The last non-avian theropods of Europe: Palaeoecology and biogeography inferred from dental records from the uppermost Maastrichtian of Catalonia, Spain

Abstract

Non-avian theropods were essential components of terrestrial ecosystems during the Mesozoic, were highly diverse in size and lifestyles across different regions of the planet. Here we assess the composition and diversity of the theropod fauna of the Ibero-Armorican island (the ancient region that encompassed present-day areas of Spain, Portugal, and France) during the final few hundred thousand years of the Cretaceous, by reviewing the theropod teeth assemblage from the locality of Molí del Baró-1 (upper Maastrichtian, C29r, Catalonia, Spain). Our study indicates a diverse fauna of small non-avian theropods with different feeding strategies and ecological niches. The tooth assemblage is significantly more diverse than previously thought and includes dental elements referred to dromaeosaurines, velociraptorines, troodontids, and an undetermined Dromaeosauridae tooth with similarities to microraptorines, as well as previously-referred teeth of cf. ?Richardoestesia and aff. Paronychodon. Microwear analysis reveals diverse feeding styles among these theropods, and particularly indicates that the troodontid had an omnivorous diet heavy in plant consumption. The assemblage of small-sized non-avian theropods and medium-to large-sized abelisaurids from the uppermost Maastrichtian of Ibero-Armorica differs from others from the European archipelago and worldwide, illustrating the high regional variability of theropod faunas around the time the asteroid impact ended the Cretaceous.