Hemicidaris intermedia Echinoid fossil of Oxfordonian age, that's approximately 157 to 163 Mya during the Jurassic period. Hemicidaris are a highly sought after echinoid because of their textbook and highly detailed morphology. Their test is quite tall but almost spherical and it is covered with large, prominent tubercles. In these particular examples the oral side of the echinoid has either been lost or is still attached to matrix thus cannot be observed. They measure approximately 2 - 2.5 cm in diameter and are supplied in a small card tray with an information label.