Carcharhiniformes

Carcharhiniformes is the largest order of sharks. Also known as Ground sharks or Whaler sharks, this group contains over 270 species of shark. It includes some common ones like the Blue shark, Bull shark, Tiger shark and the hammerhead sharks.
Ground sharks have a special membrane which protects their eyes when needed. They have two dorsal fins, an anal fin, and five gill slits.
Ground sharks are found in open oceans, seas, estuaries, and brackish waters.
Families.
There are eight families in this order: