Ground shark information and info on the Carcharhiniformes also known as Ground sharks
Ground sharks, order Carcharhiniformes, are the largest order of sharks. With over 270 species, Ground sharks include a number of common types, such as the blue shark, catsharks, swellsharks, and sandbar shark.
Members of the Ground sharks order are characterized by the presence of a nictitating membrane over the eye, two dorsal fins, an anal fin, and five gill slits.
The families of the Ground sharks are expected to be revised; recent DNA studies show that some of the traditional groups are not monophyletic(two or more groups sharing a common ancestor).