Myliobatiformes () is one of the four

orders Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

of batoids, cartilaginous fishes related to sharks. They were formerly included in the order

Rajiformes Rajiformes is one of the four orders in 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 hea ...

, but more recent

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

studies have shown the myliobatiforms to be a

monophyletic group A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

, and its more

derived Derive may refer to: * Derive (computer algebra system), a commercial system made by Texas Instruments * ''Dérive'' (magazine), an Austrian science magazine on urbanism *Dérive, a psychogeographical concept See also * *Derivation (disambiguatio ...

members evolved their highly flattened shapes independently of the

skate Skate or Skates may refer to: Fish *Skate (fish), several genera of fish belonging to the family Rajidae * Pygmy skates, several genera of fish belonging to the family Gurgesiellidae * Smooth skates or leg skates, several genera of fish belongin ...

Classification

Nelson's ''

Fishes of the World ''Fishes of the World'' by the American ichthyologist Joseph S. Nelson (1937–2011) is a standard reference for fish systematics. Now in its fifth edition (2016), the work is a comprehensive overview of the diversity and classification of the ...

'' arranges the Myliobatiformes as: *Suborder

Platyrhinoidei The Platyrhinidae are a family of rays, commonly known as thornbacks due to their dorsal rows of large thorns. They resemble guitarfishes in shape. Though traditionally classified with stingrays, molecular evidence suggests they are more closely ...

**Family

Platyrhinidae The Platyrhinidae are a family of rays, commonly known as thornbacks due to their dorsal rows of large thorns. They resemble guitarfishes in shape. Though traditionally classified with stingrays, molecular evidence suggests they are more closely ...

(thornbacks) *Suborder

Zanobatoidei The panrays are a genus, ''Zanobatus'', of rays found in coastal parts of the warm East Atlantic Ocean, ranging from Morocco to Angola. It is the only genus in the family Zanobatidae, which traditionally has been included in the Myliobatiformes ...

**Family

Zanobatidae The panrays are a genus, ''Zanobatus'', of rays found in coastal parts of the warm East Atlantic Ocean, ranging from Morocco to Angola. It is the only genus in the family Zanobatidae, which traditionally has been included in the Myliobatiformes ...

(panrays) *Suborder Myliobatoidei ( stingrays) **Superfamily Hexatrygonoidea ***Family

Hexatrygonidae The sixgill stingray (''Hexatrygon bickelli'') is a species of stingray and the only extant member of the family Hexatrygonidae. Although several species of sixgill stingrays have been described historically, they may represent variations in a ...

(sixgill stingray) **Superfamily Urolophoidea ***Family

Plesiobatidae The deepwater stingray or giant stingaree (''Plesiobatis daviesi'') is a species of stingray and the sole member of the family Plesiobatidae. It is widely distributed in the Indo-Pacific, typically over fine sediments on the upper continental ...

(deepwater stingray) ***Family

Urolophidae The Urolophidae are a family of rays in the order Myliobatiformes, commonly known as stingarees or round stingrays. This family formerly included the genera '' Urobatis'' and '' Urotrygon'' of the Americas, which are presently recognized as formi ...

(round stingrays) **Superfamily

Urotrygonoidea Urotrygonidae is a family of rays in the order Myliobatiformes, commonly referred to as the American round stingrays or round rays. They are native to the tropical and warm temperate marine waters of the Americas. The two genera in this family ...

***Family

Urotrygonidae Urotrygonidae is a family of rays in the order Myliobatiformes, commonly referred to as the American round stingrays or round rays. They are native to the tropical and warm temperate marine waters of the Americas. The two genera in this family ...

(American round stingrays) **Superfamily Dasyatoidea ***Family Dasyatidae (whiptail stingrays) ***Family

Potamotrygonidae River stingrays or freshwater stingrays are Neotropical freshwater fishes of the family Potamotrygonidae in the order Myliobatiformes, one of the four orders of batoids, cartilaginous fishes related to sharks. They are found in rivers in tropic ...

(river stingrays) ***Family

Gymnuridae The butterfly rays are the rays forming the genus ''Gymnura'' and the family Gymnuridae. They are found in warm oceans worldwide, and occasionally in estuaries. The body of butterfly rays is flattened and surrounded by an extremely broad disc f ...

(butterfly rays) ***Family Myliobatidae (eagle rays) ****Subfamily Myliobatinae (eagle rays) ****Subfamily Mobulinae (manta rays, devil rays) ****Subfamily Rhinopterinae (cownose rays) The family Aetobatidae is recognised by some authorities. It contains the genus ''Aetobatus'', which is otherwise part of Myliobatinae.

References

{{Taxonbar, from=Q796580 Rays Taxa named by Leonard Compagno Cartilaginous fish orders