory according to which an asteroid or a comet caused the extinction of the dinosaurs is incorrect, and the reasons for their disappearance are purely evolutionary.
Professor David Penny from the University of Massey in New Zealand and Dr. Matt Phillips from the British University of Oxford claim in a new study published in "Trends in Ecology and Evolution" that contrary to popular belief, it was not a giant asteroid that killed the dinosaurs, but they were dying anyway.
Like a nuclear winter
The prevailing theory speaks of a collision of an asteroid or a comet with the Earth, which raised a huge amount of dust and sulfur into the air and blocked the sun's radiation. A second popular theory on the matter holds that the dinosaurs became extinct after a massive volcanic eruption raised large amounts of dust into the atmosphere and caused a result similar to a "nuclear winter". No theory can accurately explain the disappearance of the dinosaurs from the face of the earth, when mammals and other species of life managed to survive.
Penny and Phillips agree that there was a major geophysical event, but criticize the supporters of this theory, and claim that 25 years after its occurrence, no additional support has been received, apart from the fact that that "event" was the primary cause of the disappearance. According to them, the dinosaurs disappeared mainly because of evolutionary reasons.
high tide point
Penny points out that fossils can tell a lot about different species of dinosaurs, the ancient birds and mammals that lived on Earth, and this can indicate the time period in which the dinosaurs began to disappear, and in contrast birds and mammals began to multiply and become more diverse, but in the meantime the fossils could not shed light on reasons to disappear
"Meanwhile, the findings contradict the asteroid theory. The fossils and fossils tell a story of birds and mammals that began to reproduce, and on the other hand, of the dinosaurs that began to disappear at the end of the Cretaceous era." Penny summarized the issue: "The asteroid theory is a high point, but also a low point in 20th century science."
Huge egg layersThe dinosaurs were egg-laying reptiles that lived as the Mesozoic - the geological time unit that began about 250 million years ago - and became extinct about 65 million years ago, at the end of the Cretaceous era. Some of the dinosaurs were giant reptiles, such as the Brachiosaurus, the largest of the known dinosaurs, which lived in the Jurassic period, and reached a length of more than 30 meters and a height of about 12 meters. Other dinosaurs were small, less than 80 cm long - like an average chicken.
Although they disappeared from the world, the knowledge we have indicates that the conclusion that the dinosaurs were an evolutionary failure is far from the truth. Fossil remains of dinosaurs were discovered in different rock layers on all the continents of the earth, a fact that indicates their wide distribution, and the multitude of types adapted to different habitats. Also, the dinosaurs dominated their environment for 160 million years, and in contrast, the human species "Homo Sapiens" existed for only 100,000 years.
In addition, referring only to dinosaurs is misleading, because at the same time other large animals also became extinct, many plant species (until then fern trees dominated and they made way for leafy trees) and of course how the explanation that does not rely on an asteroid, can explain why mass extinctions also occurred in the sea at the same time the time.
