Clam shrimp fauna (Diplostraca-Spinicaudata and Estheriellina) from the Lower Cretaceous of Las Hoyas, Cuenca (Spain)

Abstract

New invertebrate records from the Lower Cretaceous Las Hoyas site (La Huérguina Formation, Iberian Range, Spain) are here described, among them, the first record of clam shrimps from this unit. This fauna includes a new afrograptid, Lahuerguinagrapta multicostata gen. et sp. nov., the eosestherioid-polygraptid Skyestheria sp., and the anthronestheriid Pseudestherites sp. This fauna is characterized by large individuals with wide growth bands, suggesting favorable paleoenvironmental conditions. Regarding preservation, according to the analysis of energy dispersive X-ray spectrometry, carapaces are preserved mainly in calcium phosphate. These new clam shrimp records represent the third report of a European afrograptid, the second finding of the genus Skyestheria in Europe and the first European record of the genus Pseudestherites and its fourth report outside China. In addition, these findings, given their restricted stratigraphic and geographical record, support the Early Cretaceous (Barremian) age of the La Huérguina Formation and confirm the importance of the Iberian region as a bridge for the dispersion of Jurassic–Cretaceous forms from the Southern Hemisphere.