Sphaeroceras brongniarti (Sowerby)
Matrix free specimen. Developed to centre both side. A section of the outer whorl shows some sort of gross pathology with a raised ridges and a disruption to the ribbing. Very unusual.
Jurassic, Bajocian, Humphriesianum Zone.
Oborne Wood, Sherbourne, Dorset.
Ammonite : 3.2 cm diam.
