Order Summary for Notacanthiformes

  Main Ref
:
  Order
:
Notacanthiformes halosaurs and deep-sea spiny eels
  Class
:
Actinopterygii
  Sister Order
:
Albuliformes 80 M years
  Ref..
:
  First Fossil Record
:
late Cretaceous
  Occurs in
:
Marine
Fresh
Brackish
  Remark
:
Body eel-like; posteriorly directed spine on dorsal edge of rear of maxilla; premaxilla and maxilla bordering upper jaw; gill membranes separate; pectoral fins relatively high on body; pelvic fins abdominal, with 7-11 rays (the two fins are usually connected by a membrane); anal fin base long and merged with what remains of the caudal fin; caudal fin skeleton reduced or absent; tail easily regenerated when lost; branchiostegal rays 5-23; swim bladder present. Some have photophores.
  Classetymology
:
Greek aktis = ray, thunderbolt, beam + Greek pterygion, diminutive of pteryx = wing, fin. Ref. 45335.
  Orderetymology
:
Greek, noton = back + Greek, akantha = thorn + Latin, forma = shape (Ref. 45335).
  Families
: