Macrokentriodon (SciiFii)

The giant killer dolphin (Macrokentriodon gigantohorridus), also known as the killer dolphin, is a species of giant dolphin (not part of the family Kentriodontidae, despite its name) that originally lived in what is now the United States during the Late Miocene as an extinct species of Macrokentriodon and was once extinct, but has since been brought back from extinction by SciiFii and introduced throughout the modern Pacific Ocean and the Atlantic Ocean to help boost biodiversity. The giant killer dolphin is one of the largest "natural" dolphins in history, growing to be about the size of a killer whale (Orcinus orca), hence its name, and the giant killer dolphin resembles an oversized bottlenose dolphin, but it is more robust and has larger, less numerous teeth. Also like killer whales, the giant killer dolphins have a diverse diet, although individual populations often specialize in particular types of prey. Some feed exclusively on fish, while others hunt marine mammals such as seals and other species of dolphin. They have been known to attack baleen whale calves, and even adult whales. Giant killer dolphins are apex predators, almost no other animals (besides megalodons, giant killer whales, or killer sperm whales) prey on them. Giant killer dolphins are highly social; some populations are composed of matrilineal family groups (pods) which are the most stable of any animal species. Their sophisticated hunting techniques and vocal behaviours, which are often specific to a particular group and passed across generations, have been described as manifestations of animal culture. The conservation status of the giant killer dolphin is Least Concern due to successful conservation efforts and the giant killer dolphin's wide range.