Nelson, J.S., 1994

Hexanchiformes frill and cow sharks

Elasmobranchii

Heterodontiformes 195 M years

Shirai, S., 1996  | 

middle Jurassic

Marine

Fresh

Brackish

One dorsal fin, without spine; anal fin present; six or seven gill slits; eyes without nictitating fold; spiracle present but small and well behind eye.

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

Greek, exa = six + Greek, agkone, agko, to strangle, strangulate + Latin, forma = shape (Ref. 45335).

( n = 2 )
Chlamydoselachidae Hexanchidae

Ref.
[ e.g. 9948 ]      

Glossary
      [ e.g. oophagy ]