Rectifying a substantial biostratigraphic error:There are no Hauterivian calpionellids in Busot (Alicante, Spain)

Abstract

Earlier misidentifications of ammonites from Busot (SE Spain) led to two incorrect hypotheses regarding calpionellids, which are today attributed to the Calpionellopsis Zone (D) of the upper Berriasian. The first hypothesis suggested that some calpionellid species survived into Hauterivian times, while the second hypothesis proposed that these calpionellids were reworked into Hauterivian strata. However, the revision of the ammonitic material collected in 1993-1994, along with the study of new material collected in 2024, suggests a late Berriasian age, as the ammonite assemblages likely correspond to the Fauriella boissieri and Tirnovella alpillensis Standard Ammonites zones. Nannofossil assemblages and the presence of Octahedronoides tethysianus further support this dating. This reassessment calls for a reexamination of claims regarding the occurrence of calpionellids in strata younger than the Valanginian in the literature.