Megalodon, also known as Otodus megalodon, was an extinct species of massive shark. However, its true appearance remains a subject of debate. Megalodon lived approximately 23 to 3.6 million years ago, spanning from the Early Pisces to the Pliocene epochs. Initially, it was believed to be a member of the Lamnidae family and closely related to the great white shark (Carcharodon carcharias). Later, it was discovered that Megalodon actually belonged to the extinct Otodontinae family, which diverged from white sharks.

Recent findings suggest that Megalodon may have been even larger than previously estimated, with a 16-meter-long (52 ft) individual potentially weighing over 61.5 metric tons (67.8 short tons). Such a massive creature would have required a daily intake of 98,175 kcal. Megalodon possessed thick, robust teeth designed for capturing prey and breaking bones. Its powerful jaws could exert a bite force ranging from 108,500 to 182,200 newtons (24,390 to 40,960 lbf).

Megalodon is now classified as a member of the Otodontidae family, genus Otodus, rather than being classified as Carcharodon within the Lamnidae family. The initial association with the great white shark was due to dental similarities, but it is now believed to be a case of convergent evolution. Current research suggests that the great white shark is more closely related to the extinct broad-toothed mako shark, as evidenced by their similar dentition. Megalodon teeth, on the other hand, have much finer serrations than those of the great white shark. The great white shark shares a more recent common ancestor with the mako shark, dating back around 4 million years.

There are differing interpretations regarding the physical appearance of Megalodon. One view suggests that it had a robust build similar to that of the great white shark, with blunter and wider jaws. The fins would have had a similar shape but would be thicker due to its size. Another interpretation suggests similarities with the whale shark (Rhincodon typus) or basking shark (Cetorhinus maximus). This would entail a crescent-shaped tail fin, small anal and second dorsal fins, and the presence of caudal keels on either side of the tail fin. Such physical characteristics are common among large aquatic animals like whales, tuna, and other sharks, as they help reduce drag during swimming. The head shape could vary between species, as most drag-reducing adaptations are concentrated toward the tail end of the animal.

Estimates of Megalodon’s size vary depending on the method used, with maximum total length estimates ranging from 14.2 to 20.3 meters (47 to 67 ft). A study in 2015 estimated the average total body length to be 10.5 meters (34 ft) based on 544 Megalodon teeth found across different geological periods and regions, including adults and juveniles. For comparison, large great white sharks typically measure around 6 meters (20 ft) in length, although some reports suggest larger sizes. The whale shark holds the title for the largest living fish, with reports of females measuring up to 15 meters (49 ft) in precaudal length and an estimated total length of 18.8 meters (62 ft).

In conclusion, while we can draw connections between Megalodon and modern sharks, it is challenging to determine its precise appearance based solely on a collection of teeth and jaws. The sheer size and magnitude of its jaws suggest a formidable creature, but further details about its overall physical characteristics remain uncertain.