The Carboniferous Period was about 360 to 286 million years ago, and scientists have dubbed the era like the Golden Age of Sharks because shark diversity flourished. By the end of the period, there were approximately 45 families of sharks!
The Falcatus falcatus were tiny but mighty; scientists estimated that the sharks were six inches in length. One preserved fossil even depicts a couple of the sharks mating, with the larger female grabbing the male by its head spine!
The Elegestolepis is shrouded in much mystery. Scientists only know what they could gleam from fossilized placoid scales. It is believed that the sharks were covered in placoid scales that were hydro dynamically shaped to keep down water resistance.
These sharks were believed to have lived in the late Silurian period, more than 420 million years ago. They are thought to be one of the earliest sharks, even predating much of the life on land.
The borneo shark was once thought to have been extinct. The scarce species was discovered in 2004. The small gray shark is only 26 inches in length. The slender body includes a long pointed snout and a second dorsal fin behind its anal fin. The sharks mostly feed on bony fishes.
It is the only member of its genus to have a row of enlarged pores above the corners of its mouth. Before its sighting, the last recorded time a Borneo shark was spotted was in 1937. The shark continues to gain conservation concern from scientists.
Previously known as the false smalltail shark, the Carcharhinus obsolerus has not been seen in more than 80 years, and scientists believe they may have become extinct. The species was known to swim in the Western Central Pacific Ocean area, and the last three specimens found were in Borneo, Vietnam, and Thailand.
Although they have not been seen since 1937, scientists are hopeful that the lost sharks are not entirely lost. The rediscovery of the borneo sharks gives them hope that these sharks could be found again.