After the disaster: Bony fish remains (mostly otoliths) from the K/Pg boundary section at Stevns Klint, Denmark, reveal consistency with teleost faunas from later Danian and Selandian strata.

Abstract

This is the first study of bony fish remains across the K/Pg boundary section at Stevns Klint, Denmark. The studied specimens comprise one partly preserved articulated skeleton, a few isolated bones, and casts from several otolith imprints and voids. As otoliths are aragonitic, the remains are all dissolved. The imprints of the otoliths originate from the uppermost Maastrichtian Højerup Member or ‘Grey Chalk’, and the bone fragments and the partial skeleton were obtained from the Fiskeler Member directly above the K/Pg boundary. Further otolith imprints originated from the basal Danian Cerithium Limestone Member, which directly overlies the Fiskeler Member. Six otolith-based taxa were identified from the uppermost Maastrichtian and three from the basal Danian. One of the species found in the uppermost Maastrichtian persisted into Danian times (Polymixia? harderi), a second represents a common genus in both Maastrichtian and Danian but cannot be identified to the species level (Centroberyx sp.), and a third taxon is an unidentifiable dynematichthyid, which, however, certainly does not belong to any of the known Danian dinematichthyid species. The species recognised in the basal Danian all persisted well into later Danian times or even the Selandian, showing a remarkable consistency of the early Paleocene bony fish fauna. We find no indication of phased extinction in the aftermath of the K/Pg boundary event in the data recovered from the Danian.