Nelson, J.S., 1994

Rajiformes skates and rays

Elasmobranchii

Torpediniformes 50 M years

Shirai, S., 1996  | 

early Tertiary

Marine

Fresh

Brackish

Gill openings ventral; anterior edge of the greatly enlarged pectoral fin attached to side of head, anterior to the gill openings; anal fin absent; eyes and spiracles on dorsal surface; anterior vertebrae fused to form a synarcual; suprascapulae of pectoral girdles joined dorsally over vertebral column and articulating with column of synarcual or fused with synarcual; nictitating membrane absent, cornea attached directly to skin around the eyes; body generally strongly depressed; jaws protrusible in most; teeth pavementlike; in most, water for breathing taken in chiefly through the spiracle rather than the mouth (except for those living off the bottom); most give birth to live young (some have eggs encased in a horny capsule); the snout may function as an electroreceptive organ (as may be true for all elasmobranchs).

Greek eulanein, elasmos = metal beaten out + Greek brangchia = gills. Ref. 45335.

Latin, raja = ray + Latin, forma = shape (Ref. 45335).

( n = 4 )
Anacanthobatidae Arhynchobatidae Gurgesiellidae Rajidae

Ref.
[ e.g. 9948 ]      

Glossary
      [ e.g. oophagy ]