Galaticeras jacksoni ( Howarth & Donovan 1964)
Exceptionally large specimen of this particular species. With a white calcite vein running across the middle of the Ammonite. This really is a 'monster'
Jurassic, Upper Sinemurian, Obtusum Zone.
Black Ven, Charmouth / Lyme Regis, Dorset.
Ammonite : 2.6 cm diam.