So Why Did Only Dinosaurs Become Extinct
Many theories have been put forward to explain why the dinosaurs became extinct while other types of animal survived.
Of course as weve seen it wasnt only the dinosaurs that went extinct. Many other types of animal also died out.
Whether an animal survived or not in the years that followed the asteroid strike may simply have been down to its size. Larger species need more to eat, and are therefore more susceptible to food shortages.
Smaller animals are also better able to seek shelter, either by burrowing or by hiding under rocks or plants. Large animals would find themselves much more exposed to adverse environmental conditions.
Dinosaurs may have been further disadvantaged by the large difference in size between young and adults. Infant dinosaurs have to be small to fit in an egg, even if theyll eventually grow to be a huge sauropod such as a Brachiosaurus. They have to do a lot of growing before theyre able to out-compete all of the other animals around them.
This would have been fine while food was plentiful. However, After the asteroid strike, resources would have been extremely scarce.
Mammalian young, on the other hand, are able to feed on their mothers milk immediately after being born. They also dont have to hatch from an egg, and are therefore closer to their adult size at birth.
Late Cretaceous mammals would have been able to out-compete dinosaurs as infants, and would therefore have been much more likely to reach adulthood.
What Killed The Dinosaurs
The end of the Cretaceous Period saw one of the most dramatic mass extinctions Earth has ever seen. Find out what brought about the end of the dinosaurs and many other animals too.
The fossil record shows that for the first 175 million years of their existence, dinosaurs took on a huge variety of forms as the environment changed and new species evolved that were suited to these new conditions. Dinosaurs that failed to adapt went extinct.
But then 66 million years ago, over a relatively short time, dinosaurs disappeared completely . Many other animals also died out, including pterosaurs, large marine reptiles, and ammonites.
Although the number of dinosaur species was already declining, this suggests a sudden catastrophic event sealed their fate – something that caused unfavourable changes to the environment to occur more quickly than dinosaurs and other creatures could adapt.
What Was The Youngest Dinosaur
TriceratopsBottom line: Yale scientists discovered aceratopsian likely a Triceratops close to a geological layer called the K-T boundary, providing evidence that dinosaurs did not gradually die out before a meteor impact 65 million years ago. Results of their study appear online July 13, 2011 in the journal Biology Letters.
Also Check: Dinosaur Games For 2 Year Olds
Asteroid Strike: The Alvarez Hypothesis
In 1980, the father and son scientists Luis and Walter Alvarez put forward a theory suggesting that the CretaceousPaleogene mass extinction was caused by an asteroid hitting Earth.
They calculated that an impact from an asteroid around 10 km in diameter would have caused an explosion millions of times bigger than that caused by a nuclear bomb.
The effect of such a blast would be wide-ranging and catastrophic. Anything in the vicinity of the blast would have been instantly vaporized. The huge dust cloud thrown up by the explosion would have darkened the skies and blocked out the sun.
Temperatures would have dropped, and plants would have been unable to grow in the darkness. This would have affected the entire food chain, from the smallest plants upwards. Any animal unable to adapt would have perished.
The Alvarez team came up with the asteroid impact theory after studying a narrow band of sediment that is found between rocks formed during the Cretaceous and Paleogene periods.
This band of rock is known as the CretaceousPaleogene boundary. The Alvarez team found that it contained an unusually high amount of iridium, a type of metal that is usually only found either in the Earths core or in asteroids.
The Alvarez Hypothesis suggests that the CretaceousPaleogene boundary was formed by debris thrown up by an asteroid strike, and that such a strike would have caused the extinction of the dinosaurs.
Sociological And Cultural Effects
An impact event is commonly seen as a scenario that would bring about the end of civilization. In 2000, Discover magazine published a list of 20 possible sudden doomsday scenarios with an impact event listed as the most likely to occur.
A joint Pew Research Center/Smithsonian survey from April 21 to 26, 2010 found that 31 percent of Americans believed that an asteroid will collide with Earth by 2050. A majority disagreed.
