Eugassiceras resupinatum (Simpson) & Arnioceras semicostatum Young & Bird.
Square base cut block of grey limestone. On the upper surface are two beautifully preserved calcitic Ammonites. Both developed to the protoconch. Nice example of this particular pairing which includes the zonal index species.
Jurassic, Lower Sinemurian, Semicostatum Zone.
Black Ven, Charmouth, Dorset.
Matrix : 9 x 6.4 x 4 cm.