Promicroceras planicosta (Sowerby)
Two perfect different sized Ammonites lying next to each other. Reminiscent of the Victorian bicycle know as a Penny farthing. With a negative. Very attractive specimen.
Jurassic, Upper Sinemurian, Obtusum Zone.
Black Ven, Charmouth / Lyme Regis, Dorset.
Largest Ammonite : 2.8 cm diam
