Possible remains of the digestive system of several Upper Ordovician trilobites are described and shortly discussed. They belongs to the trilobite genera Selenopeltis, Dalmanitina, Deanaspis and Birmanites.
The remains represent a specific type of preservation in the medium-grained sandstones of the Letná Formation. They represent a unique Lagerstatten comparable with the best localities worldwide (e.g Morocco).