Article: The trilobite Protolloydolithus from the Middle Ordovician of north Portugal

Protolloydolithus sp. nov., from beds of Llandeilo age in north Portugal, is described and figured. The genus was previously unknown from Iberia, and the present record indicates faunal links with southern Britain during middle Ordovician times. The appearance of the genus is linked to a transgressive event following an early Llandeilo lowering of the sea level.