The massive extinction that wiped out the dinosaurs 66 million years ago allowed SHARKS to thrive

A massive extinction that killed dinosaurs 66 million years ago meant that sharks could thrive. Researchers think that the loss of apex predators was one of the reasons for a profound increase in the biodiversity of sharks (impression of the artist)

A massive extinction that annihilated dinosaurs 66 million years ago allowed sharks to thrive, recent research has shown.

Sharks are one of the main groups of animals that survive the mass extinction of the Cretaceous-Paleogene.

However, a new study on hundreds of fossilized shark teeth has revealed that the species not only survived, but flourished after this devastating event.

The researchers believe that the loss of apex predators was one of the reasons for a profound increase in the biodiversity of sharks.

Scroll down to watch the video

A massive extinction that killed dinosaurs 66 million years ago meant that sharks could thrive. Researchers think that the loss of apex predators was one of the reasons for a profound increase in the biodiversity of sharks (impression of the artist)

A massive extinction that killed dinosaurs 66 million years ago meant that sharks could thrive. Researchers think that the loss of apex predators was one of the reasons for a profound increase in the biodiversity of sharks (impression of the artist)

Like many other vertebrate groups during the Cretaceous period (142-66 million years ago), the diversity of sharks looked very different from today's.

At that time, mackerel sharks (lamniformes) were the dominant order of sharks in the sea.

Mackerel sharks include large white sharks, mako, salmon, basking sharks and fox sharks.

This is in contrast to today, where Terrestrial sharks (carcharhiniformes) are the most diverse group of sharks on the planet, with a number of species of 200.

Terrestrial sharks include a large number of very common shark species, such as cat sharks, hammerhead sharks and marine sharks.

"Carcharhiniforms is the most common group of sharks today and it seems that the initial steps towards this domain began approximately 66 million years ago," said project leader and Ph.D. student at Uppsala University, Mohamad Bazzi.

The researchers explored variations in tooth shape in land sharks and mackerel sharks.

"Unlike other vertebrates, the cartilaginous skeletons of sharks do not easily fossilize, so our knowledge of these fish is largely limited to the thousands of isolated teeth they shed throughout their lives," said the Mr. Bazzi.

"Fortunately, shark teeth can tell us a lot about their biology, including information about diet, which can shed light on the mechanisms behind their extinction and survival."

Before the mass extinction event, mackerel sharks (lamniformes) were the dominant order of sharks in the sea. Mackerel sharks include large white shark (common image), mako shark, salmon shark, basking shark and shark fox

Before the mass extinction event, mackerel sharks (lamniformes) were the dominant order of sharks in the sea. Mackerel sharks include large white shark (common image), mako shark, salmon shark, basking shark and shark fox

Before the mass extinction event, mackerel sharks (lamniformes) were the dominant order of sharks in the sea. Mackerel sharks include large white shark (common image), mako shark, salmon shark, basking shark and shark fox

Now terrestrial sharks (carcharhiniformes) are the most diverse group of sharks that exist today, with more than 200 different species. This order includes several common sharks, such as cat sharks, hammerhead sharks (common image) and swell sharks.

Now terrestrial sharks (carcharhiniformes) are the most diverse group of sharks that exist today, with more than 200 different species. This order includes several common sharks, such as cat sharks, hammerhead sharks (common image) and swell sharks.

Now terrestrial sharks (carcharhiniformes) are the most diverse group of sharks that exist today, with more than 200 different species. This order includes several common sharks, such as cat sharks, hammerhead sharks (common image) and swell sharks.

Evidence suggests that there was a selective extinction of lamniformes and a subsequent proliferation of carcharhiniforms immediately after extinction.

The mechanisms that triggered these changes are still unknown, but researchers believe that availability in food would have played an important role.

The Cretaceous-Paleogene extinction saw significant losses in marine reptiles and cephalopods, including squids, and bony fish species thrived after extinction.

In addition, it is likely that the loss of apex predators, such as lamniformes and marine reptiles, has also benefited certain shark species.

The mass extinction was caused when the planet endured a period of global warming that lasted 100,000 years, triggered by a catastrophic asteroid impact.

Known as the asteroid Chicxulub, the collision threw billions of tons of carbon dioxide into the atmosphere, which caused the Earth's temperature to rise five degrees centigrade (nine degrees Fahrenheit).

"By studying their teeth, we can take a look at the life of extinct sharks," said Dr. Campione.

He said that "by understanding the mechanisms that have shaped their evolution in the past, we may be able to provide some ideas on how to mitigate more losses in current ecosystems."

Approximately 50 percent of the shark species in the International Union for the Conservation of Nature (IUCN) are considered endangered, threatened or near threatened.

Bazzi believes that more research is needed to understand the diversity patterns of other shark groups, along with the relationship between diet and tooth morphology.

This finding is reported this week in Current Biology.

HOW THE SHARKS WON THEIR REPUTATION WITHOUT ROUTES

Sharks are the most efficient predators on earth and have terrorized humans for a long time.

Its basic design has never really changed over the course of 200 million years and they are considered complex and intelligent.

Their teeth are the number one fear factor, and the large white teeth grow up to two and a half inches long.

Their prey is impaled on the pointed teeth of the lower jaw, where they saw sections of the flesh. The jagged edges of the teeth help with this process.

Their teeth are fragile and they break constantly, but they are also constantly growing back and on average there are 15 rows of teeth in the mouth at the same time.

Sharks are the most efficient predators on earth. Its basic design has never really changed over the course of 200 million years

Sharks are the most efficient predators on earth. Its basic design has never really changed over the course of 200 million years

Sharks are the most efficient predators on earth. Its basic design has never really changed over the course of 200 million years

Your speed is the fear factor number two.

They are very fast in the water compared to humans with the mako shark capable of reaching incredible 60 mph in gusts.

The great white can reach speeds of 25 mph.

In comparison, 5 mph is the fastest a human being can achieve.

The power and size of a shark also terrifies us.

The great white shark can grow up to 20 feet and, although it has no particular taste for humans, even an exploratory bite is enough to cut a man in half.

Most sharks release a human after their first bite, but sometimes that's all it takes to kill a person.

However, sharks have many more reasons to fear humans. We kill a million of them a year, often by simply cutting off their fins to turn them into soup and throwing the rest of the shark into the water, where they starve or drown.

(function() {
var _fbq = window._fbq || (window._fbq = []);
if (!_fbq.loaded) {
var fbds = document.createElement(‘script’);
fbds.async = true;
fbds.src = “http://connect.facebook.net/en_US/fbds.js”;
var s = document.getElementsByTagName(‘script’)[0];
s.parentNode.insertBefore(fbds, s);
_fbq.loaded = true;
}
_fbq.push([‘addPixelId’, ‘1401367413466420’]);
})();
window._fbq = window._fbq || [];
window._fbq.push([“track”, “PixelInitialized”, {}]);
.