Recommended Reading: Where Can I See Dinosaur Footprints
New Clues Unearthed About Mammals Rapid Evolution After Dinosaur Extinction
Dr Steve Brusatte, a palaeontologist at the University of Edinburgh, UK, who previously studied the dinosaurs extinction, sought to understand exactly how this event affected mammals and their evolution.
I wanted to find out where mammals were living, what were their habits and how this exciting period of evolution set the stage for the great diversity of mammals that exists today, he said.
His work revealed that while many mammals were wiped out with the dinosaurs, there was also an increase in the diversity and abundance of those that did survive.
As part of the four-year BRUS project which ended in March, Dr Brusatte and his team collected new fossils dating back to the first million years after the extinction, which is thought to have lasted about 60,000 years, and put together a family tree of early mammals.
They hunted for fossils in New Mexico, US, which is known to have the best record of vertebrate specimens from this period. They collected several new fossils, including the previously unknown Kimbetopsalis simmonsae, a beaver-like species that lived during the first few hundred thousand years after the extinction.
The team also visited museums to explore fossil collections, which allowed them to describe the features of several important mammal species in detail, such as a type of Periptychus, one of the first mammals to prosper after the asteroid struck.
When Did The Dinosaurs Go Extinct
MasPix / Alamy
The end, when it came, came suddenly. An asteroid or comet 10 kilometres across slammed into the Gulf of Mexico, gouging a 180-kilometre crater and unleashing firestorms, eruptions and mega-tsunamis across the globe. The debris blocked out the Sun for years. The dinosaurs and the other 75 per cent of life that went down with them didnt stand a chance.
The story of the demise of the dinosaurs 65 million years ago is well known. But that of their origin is less so. Dinosaurs were the dominant animals on land for at least 135 million years, the longest reign of any group. Had the impact not happened, they might still be in control. Where did these magnificent beasts come from?
Where did dinosaurs come from?
For years, palaeontologists thought that dinosaurs rose rapidly to prominence about 200 million years ago by virtue of being evolutionarily superior to their competitors. The Triassic period in which they first evolved was seen as little more than a dress rehearsal for the true age of dinosaurs a kind of Jurassic-lite.
We now know this isnt how it happened. The secret of the dinosaurs success was luck: they were in the right place at the right time. And, like their demise, their origins and heyday were triggered by huge, catastrophic mass extinctions.
The Triassic period
The early birds
TriassicJurassic mass extinction
You May Like: The Last Day Of Dinosaurs
What Happened After The Chicxulub Asteroid Event
An example of the kind of catastrophic conditions that were created by these disasters is rock precipitation. Fossilized fish that were buried alive by the jumping sediment in their waterways in the earthquakes that followed the Chicxulub asteroid had small crystallized rock fragments in their gills. This shows that liquid rock shot into the atmosphere from the immediate impact crystallized and rained down from the sky effectively choking vast amounts of life with rock particles.
That alone is devastating but it was just a couple of the results of the asteroid impact. Long-term effects like vitamin D3 deficiency due to reduced sunlight could have weakened dinosaur shell eggs. This would have wiped out any attempts at reproduction by members of the dinosaur community that had managed to survive.
Pollutants in the atmosphere triggered severe winter conditions for long periods across the planet. This caused the mass dieoff of plankton and terrestrial plants that are the foundation of food chains. All food became scarce and animals starved.
What If Dinosaurs Were Still Alive
Most dinosaur species haven’t walked the Earth in about 65 million years, so the chances of finding DNA fragments that are robust enough to resurrect are slim. … After all, if dinosaurs were alive today, their immune systems would probably be ill-equipped to handle our modern panoply of bacteria, fungi and viruses.
Read Also: Dinosaurs Mentioned In The Bible
The End Of The Dinosaurs
To understand the extinction event that killed off the dinosaurs 65 million years ago, we first turn to the Tanis region of North Dakota.
