Every Week Is Shark WeekLists about the world's most perfect predator, which has stalked every sea and consumed whatever it wishes for the last 420 million years.
Sharks are some of the most fascinating and frightening creatures on the planet, but they are often misunderstood and threatened as a result. Being some of the oldest still-living fish on Earth, there have been thousands of species swimming through the oceans over the eons of planetary history. While there are numerous sharks still swimming in the ocean today, there are far more extinct sharks who've taken their last swim—not to mention several endangered shark species.
A list of extinct sharks will absolutely include the infamous megalodon, otherwise known as "the Meg" thanks to a 2018 film. Even with a famous shark that has been lost to history, there are many more that have died out over the millions of years sharks have been swimming in the ocean. Whatever ended up causing these amazing fish to leave our oceans forever, they make up some of the more interesting examples of extinct sharks the world will never know.
History - The megaladon is likely the most famous extinct shark thanks to films like The Meg and various depictions on the Discovery Channel's Shark Week. These giant predators were the largest predatory sharks to have existed between 23 and 2.6 million years ago. They likely went extinct due to competition resulting in a reduction in its food source. Contrary to popular urban legend, the megaladon is extinct and is not roaming the deepest, darkest depths of the ocean.
Physical Description - They looked much like a modern great white shark, though they were not related to the extant species.
Size - Up to 59' in length and weighing in at approximately 33.9 metric tons.
Location - Their fossils have been found along the coastline of every major land mass except Antarctica. It is believed they preferred subtropical temperate areas and remained close to the shoreline.
Modern Relatives - Its family (Otodontidae) died out, but it shares a common ancestor from the Early Cretaceous with most extant sharks.
History - Negaprion Eurybathrodon was a species of lemon shark that swam the oceans globally from the Late Eocene to the Pilocene some 2.5 to 56 million years ago. Their fossilized teeth are some of the most abundant in the world, which has led to numerous collectors misidentifying them as other extant species of shark.
Physical Description - They looked much like the extant members of the Nagaprion genus. Their body shape was a classic shark-form and they featured two dorsal fins.
Size - They likely reached a length of approximately 12' at the largest.
Location - They had a global distribution, which is indicated by the presence of their teeth found all over the world.
Modern Relatives - The two remaining species of lemon shark are the closest modern relatives.
History - The Hemipristis serra was a species of weasel shark, which swam the oceans during the Miocene epoch some 5 to 23 million years ago. It was considerably larger than any of its modern relatives and possessed larger teeth. Markings from these teeth have been identified in the bones of Metaxytherium, an ancient animal similar to a modern day manatee.
Physical Description - It shares similar morphological features to the modern day weasel sharks, though it was considerably larger.
Size - They reached a length of approximately 8' to 16'.
Location - The Atlantic Ocean with large deposits of their teeth found in sediments of southern Florida.
Modern Relatives - The snaggletooth shark is the closest living relative.
History - Pristiophorus striatus was a species of sawshark that roamed the seas during the Miocene period some 5 to 23 million years ago. It shared many similarities with modern sawsharks and falls within the same genus (Pristiophorus), which remains extant with seven known species.
Physical Description - They likely had five gills and featured an elongated snout with rostral sawteeth along the outside of the basal ledges. Their larger teeth were not serrated.
Size - They reached a length of approximately 3.6'.
Location - Their remains have been found only in modern day Slovakia.
Modern Relatives - All extant species of sawshark.
History - Otodus was a genus of mackerel shark that lived during the Paleocene to the Miocene epoch some 66 to 5.3 million years ago. Its name is derived from the Greek word meaning "ear-shaped tooth". While its teeth have filled the fossil record, little has been found related to the skeleton due to its composition of cartilage instead of bone. Some fossilized vertebral centra have been located. It was likely one of the top predators of its time and may have fed on other sharks and bony fish.
Physical Description - These were considerably large predators, which bore a traditional shark body shape similar to a modern great white.
Size - Otodus was one of the largest predatory sharks, reaching a length of up to 40'. The largest tooth found measured 4.1" in height.
Location - Otodus was distributed worldwide.
Modern Relatives - Otodus evolved into the genus Carcharocles, which includes megaladon.
History - The Isurus planus, also known as the "hooked-tooth mako" was a species of extinct shark that lived during the Micoene epoch between 5 and 23 million years ago. They were relatively large predators that probably fed upon fish, pinnipeds, and small whales.
Physical Description - Most of what is known about Isurus planus comes from its teeth, which are unserrated, sharp, and slightly curved resembling a hook, which is where its name comes from.
Size - Their total size may have been as much as around 20', comparable to a modern great white.
Location - Their fossils have been found in the Pacific Rim including areas of Australia up to Japan and across to California.
Modern Relatives - The closest living relative is the mako shark.
