Cladoselache (SciiFii)

The ancient shark (Cladoselache marinus) is a species of shark that originally lived during the Devonian period in what is now North America as an extinct species of Cladoselache and was once extinct, but has since been brought back from extinction by SciiFii and introduced throughout the world's oceans to help boost biodiversity. The ancient shark usually grows to be up to 5.9 feet (1.8 metres) long. It is known to be a fast-moving and fairly agile predator due to its streamlined body and deeply forked tail like other sharks such as mako sharks. Due to the ancient shark being known as being one of, if not, the oldest known shark on Earth, it is one of the best known of the originally-prehistoric sharks. The ancient shark has six gill slits, and a short, rounded snout that has a terminal mouth opening at the front of the skull. It has a very weak jaw joint compared with other sharks, but it compensates for that with very strong jaw-closing muscles. It also has a blade-like structure which is positioned in front of the dorsal fins. These anatomical features make swimming easier and faster. The ancient shark, unlike most sharks, is almost entirely devoid of scales with the exception of small cusped scales on the edges of the fins, mouth and around the eyes. The ancient shark is a fast and agile carnivore that primarily preys on fish, crustaceans, small sea scorpions, and other sea-going animals smaller than itself. Unlike most other sharks, the ancient shark lacks claspers, organs found in modern sharks that are responsible for the transfer of sperm during reproduction. Instead, the ancient shark reproduces in a manner similar to other primitive fish such as lampreys, traveling into rivers and lakes to spawn their eggs resembling those of horn sharks, before heading back to the oceans. The eggs hatch around 3 months later as hatchlings, where they stay in lakes and rivers for 5 months before heading out to the oceans when they are almost fully-grown. The conservation status of the ancient shark is Least Concern due to successful conservation efforts, the ancient shark's wide range and its tolerance to most of the human activities. The ancient shark does not pose any danger to people or their pets due to the ancient shark's docile and tame nature towards land animals, so humans tolerate their presence.