Chondrichthyes orders

The Lamniformes (, from Greek lamna "fish of prey") are an order of sharks commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, such as the great white and mako sharks as well as less familiar ones, such as the goblin shark and megamouth shark.

thumb|253px|Ground sharks, like this blacknose shark, have a [[nictitating membrane which can be drawn over the eye to protect it.]]

Rajiformes is one of the four orders in the clade Batomorphi, often referred to as the superorder Batoidea, flattened cartilaginous fishes related to sharks. Rajiforms are distinguished by the presence of greatly enlarged pectoral fins, which reach as far forward as the sides of the head, with a generally flattened body. The undulatory pectoral fin motion diagnostic to this taxon is known as rajiform locomotion. The eyes and spiracles are located on the upper surface of the head and the gill slits are on the underside of the body. Most species give birth to live young, although some lay eggs e

The Squaliformes are an order of sharks that includes about 126 species in seven families.

The Hexanchiformes /hɛkˈsæŋkɪfɔːrmiːz/ are a primitive order of sharks, numbering just five extant species in two families, Chlamydoselachidae and Hexanchidae. Chlamydoselachidae are also known as frilled sharks, these sharks are very rare fishes and typically reside in deeper waters. Hexanchidae are also known as cow sharks and are the lesser known of the two types of Hexanchiformes and also reside in deep waters.

Myliobatiformes (), commonly known as stingrays, are one of the four orders of batoids, cartilaginous fishes related to sharks. They are members of the subclass elasmobranchs. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown the Myliobatiformes to be a monophyletic group, and its more derived members evolved their highly flattened shapes independently of the skates.

Rhinopristiformes (rhino rays) is an order of rays, cartilaginous fishes related to sharks, containing shovelnose rays and allied groups.

REDIRECT Sawshark

Squatiniformes is an order of sharks belonging to Squalomorphi. It contains only a single living genus Squatina, commonly known as angelsharks. The oldest genus of the order, Pseudorhina is known from the Late Jurassic of Europe. Three other genera, Cretasquatina, Cretascyllium and Parasquatina are known from Cretaceous fossils from North America and Europe, though the placement of Parasquatina in the order has been questioned. All living and extinct members of the order share a similar body morphology with a highly flattened body with enlarged pectoral and pelvic fins suggestive of a bottom-d

Heterodontiformes is an order of sharks in the superorder Galeomorphi. It includes the bullhead sharks (genus Heterodontus), and several extinct genera. The earliest known members of the group are from the Early Jurassic (Toarcian), around 175 million years ago. Several extinct genera are known from the Jurassic, with all except Paracestracion only known from isolated teeth. The teeth of heterodontiforms exhibit differentation, with the front teeth having well developed cusps to grasp prey, while the back teeth are flattened, and serve to crush hard shelled prey. They inhabit shallow littoral

Orodontiformes is an extinct group of cartilaginous fish, known from the Late Devonian and Carboniferous periods. They are part of Euchondrocephali (Holocephali sensu lato), making their closest living relatives chimaeras. Most members are only known from teeth, which are low and rounded, and designed for crushing prey (durophagy). The group in its totality has been described as "undoubtedly artificial" (i.e. non-monophyletic). Several species of Orodus are known from specimens preserving the body as well as the teeth.