Crocodile Against A Shark

Taxonomy and phylogeny
The English common name "crocodile shark" is derived from its Japanese name mizuwani (水鰐, literally "water crocodile"), which refers to its sharp teeth and habit of snapping vigorously when taken out of the water. Other common names for this species include Japanese ragged-tooth shark, Kamohara's sand-shark, and water crocodile. The crocodile shark was first described as Carcharias kamoharai in a 1936 issue of Zoological Magazine (Tokyo) by ichthyologist Kiyomatsu Matsubara, based on a 73.5 cm (28.9 in) long specimen found at the Koti Fish Market in Japan. The type specimen is a 1 m (3.3 ft) long adult male found at a fish market in Su-ao, Taiwan.
After being shuffled between the genera Carcharias and Odontaspis in the family Odontaspididae by various authors, in 1973 Leonard Compagno resurrected Jean Cadenat's 1963 subgenus Pseudocarcharias from synonymy for this species and placed it within its own family. The morphology of the crocodile shark suggests affinity with the megamouth shark (Megachasmidae), basking shark (Cetorhinidae), thresher sharks (Alopiidae), and mackerel sharks (Lamnidae). More recent phylogenetic analyses, based on mitochondrial DNA, have suggested that the crocodile shark is closely related to either the megamouth shark or the sand sharks (Odontaspididae). Alternately, analysis based on dentition suggests that the closest relatives of the crocodile shark are the thresher sharks, followed by the mackerel sharks. Fossil Pseudocarcharias teeth dating to the Serravallian age (13.6–11.6 Ma) of the Miocene epoch have been found in Italy, and are identical to those of the modern-day crocodile shark.