Early Devonian non-trilobite arthropods from the Iberian Chains (North East, Spain)

Slightly sclerotised arthropods are described from shales of the Early Devonian age of the Axial Depression of the Cámaras river in Northeast Spain. The oldest records represent eurypterid fragments assigned to indeterminate Pterygotidae. They have been found in the early Pragian Nogueras Formation associated with land plant remains and rare marine invertebrates. The other two correspond to the first report of the phyllocarid Nahecaris in Spain. Nahecaris carlsi n. sp. is represented by a single complete specimen from the Pragian Santa Cruz Formation and Nahecaris sp. by another specimen from the Emsian Mariposas Formation. Both are associated with a rich marine fauna of various invertebrate groups. Environmentally, these arthropods occupied different areas from marginal marine (Pterygotidae indet.) to more open marine conditions (Nahecaris). The discovery of slightly sclerotised arthropods in several levels informs about the potential of the area for such type of preservation.