The trilobite genus Prionocheilus is more known from the Czech and Portuguese Llanvirn, but it also occurs in the british ordovician. Here we offer a good example of a quite rare Prionocheilus mendax from the Llanfallteg Fm. 
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Location:  | Spittal, Pembrokeshire, Wales | ||
| Size of Trilobite: | about 23 mm long | ||
| Age: | Ordovician, Llanvirn (Darriwilian), Llanfallteg Formation (Didymograptus artus biozone) (about 455 Mill. Years) | ||