This species of Dactylioceras ammonite (Dactylioceras commune) from the Lower Jurassic period is found near Whitby, Yorkshire, England in concretions that must be broken open to reveal the approximately 180 million year old Orthoceras fossils inside. This set includes a positive Dactylioceras commune ammonite fossil on matrix and its negative impression in the concretion in which it was discovered. The pieces fit together.

Dimensions: 2-5/8″L  x 2″W x 1/2″H (negative half); 2-5/8″L x 2-3/4″W x 1-1/2″H (positive half), Weight: 86.87 g (negative half); 243 g (positive half)