Approximately 65 million years ago, the unfortunate fish in this estuary met an untimely end. Just 10 minutes after the Chicxulub asteroid hit the Yucatan peninsula, massive seismic waves buffeted the area, violently shaking the water. Unlike tsunamis, which are giant waves that come from a single point, the waves that hit the Tanis were like what happens to a swimming pool in an earthquake: the confined waters caused the waves to amplify. This caused the sediment at the bottom of the area to bury fish alive, as soon as one hour after the impact event.
Today, we see the results as pristinely preserved fish fossils some even with soft tissue intact.
The fossils of these fish contained something fascinating: small spherules of melted glass and rock within their gills. These spherules are believed to have come from the impact itself. After the asteroid hit the Earth, it sent a shower of molten rock into the atmosphere, which then crystallized at high altitudes. It rained back down on the Earth like deadly precipitation. The presence of the spherules within the fishs gills indicated that they were alive when the spherules penetrated their bodies.
During traveled to the Tanis region and collected specimens, which included the jawbones of paddlefish and the pectoral fin spines of sturgeons.
Impacts And The Earth
Major impact events have significantly shaped Earth’s history, having been implicated in the formation of the EarthMoon system, the evolutionary history of life, the origin of water on Earth, and several mass extinctions. Impact structures are the result of impact events on solid objects and, as the dominant landforms on many of the System’s solid objects, present the most solid evidence of prehistoric events. Notable impact events include the hypothesized Late Heavy Bombardment, which would have occurred early in the history of the EarthMoon system, and the confirmed Chicxulub impact 66 million years ago, believed to be the cause of the CretaceousPaleogene extinction event.
Read Also: Jurassic World: The Exhibition Coupon Code
Are Alligators And Crocodiles Dinosaurs
No, alligators and crocodiles are not dinosaurs. Crocodiles and alligators are archosaurs like the dinosaurs, but they are distinctly different. Modern birds are as related to crocodiles and alligators as the dinosaurs.
When the food chain was disrupted by the extinction event at the end of the Cretaceous, some cold-blooded animals were able to slow their metabolism and survive. Ancestral crocodiles were one of those animals.
Dinosaurs, as warm-blooded animals, constantly depended on the viability of the ecosystem in which they lived. This includes a stable flora and fauna population, which was devastated during the 5th mass extinction. As the entire ecosystem collapsed, so did dinosaurs too.
Crocodiles, on the other hand, were able to survive it.
How Long Did Dinosaurs Live Compared To Humans
As a result, it is estimated that they have been on Earth for much longer than they have been extinct. Dinosaurs appeared on Earth between 243 million and 231 million years ago. Dinosaurs were extremely successful, especially since the modern human population only existed for 200,000 years.
Dinosaurs lived on Earth between 165 and 177 million years ago. The Triassic period saw the first appearance of these creatures. Dinosaurs became extinct 66 million years ago. Birds became extinct during the Jurassic period, as a branch of dinosaurs evolved into them. epochs, while eras are divided into periods. Dinosaurs have been on the planet for between 165 and 77 million years. The dinosaurs became the dominant land animals in the Jurassic period around the same time. The dinosaurs, along with 75% of all species on Earth, lost their lives at the end of the Cretaceous period.
Read Also: Best Dinosaur Museums In The Us
How Did Dinosaurs Go Extinct
According to National Geographic, there are two main theories as to how the dinosaurs went extinct: interplanetary violence or problems on Earth.
In 1980, two scientists proposed the idea of a possible mountain-sized meteor slamming into earth, filling the Earth with dust, debris and gas that drastically altered the climate. According to National Geographic, scientists developed this idea due to high amounts of iridium in the K-Pg layer of the geological boundary zone where many fossils were found.
Iridium is considered relatively rare on Earth naturally and is more abundant in meteorites. The theory further developed after the discovery of a large impact crater near Mexicos Yucatán Peninsula. In 2016, scientists drilled into the crater and were able to conclude the impact that caused the crater was powerful enough to send deadly vaporized rock and gas into the atmosphere.
