Late Cretaceous nautilids from northern Cantabria, Spain

Abstract

Nautilids do not occur throughout the Upper Cretaceous succession in northern Cantabria. Although relatively rare, they preferentially occur in condensed transgressive horizons. Nine species belonging to the genera Angulithes MONTFORT, 1808, Eutrephoceras HYATT, 1894, and Pseudocenoceras SPATH, 1927 are recorded. A. westphalicus (SCHLÜTER, 1872) and E. cf. justum (BLANFORD, 1861) are reported for the first time from the Iberian Peninsula. The diagnosis of A. vascogoticus WIEDMANN, 1960 is emended.The Cenomanian was characterized by a relative abundance of nautilids of the genus Angulithes which display a major radiative event, evolving relatively short-lived species. This development was probably related to the “Cenomanian transgression“. Compared to co-occurring ammonite faunas, Angulithes inhabited deeper and more distal environments. A possible transitional form, connecting the two genera Angulithes and Deltocymatoceras KUMMEL, 1956 (?Turonian, Coniacian - Santonian), is recorded from the Mid-/Late Cenomanian. The Turonian to Campanian succession is dominated by long-ranging nautilids of the genus Eutrephoceras.