Order Summary for Squaliformes

  Main Ref
:
  Order
:
Squaliformes bramble, sleeper and dogfish sharks
  Class
:
Elasmobranchii
  Sister Order
:
Squatiniformes 155 M years
  Ref..
:
  First Fossil Record
:
late Jurassic
  Occurs in
:
Marine
Fresh
Brackish
  Remark
:
Two dorsal fins, with or without spines; anal fin absent; five gill slits; spiracles present; nictitating lower eyelid absent. Many species are known from deep water.
  Classetymology
:
Greek eulanein, elasmos = metal beaten out + Greek brangchia = gills. Ref. 45335.
  Orderetymology
:
Latin, squalus, squalidus = weak, pale, with rough skin + Latin, forma = shape (Ref. 45335).
  Families
: