Promicroceras planicosta (Sowerby)
Two pristine calcitic Ammonites lying virtually on top of each other. The 'lid' of the black shows the negative on one. Really unusual configuration.
Jurassic, Upper Sinemurian, Obtusum Zone.
Black Ven, Charmouth / Lyme Regis, Dorset.
Matrix : 10 x 7 cm.
