How Dinosaurs Were Extinct

Author: Peter Berry
Date Of Creation: 20 February 2021
Update Date: 3 November 2024
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How Dinosaurs Went Extinct!
Video: How Dinosaurs Went Extinct!

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Throughout our planet's history, few creatures have managed to capture human fascination like dinosaurs. The colossal animals that once populated the Earth have now filled our screens, books and even our toy boxes for as long as we can remember. However, after a lifetime of living with the memory of dinosaurs, do we know them as well as we thought?

Then, in PeritoAnimal, we'll dive into one of the great mysteries of evolution: çHow did dinosaurs go extinct?

When did dinosaurs exist?

We call dinosaurs the reptiles included in the superorder dinosaur, from the greek deinos, which means "terrible", and sauros, which translates as "lizard", although we shouldn't confuse dinosaurs with lizards, as they belong to two different reptile categories.


The fossil record indicates that dinosaurs starred in the was Mesozoic, known as the "Age of the Great Reptiles". The oldest dinosaur fossil found to date (a specimen of the species Nyasasaurus parringtoni) has approximately 243 million years and therefore belongs to the Middle Triassic period. At that time, the present continents were linked together forming the great land mass known as Pangea. The fact that the continents were not, at the time, separated by the sea, allowed the dinosaurs to spread rapidly across the Earth's surface. Likewise, the division of Pangea into the continental blocks of Laurasia and Gondwana during the beginning of the Jurassic period it stimulated the diversification of dinosaurs, giving rise to many different species.


Dinosaur classification

This diversification favored the appearance of dinosaurs with very varied characteristics, traditionally classified into two orders, according to the orientation of their pelvis:

  • Saurischians (Saurischia): individuals included in this category had a vertically oriented pubic ramus. They were divided into two main lineages: theropods (like the Velociraptor or the Allosaurus) and sauropods (such as Diplodocus or the brontosaurus).
  • Ornithischians (Ornithsia): the pubic branch of the members of this group was oriented diagonally. This order encompasses two main lineages: the tyerophores (such as the Stegosaurus or the Ankylosaurus) and cerapods (such as the Pachycephalosaurus or the Triceratops).

Within these categories, we can find animals of highly variable span, from the Compsognatus, the smallest dinosaur discovered to date, similar in size to a chicken, to the formidable brachiosaurus, which reached an impressive height of 12 meters.


Dinosaurs also had the most diverse forms of food. Although it is difficult to confirm with certainty the specific diet of each species, it is considered that were mostly herbivores, although several carnivorous dinosaurs also existed, some of which preyed on other dinosaurs, such as the famous Tyrannosaurus rex. Certain species, such as the Baryonyx, also fed on fish. There were dinosaurs that followed an omnivorous diet, and many of them did not reject eating carrion. For more details, don't miss the article on the types of dinosaurs that once existed."

Although this diversity of life forms facilitated the colonization of the entire planet during the Mesozoic era, the dinosaur empire came to an end with the last blows of the Cretaceous period, 66 million years ago.

Dinosaur Extinction Theories

The extinction of dinosaurs is, for paleontology, a puzzle of a thousand pieces and difficult to solve. Was it caused by a single determining factor or was it the result of a disastrous combination of several events? Was it a sudden and abrupt process or a gradual process over time?

The main obstacle to explaining this mysterious phenomenon is the incomplete nature of the fossil record: not all specimens are conserved in the terrestrial substrate, which provides an imperfect idea of ​​the reality of the time. But thanks to continuous technological progress, new data have been revealed in recent decades, which allows us to propose a little clearer answers to the question of how dinosaurs became extinct.

When did dinosaurs become extinct?

Radioisotope dating locates the extinction of dinosaurs approximately 66 million years ago. So when did dinosaurs go extinct? During the period late cretaceous of the Mesozoic era. Our planet at the time was a place of unstable environment, with radical changes in temperature and sea level. These changing climatic conditions could lead to the loss of some key species in ecosystems at the time, altering the food chains of the individuals that remained.

How did dinosaurs go extinct?

So was the picture when the volcanic eruptions from the Deccan traps started in India, releasing sulfur and carbon gases in large quantities and promoting global warming and acid rain.