The other theory is massive amounts of lava flow from India, known as the Deccan Traps, occurred around the same 66 million years ago timeline. According to National Geographic, the eruption resulted in volcanic rock covering 200,000 square miles in layers that are up to 6,000 feet thick. Its believed this eruption could have been powerful enough to fill the air with dangerous amounts of carbon dioxide and other gasses, drastically altering the Earths climate.
Just curious: We’re here to answer life’s everyday questions
Can We Make Dinosaurs
Recent studies show DNA deteriorates and ultimately disintegrates after about 7 million years. … Dig up a fossil today, and any dino-DNA within would have long since fallen apart. That means, as far as scientists know, and even using the best technology available today, it’s not possible to make a dinosaur from its DNA.
Don’t Miss: Names And Pictures Of Dinosaurs
Fossils In Sedimentary Rocks Deposited During The Impact
Fossiliferous sedimentary rocks deposited during the KPg impact have been found in the Gulf of Mexico area, including tsunami wash deposits carrying remains of a mangrove-type ecosystem, evidence that after the impact water sloshed back and forth repeatedly in the Gulf of Mexico, and dead fish left in shallow water but not disturbed by scavengers.
Why Did The Dinosaurs Become Extinct
Evidence suggests an asteroid impact was the main culprit. Volcanic eruptions that caused large-scale climate change may also have been involved, together with more gradual changes to Earths climate that happened over millions of years.
When did dinosaurs go extinct and why?
The Cretaceous-Tertiary extinction event, or the K-T event, is the name given to the die-off of the dinosaurs and other species that took place some 65.5 million years ago. For many years, paleontologists believed this event was caused by climate and geological changes that interrupted the dinosaurs food supply.
Don’t Miss: Gluten Free Dinosaur Chicken Nuggets
How Do Scientists Know What Killed The Dinosaurs
Credit: Willgard Krause/Pixabay. AUSTIN, Texas Researchers believe they have closed the case of what killed the dinosaurs, definitively linking their extinction with an asteroid that slammed into Earth 66 million years ago by finding a key piece of evidence: asteroid dust inside the impact crater.
Why Did Dinosaurs Become Extinct: Deccan Traps Extinction Theory
The are huge volcanic rock formations that cover 500,000 square km . They now form the Deccan Plateau in west-central India.
The Deccan Traps were formed by volcanic eruptions around 66 million years ago. The eruptions may even have lasted for tens of thousands of years. The smoke, ash and gases cast up from the volcanoes would have darkened the skies and poisoned animals and plants. Temperatures would have dropped, plants would have been unable to grow, and food would have become scarce.
The Deccan Traps theory is credible, and may have been a factor in the extinction of the dinosaurs. However, today, most scientists think that the root cause of the extinction of the dinosaurs wasnt actually from Earth at all
Also Check: Dinosaur Books For Pre K
How Did Dinosaurs Become Extinct
Since we first found that dinosaurs had once been the dominant land animals on Earth, the next logical question was what happened to them?
Many theories have been put forward to explain the extinction of the dinosaurs. These range from the bizarre to rather more credible explanations including climate change, and poisonous volcanic gases.
Are There Any Dinosaurs Left
No, there are no true dinosaurs left on the planet. Crocodiles, alligators, and birds come close, but theyve evolved into animals that arent true dinosaurs.
If a huge cataclysm hadnt befallen the dinosaurs, they might have existed through today. They would have been capable of living in some areas of our modern world, despite it being colder now than it was then.
However, if dinosaurs hadnt gone extinct, would mammals have had the chance to develop enough to create primates and hominids? Most likely not, as entire ecosystems would have developed differently because of dinosaurs grazing or predatory behavior.
In that sense, we should be thankful that no true dinosaurs still exist.
Recommended Reading: Authentic Dinosaur Fossils For Sale