Sharks come in all sizes. The largest is the whale shark, which has been known to get as large as 18 meters (60 feet). The smallest fits in your hand. And the great white shark is somewhere in the middle.
For the next 13 million years the enormous shark dominated the oceans until becoming extinct just 3.6 million years ago. O. megalodon was not only the biggest shark in the world, but one of the largest fish ever to exist. This giant shark is well-known for starring in the 2018 megalodon movie, The Meg.
Leedsichthys problematicus, meaning "Alfred Leed's problem-causing fish", was another prehistoric ocean giant. Estimates put Leedsichthys at approximately 16.5m long, substantially larger than the average Megalodon.
The second biggest shark in the world is the basking shark
While they don't get quite as large as whale sharks, the largest one ever reliably measured was 12.27 metres or just over 40 feet long. This is enough to net them the title of the world's second-largest shark.
No physical evidence has been found that would prove the creatures existence, although believers often point to the half-eaten carcasses of whales that sometimes wash ashore in the area.
It's thought that megalodon sharks became extinct in part due to climate change: as oceans grew colder, they may not have been able to regulate their temperatures as needed. Lack of prey could be behind the megalodon's extinction, as many marine animals and fish could not survive the cold temperatures.
The deep ocean is too cold for them to survive. Megalodons were extremely large animals that ate other extremely large animals.
Fossil remains of megalodon have been found in shallow tropical and temperate seas along the coastlines and continental shelf regions of all continents except Antarctica.
So far we've only found teeth and vertebrae of megalodons. Like other sharks, most of their skeleton is made from cartilage which doesn't preserve well in the fossil record. There's still lively debate in the scientific community about the modern species of sharks to which megalodon is most closely related.
The ocean no longer had room for a 50 foot megatooth shark, and to this day environmental conditions still wouldn't be able to carry such a massive predator. But, megalodon fossils are still found all over the world, and research is always being done on these incredible, fascinating creatures.
Mature megalodons likely did not have any predators, but newly birthed and juvenile individuals may have been vulnerable to other large predatory sharks, such as great hammerhead sharks (Sphyrna mokarran), whose ranges and nurseries are thought to have overlapped with those of megalodon from the end of the Miocene and ...
The battle for diminishing stocks of whales and other prey may have pushed the megalodon to extinction three million years ago. Environmental pressures, such as sea level changes, also played a role. The extinction of the megalodon has been an enduring mystery.
Indeed, the great white shark (Carcharodon carcharias) leads all other sharks in attacks on people and boats, as well as fatalities. Currently, the great white shark has been connected with a total of 354 total unprovoked shark attacks, including 57 fatalities [source: ISAF].
Megalodons are extinct. They died out about 3.5 million years ago. And scientists know this because, once again, they looked at the teeth.
The answer to the megalodon question is a resounding NO. Megalodon went extinct around 3.5 million years ago.
Great white sharks evolved about 4 million years ago, overlapping with megalodon for approximately 400,000 years, Live Science previously reported. At first, megalodon and great whites occupied separate niches and didn't compete with one another.
The title of largest land predator that ever walked on Earth goes to the Spinosaurus. This meat-eating dinosaur lived about 90-100 million years ago. It was about 60 feet long, 12 feet high, weighed at least 13 to 22 tons and had a skull roughly 6 feet long.
Sperm whales are the world's largest predator, with males reaching lengths of up to 67 feet (20.5 meters) and weights of up to 90 tons (81 metric tons). Females are slightly smaller, reaching lengths of up to 33 feet (10 meters). Sperm whales are found in all the world's oceans, but prefer deep waters.
Killer Whales
Great white sharks, to be exact. But the true ruler of the sea is the killer whale. Killer whales are apex predators, which means they have no natural predators. They hunt in packs, much like wolves, which are also at the top of their food chain.
As of yet, no one has seen a Megalodon, also known as a Megatooth shark, which reportedly went extinct around 2.58 million years ago, according to the Encyclopedia Britannica.
A history of the megalodon
5 million years ago – Great white sharks evolve, and likely compete with the massive Meg to eat the same marine mammals, such as whales. 3.5 million years ago – Otodus megalodon seemingly goes extinct around a time of upheaval, including cooling seas and a dip in the species it munched on.