Source by: Live Science
Dinosaurs are a group of prehistoric reptiles that dominated the planet earth before getting extinct about 65 million years ago. While research exploring the main causes of the dino apocalypse still continues, paleontologists believe geographical and climatic changes, natural disasters, and diseases largely contributed to these predators’ extinction.
To dig deeper into the events that lead to the dino apocalypse, this article explains 10 key factors that played a key role in the extinction of dinosaurs according to researchers and paleontologists. Let’s find out!
Factors that Contributed to the Extinction of Dinosaurs
1. Supernova
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In 1956, Soviet astronomer and astrophysicist Joseph Shklovsky linked the extinction of dinosaurs to cosmic rays coming from supernova explosions. While determining what caused the extinction of dinosaurs and life on earth, Shklovsky theorized that a supernova could have released a huge amount of radiation killing all the dinosaurs.
Source by: Universe Today
Shklovsky’s supernova theory was supported by paleontologist Dale Russell and physicist Wallace Tucker in 1971. The duo also said X-rays and several other radiations had bombarded the earth’s upper atmosphere with the explosion of a neighboring star. As a result, temperatures plummeted sharply that altered the climate and destroyed biodiversity.
Like Shklovsky, Tucker and Russell also could not provide any direct evidence to back their theory. Hence, scientists started working on the asteroid impact hypothesis and several other theories to find a logical explanation of their questions.
2. The Meteor Impact
Source by: Newsweek
Over the years, many theories have been presented by scientists explaining the causes behind the death of dinosaurs. Among them, the most well-known theory is the Alvarez hypothesis, which was presented by two scientists Luis Alvarez and Walter Alvarez in 1980.
According to this theory, a gigantic asteroid fell from space and slammed into the earth about 66 million years ago drastically altering the planet’s climate. As a result, the earth’s atmosphere was filled with gas, debris, and dust making life impossible.
Source by: Salon.com
To support their theory, the scientists claimed they have discovered lots of iridium in different parts of the world. The element is believed to have been appeared along with the Cretaceous-Paleogene or K-Pg layer, which caps the ricks containing dinosaur fossils.
In 2016, a rock core was drilled to pull up a sample from the underwater part of Chicxulub, a 93-miles wide meteor crater discovered in 1991 on the edge of the Yucatán Peninsula. The sample showed that deadly amounts of vaporized rock and gases were sent into the atmosphere by a powerful impact. Hence, the iridium layer and a massive crater verified the credibility of the asteroid impact theory, which has so far presented a detailed and evidence-based explanation of the mass extinction of dinosaurs.
3. Unbearable Heat
Source by: NBC News
If you ask a scientist what killed the dinosaurs, you will get multiple answers with different arguments. But surprisingly, the Alvarez hypothesis is so famous that most of the explanations regarding the dino apocalypse emerge from this impact theory.
According to the scientists, as the bolide struck the earth, a huge amount of energy was released, which was nearly 2 million times more than that detonated by the most powerful nuclear bomb. Consequently, the earth’s surface was broiled by heat that ignited wildfires across the globe. Moreover, darkness prevailed all over as debris clouded the atmosphere.
Source by: European Commission
In oceans, miles-high tsunamis hit the land and washed over millions of creatures, including the dinosaurs. Besides, the heat resulted in volcanic eruptions and lead to massive earthquakes worldwide. Under these conditions, survival became impossible and the dinosaurs got extinct.
4. Horrendous Darkness
Source by: National Geographic
Darkness was another factor linked to an asteroid that killed the dinosaurs. Researchers have presented a very scary and creepy picture of the earth’s atmosphere as the meteor struck the planet millions of years ago.
Spewed by a large amount of heat released with the bolide’s impact, debris started raining from the sky and the atmosphere got roiled by powerful gusts. The wildfire produced soot and dust that dominated the sky like a giant sunlight-blocking shade. Volcanic eruptions added fuel to the fire as the air pollution kept on contaminating the atmosphere and forming a dark black layer over the entire planet.
Source by: ScienceAlert
The darkness lasted for a longer period ranging from a few months to several years. It blocked direct sunlight from coming to the earth and dropped the earth’s temperatures to freezing point. The absence of sunlight ceased the photosynthesis process and almost vanished all the plants.
As the herbivores found nothing to eat, they either died of starvation or were eaten by carnivores. A few months later, even the carnivores could not survive the unbearable atmosphere full of darkness, pollution, and lack of essential resources.
5. Volcanic Fury
Source by: ThoughtCo
Those scientists who consider meteor impact theory inconclusive believe that the earth itself is the culprit behind the mass extinction of dinosaurs. The presence of ancient lava flows like the Deccan Traps is attributed to massive lava outpourings dating back to the end of the Cretaceous.
Today, over 6000-feet thick volcanic rock layers are covering more than 200,000 square miles of earth. These layers indicate a vast and catastrophic eruptive event that could have changed the earth’s climate and biodiversity about 60 and 65 million years ago.
Source by: Visit Iceland
According to the proponents of the volcanic theory, the temperature of the earth’s atmosphere kept changing over the years, even before the impact event. Strong evidence emerging from the extinction of dinosaurs timeline shows the predators were experiencing a gradual decline much earlier than 66 million years ago.
Multiple volcanic activities might have caused a massive geographical transition leading to the dino apocalypse. Some scientists even combine both these theories and consider volcanism and meteor as primary factors behind the death of prehistoric creatures.
