MEGALODON

the popular 2018 movie, "The Meg," pits modern humans against an enormous megalodon sharks, it's actually more than likely that the beast died out before humans even evolved. But it's difficult to pinpoint the exact date that the megalodon went extinct because the fossil record is incomplete.The megalodon, the largest shark in the world's ocean, possessed a streamlined and powerful body that allowed it to effortlessly navigate through water. Its tailfin moved in a side-to-side motion, while it obtained oxygen through gill slits located on both sides of its head.The scientific name, Otodus megalodon, signifies its immense dental structure, as its teeth are nearly three times larger than those of a contemporary great white shark. The fossilized remains of the megalodon shark, including its bones and teeth, provide valuable insights to scientists regarding its characteristics and extinction timeline.Like other elasmobranchs, megalodons have cartilage skeletons, which is a defining feature of this group of fishes. Cartilage is lighter than bone, allowing sharks to stay buoyant and swim long distances with less energy. However, cartilage is difficult to fossilize, so our knowledge about megalodons primarily comes from their teeth, vertebrae, and fossilized feces. The proposed shape of a megalodon is based on the anatomy of living sharks, and recent research suggests that it is closely related to make sharks rather than the Great White. There is much debate in the scientific community regarding the size of the megalodon shark. Based on the size of its teeth, some experts suggest that it could have grown up to 60 feet (18 meters) long, while others believe it may have been closer to 80 feet (25 meters) in length. According to Animal Diversity Web, modern great white sharks can grow up to 20 feet (6 m) in length. The whale shark (Rhincodon types) is even larger, reaching up to 32 feet (9.7 m). The giant oarfish, which is the longest bony fish alive, can reach up to 36 feet (11 m), as reported by the Florida Museum of Natural History.

"Original calculations greatly overestimated the size of megalodon," Marty Becker, a William Paterson University professor of environmental science who studies shark paleontology, told Live Science. "This is in part related to the fact that the megalodon fossil record is dominated almost exclusively by teeth. Current calculations indicate that megalodon may have achieved lengths up to 10 meters [around 33 feet] and nothing like what is currently featured in the summer 2018 movie 'The Meg.'"

In 2014, a research group at the University of Zurich used optimal linear estimation to study megalodon fossils and determine their age. The research, published in the journal PLOS ONE, revealed that most of the fossils date back to the middle Miocene epoch to the Pliocene epoch, approximately 15.9 million to 2.6 million years ago. The authors noted that all evidence of the creature's existence ceased 2.6 million years ago in the current fossil record. It is interesting to note that our earliest Homo sapiens ancestors emerged only 2.5 million years ago, during the Pleistocene epoch, as stated by the University of California Museum of Paleontology. According to the Zurich study, only 6 out of 10,000 simulations showed a 1% chance of the survival of giant sharks. However, the researchers rejected the popular claims of present-day survival of O. megalodon. Scientists agree that megalodon sharks are extinct as no recent evidence or fossils younger than 2.6 million years old have been discovered.

According to Becker, megalodon and whales had a co-evolutionary relationship, with whales being a primary food source for the former. Whales, being mammals, had the ability to regulate their body temperature and migrate towards colder waters. Although the exact extent of their thermoregulatory capabilities is still being studied, it is believed that megalodon's inability to hunt whales in colder waters was a major factor contributing to their extinction.

The megalodon, being the largest predator of its time, consumed a wide range of prey such as toothed and baleen whales, seals, sea cows, and sea turtles. Additionally, it opportunistically fed on fish and other sharks. Whale fossils often exhibit distinct gashes caused by megalodon teeth, and occasionally, a complete megalodon tooth is discovered embedded in a whale bone. Scientists estimate that a bite from a megalodon jaw could exert a force of up to 40,000 pounds, making it the most powerful bite in the animal kingdom.

Visitors to the Sant Ocean Hall at the National Museum of Natural History in Washington, D.C. can capture a memorable moment with a life-size replica of a megalodon. The model, which measures 52 feet and represents an average-sized female megalodon, features a gaping jaw filled with large teeth that cannot be replicated in a living shark. The exhibit was added to the museum's West courtyard in Spring 2019.