Dipturus

Astarloa, Juan Martin Díaz De, Mabragaña, Ezequiel & Hanner, Robert, 2008, Morphological and molecular evidence for a new species of longnose skate (Rajiformes: Rajidae: Dipturus) from Argentinean waters based on DNA barcoding, Zootaxa 1921, pp. 35-46 : 44

Key to species of Dipturus of the western South Atlantic

1a. Tail with more than one row of thorns.........................................................................................................2

1b. Tail with a single median row of thorns......................................................................................................5

2a. Dorsal and ventral surface of disc rough, scattered with small prickles; ocular and scapular thorns present but median disc thorns absent; adults up to 200 cm TL ...................................................... D. trachyderma

2b. Dorsal and ventral surface of disc relatively smooth, except interorbital region; scapular and median disc thorns either present or absent; adults less than 170 cm TL........................................................................3

3a. Scapular thorns and median disc thorns present; 5 or more nuchal thorns; interorbital region rough........4

3b. Scapular thorns and median disc thorns absent; a single nuchal thorn; interorbital region smooth.............. .................................................................................................................................................... D. chilensis

4a. Dorsal surface of disc smooth except interorbital region; ventral surface of disc with few prickles in the interbranchial space; 5 or 6 nuchal thorns ...................................................................................... D. menni

4b. Dorsal and ventral surface of disc with small scattered denticles; 8 nuchal thorns ........................ D.diehli

5a. Interbranchial space rough with small scattered prickles; dorsal surface of disc with numerous rounded whitish blotches; mouth width three times preoral length; a pair of scapular thorns present D. leptocauda

5b. Interbranchial space smooth; dorsal surface of disc purplish brown with no distinct ocelli or blotches; mouth width less than three times preoral length; scapular thorns absent .............. D. argentinensis n. sp.