Beginning of dinosaurs age:
As we know that dinosaurs lived on Earth for about 180 million years, After the top of the Cretaceous era (the last period of the Mesozoic, between the Jurassic and Tertiary period), the last dinosaur die about 66 million years ago, even the cause of their end is still a mystery, all are the reason for its end like climatic change, diseases, changing plant communities, and geologic events.
There was a mass extinction of the many animal species around the world, including the massive and diverse family of dinosaurs.
The challenge of explaining this huge loss of biological change has been the sector of geologists and palaeontologists. Their expertise in dating rocks and in reconstructing the characteristics of those long-gone life forms, from fossil bone and tooth pieces, maybe a remarkable achievement of scientific observation and analysis.
A giant meteorite, they reason, could have landed with an impact that kicked up enough dust and debris to dam out sunlight for an extended time — resulting in a deadly chain of events.
In the absence of the sun, all the plants died, without the plants, all the plant-eaters died; and without the plant-eaters, all the pieces of meat-eaters died. Sounds reasonable. But there is one problem with this theory: Paleontologists have not yet been able to find dinosaur skeletons in rocks dating to the period of impact. Some evidence even seems to indicate that all the dinosaurs had died before the meteorite hit.
As more clues have emerged, some seem to conflict, the who kills the dino’s?
Some theories landed like:
- A big meteorite comes from the outer space of the Earth and changing the climatic conditions and become hot atmosphere then the dinosaurs could not survive.
- Ash and gas generate from volcanoes in very big amounts and did not breathe many of the dinosaurs.
No one proves the reasons for die
Dinosaurs roamed the world for 160 million years until their sudden demise some 655 million years ago in an occasion now referred to as the Cretaceous-Tertiary extinction event.
Besides dinosaurs, many other species of mammal’s amphibians and plants died out at an equivalent time. Over the years paleontologists have proposed several theories for this extensive die-off.
One early theory was that tiny mammals ate dinosaur eggs thereby reducing the dinosaur population until it became unsustainable. Another theory was that dinosaurs’ bodies became too big to be operated by their small brains.
Some scientists believed an excellent plague decimated the dinosaur population then spread to the animals that feasted on their carcasses. Starvation was another possibility: Large dinosaurs required vast amounts of food and will have stripped bare all the vegetation in their habitat. But many of those theories are easily dismissed.
If dinosaurs’ brains were too small to be adaptive, they might not have flourished for 160 million years plants don’t have brains nor do they suffer from an equivalent disease as animals so their simultaneous extinction makes these theories less plausible. Did you know? The K-T extinction wasn’t the primary such massive die-off in history nor was it the most important The Permian-Triassic extinction event referred to as the good Dying occurred 2514 million years ago and eradicated 96 percent of all marine species and 70 percent of all terrestrial vertebrates’ species on earth.
For many years global climate change was the foremost credible explanation for the dinosaurs’ demise Dinosaurs thrived within the planet’s consistently humid.
How happened worldwide mass extinctions?
Around 75% of Earth’s animals, including dinosaurs, unexpectedly died out at the same point in time. So how was it all happened by a rock impact into the coast of Central America?
Paul explains, ‘The asteroid hit at high velocity and effectively all water vaporized. It made a huge crater, so in the immediate area, there was total destruction.
A huge blast wave and heatwave went out and it threw wide amounts of material up into the atmosphere. ‘It sent soot traveling all around the world. It didn’t completely block out the sun, but it reduced the amount of light that arrived at the Earth’s surface. So, it had an impact on plant growth.
Breeding seasons would have been shorter and conditions harsher. All living things would have been affected in some way, both on land and in the ocean.
‘There is a lot of discussion over the actual kill mechanism and how long that period lasted. There are still a lot of unknowns. But it was a massive event affecting all life on Earth, from microorganisms all the way through to dinosaurs,’
The casualty list is long. Among them, ammonites, some microscopic plankton, and large marine reptiles all died out.
But the loss made room for the beginnings of the modern world.
Worldwide whether change
The blame can’t absolutely rest on the asteroid. Prior to its crash landing, Earth was experiencing a period of climate change. This was making things harder for life on our planet.
In what is now central India, there was a substantial volcanic activity that, although unrelated to the asteroid impact, was causing problems of its own. The resulting lava outcrop is now known as the Deccan Traps.
For two million years there was a huge amount of volcanic activity going on, spewing gases into the atmosphere and having a major impact on global climate. ‘There were also longer-term changes.
The continents were drifting around and splitting apart from each other, creating bigger oceans, which changed ocean and atmosphere patterns around the world. This also had a strong effect on climate and vegetation.
Who’s survived after asteroid impact?
During the Cretaceous extinction event, plants were less affected than animals because their seeds and pollen can survive rigid periods for longer. After the dinosaurs’ extinction, flowering plants dominated Earth, continuing a process that had started in the Cretaceous, and continue to do so today. But all land animals weighing over 25 kilogrammes died out.
‘What we’re left with are basically the seeds of what we have today. Many of the major animal groups that are alive today were in place before the asteroid impact and they all suffered some level of extinction – but the lines that led to modern animals got through.
‘All of the non-bird dinosaurs died out, but dinosaurs survived as birds. Some types of bird did go extinct, but the lineages that led to modern birds survived.’
Initially the survivors were small, with birds the first to experience evolution to larger sizes.
There were a couple of sequences of pieces gigantic birds – predatory and herbivorous – but they weren’t around for very long and also went extinct.
Dinosaurs remain the largest land animals ever to have lived. The only animals that have ever exceeded their size are whales.
End of the Dinosaur
While most accounts specialize in the spectacular violence of this first jiffy to days after the impact it had been the long-term environmental effects that ultimately exhausted most dinosaurs and far of the remainder of life on Earth.
The prevailing dimness caused by the cloud meant photosynthesis would are dramatically reduced. The soot and ash would have taken months to scrub out of the atmosphere and when it did the rain would have fallen as acidic mud Massive fires would have produced huge amounts of poisons that temporarily destroyed the planet’s protective ozonosphere. Then there was the carbon footprint of the impact itself which released an estimated 10000 billion plenty of CO2, 100 billion plenty of carbon monoxide gas, and another 100 billion plenty of methane in one fell swoop consistent with geologist David Kring of the Lunar and Planetary Institute.
“The drilling program will help us understand how all this affected the post-impact climate—how much material was ejected into the stratosphere and what that material was’’