| Here is a good example Ectillaenus katzeri in a nice Rokycany concretion from the Šárka Formation. | |||
| Location: | Rokycany , Barrandian area, Czech Republic | ||
| Size trilobite: | 47 mm long | ||
| Age: | Middle Ordovician, Llandeilo, Šárka Formation (About 464 mill. Years old) | ||