6. Buried Alive
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The meteor hitting the earth at high speed resulted in long-lasting effects. Scientists have collected some evidence to show the Chicxulub impact had generated a supersized tsunami that caused massive devastation. The landscape was filled with sediment dumped by the huge water waves arising from the Western Interior Seaway.
The sediment was made up of iridium, fossils of sea species, and glass debris vaporized by the meteor impact. The gills of fish fossils recovered from the tsunami deposits were packed with glass. This means the tsunami crushed the fish under the debris as it pushed across the landscape. Similar conclusions were made by Earth scientist Jan Smit while analyzing dinosaur tracks from two species. According to Smit, these dinosaurs were hit by the tsunami that buried them alive.
7. Cholecalciferol Deficiency
Source by: Smithsonian Magazine
A study published by Fraser (2019) in the Journal of Nutritional Science shows the deficiency of cholecalciferol could have stopped the embryo development in dinosaur eggs. As a result, young dinosaurs would die before hatching and become extinct for failing to reproduce.
Cholecalciferol plays a key role in avian embryonic development. An embryo in eggs from cholecalciferol-deficient dinosaurs could not grow with time and died before hatching. Similarly, the incubation times of dinosaur eggs were longer than those of descendants of modern-day birds.
Source by: Stanford University
Despite having sufficient 25-hydroxycholecalciferol in their bodies, female dinosaurs could not meet the minimum requirements of embryonic development during their prolonged period of incubation due to the lack of cholecalciferol in their eggs. Consequently, the cholecalciferol-deficient embryo would die during development and failed to hatch.
8. Combination of Events
Source by: Ntinal 0ceanic and Atmospheric Administration
The Deccan eruptions increased the earth’s temperatures by 7.8 Co and lead to a significant rise in atmospheric carbon dioxide. Thousands of years later, the planet experienced a smaller warming phase that lasted for an indefinite period. Both these warming phases also played a key role in the mass extinction of dinosaurs.
Geochemist Sierra Petersen says life on earth was not stable even before the meteor impact. The dinosaurs were under great stress and not living happily. Group killings, enmities, the quest for power encouraged large-sized dinosaurs to fight their counterparts. Then came this sudden impact that pushed them over the top and contributed to their extinction.
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In his one-two punch extinction hypothesis, Renne (2015) argued the rick enclosing the Deccan magma could not bear the shock of the meteor impact. Hence, hot magma came out of the molten rocks and formed bubbles by dissolving gases. The lava not only wiped out the whole vegetation but killed all the dinosaurs on the earth.
9. Problems with Eggs
Source by: Earth.com
Egg disorders also contributed to the extinction of dinosaurs, believes invertebrate fossil expert H.K. Erben. The analysis of fossilized dinosaur eggshell fragments showed two lethal disorders with dinosaurs’ eggs: Pathologically thin and multiple shell layers.
Pathologically thin eggs were easily breakable and dehydrated the embryos, while multi-layered eggs caused suffocation and resulted in the death of developing dinosaurs even before hatching.
Source by: Smithsonian Magazine
In another hypothesis in 1925, George Wieland called dinosaurs the egg-eaters, who would like eating eggs that caused their extinction. The trend of egg-eating was common among carnivore dinosaurs and is still found in some species of snakes and lizards.
Wieland’s hypothesis has been verified with fossil evidence that shows dinosaurs preyed on their eggs and infants. Nevertheless, the rate of egg-eating was too small to cause mass extinction. Hence, more arguments are required to fully support this theory.
10. Evolutionary Self-Destruction
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There are several creatures and animal species in global history that fell into obsolescence by developing undesirable body features. The same was the case with dinosaurs as some paleontologists believe it was evolutionary self-destruction that caused dinosaurs to go extinct.
Source by: Qur Planet
Before the wide acceptance of Darwin’s theory of natural selection, scientists believed in a confined evolution process of organisms. Proponents of this debunked notion argue that revolutionary inertia had made dinosaurs oversized, sluggish, and weirder over time. By spending their energies growing fierce and mammoth, dinosaurs became dumb and eventually unable to compete with other creatures on the earth.
However, this theory could not explain the prolonged domination of some of the biggest dinosaurs like Brachiosaurus and Stegosaurus.
FAQs About the Extinction of Dinosaurs
Source by: The Conversation
What Are the 3 Theories of Dinosaur Extinction?
Toxic volcanic gases and dust, asteroid impact, and climate change.
Which Extinction Killed Most of the Dinosaurs?
Cretaceous-tertiary Extinction in 65 million years ago.
Did Any Dinosaurs Survive?
Though scientists believe that dinosaurs died 65 million years ago, some species of dinosaurs evolved into birds and survived until now. It is estimated that there are more than 18,000 species of birds alive today.
Conclusion
Source by: Space.com
Paleontologists and scientists have been working on the extinction of prehistoric oddities for decades. Various explanations of the dino apocalypse have been presented to solve the mystery of their downfall after dominating for an inconceivably long period.
But whatever the culprit, it’s clear that the end of the dinosaurs also reveals important lessons about the effects of climate change on earth’s inhabitants.
Dinosaurs have become nonexistent, so it will be a little difficult to learn them. Don’t worry, our realistic puppet toys are effective teaching aids to pass on this knowledge to dinosaur lovers and the next generation.
If you are interested in content on this topic, maybe the blog Dinosaur lifespan: How long did a dinosaur live? You will like it too.