As if that wasn't enough, it didn't take long for the main suspect in the extinction of dinosaurs to arrive: 66 million years ago, the Earth was visited by a asteroid approximately 10 km in diameter, which collided with the now called Yucatán Peninsula in Mexico and left as a reminder the crater of Chicxulub, whose extension is 180 kilometers.

But this huge gap in the Earth's surface wasn't the only thing the meteor brought: the brutal collision caused a seismic catastrophe that shook the Earth. In addition, the impact zone was rich in sulfates and carbonates, which were released into the atmosphere producing acid rain and temporarily destroying the ozone layer. It is also believed that the dust raised by the cataclysm may have placed a layer of darkness between the Sun and Earth, slowing down the rate of photosynthesis and damaging plant species. The deterioration of plants would have resulted in the ruin of herbivorous dinosaurs, which would lead carnivores with them to the precipice of extinction. Thus, due to landforms and climate change, dinosaurs couldn't feed and therefore they began to die.

Why did dinosaurs go extinct?

The information unearthed so far has given rise to a plethora of theories about the possible cause of dinosaur extinction, as you saw in the previous section. Some people attach more importance to the meteorite impact as the abrupt cause of the dinosaurs' extinction; others think that environmental fluctuations and the intense volcanic activity of the time spurred its gradual disappearance. The proponents of a hybrid hypothesis They also stand out: this theory proposes that weather conditions and raging volcanism fueled the slow decline of dinosaur populations, which were already in a vulnerable position when the meteorite delivered the coup de grace.

Then, what caused the extinction of the dinosaurs? Although we cannot say with certainty, the hybrid hypothesis is the most supported theory, as it argues that there were several factors that led to the disappearance of dinosaurs during the Late Cretaceous period.

Animals that survived the extinction of dinosaurs

Although the catastrophe that caused the extinction of the dinosaurs had a global impact, some animal species managed to survive and thrive after the cataclysm. This is the case for some groups of small mammals, like the Kimbetopsalis simmonsae, a species whose individuals are herbivores that look like a beaver. Why were dinosaurs extinct and not mammals? This is due to the fact that, being smaller, they needed less food and were better able to adapt to their new environment.

Survived also right insects, horseshoe crabs and the archaic ancestors of today's crocodiles, sea turtles and sharks. Also, dinosaur lovers who are afflicted thinking they'll never be able to see an iguanodon or pterodactyl should remember that these prehistoric creatures never completely disappeared - some still survive among us. In fact, it is very common to see them on a beautiful day walking in the countryside or when we run through the streets of our cities. Although it may sound incredible, we are talking about the birds.

During the Jurassic period, theropod dinosaurs underwent a long process of evolution, giving rise to several species of archaic birds that coexisted with the rest of the dinosaurs. When the Cretaceous hecatomb occurred, some of these primitive birds managed to survive, evolving and diversifying until reaching the present day.

Unfortunately, these modern dinosaurs are also now in decline, and it's easy to identify the reason: it's about the human impact. The destruction of their habitats, the introduction of competing exotic animals, global warming, hunting and poisoning have caused the disappearance of a total of 182 species of birds since 1500, while around 2000 others are under some degree of threat. Our unconsciousness is the accelerated meteor that hovers over the planet.

We are said to be witnessing the sixth great live and color mass extinction. If we want to prevent the disappearance of the last dinosaurs, we need to fight for bird conservation and reserve a high degree of respect and admiration for the feathered aeronauts we meet daily: the pigeons, magpies and sparrows we are used to seeing carry on their fragile bones hollow a legacy of giants.

What happened after the extinction of the dinosaurs?

The impact of meteorites and volcanism favored the generation of seismic phenomena and fires that fueled global warming. Later, however, the appearance of dust and ash that darkened the atmosphere and blocked the passage of sunlight produced a cooling of the planet. This abrupt transition between extreme temperatures caused the extinction of approximately 75% of the species that inhabited the Earth at the time.

Still, it didn't take long for life to reappear in this devastated environment. The layer of atmospheric dust began to disintegrate, letting light through. Mosses and ferns began to grow in the worst-affected areas. The less affected aquatic habitats proliferated. The scarce fauna that managed to survive the disaster multiplied, evolved and spread across the planet. After the fifth mass extinction that devastated Earth's biodiversity, the world kept turning.

If you want to read more articles similar to How Dinosaurs Were Extinct, we recommend that you enter our Curiosities section of the animal world.