Double-armoured herrings (Clupeomorpha: Ellimmichthyiformes) from the Lower Cretaceous of Pietraroja (Southern Italy)

The Lower Cretaceous (Albian) clupeomorph fishes of the Pietraroja Plattenkalk were among the first fishes described for this celebrated Italian Konservat-Lagerstatte. However, a detailed anatomical and phylogenetic study has never been carried out on these fishes in order to clarify their taxonomic status, systematic position, and relationships within the Clupeomorpha. The specimens examined herein exhibit diagnostic features that clearly support their alignment with the extinct double-armoured herring order Ellimmichthyiformes. Based on the presence of an incomplete series of heart-shaped predorsal scutes, a new combination, Armigatus elatus (Costa, 1850), and the new species Armigatus plinii sp. nov. are recognized as the oldest representatives of the family Armigatidae, whereas a unique combination of features allows us to recognize most of the specimens as a new representative of the family Paraclupeidae, Paraclupea pietrarojae sp. nov. The presence of lower Albian species of Armigatus and Paraclupea in the Western Tethys extends the temporal and biogeographical range of these widely distributed genera, providing additional information for our understanding of the evolutionary and biogeographical history of the double-armoured herrings.