In this contribution we examine and discuss recently published magnetostratigraphic data from the Nordvik section (north Siberia) around the Tithonian–Berriasian (J/K) boundary, with a special emphasis on calibration with biostratigraphy and the reliability of both the fossil and magnetic records, as well as sedimentation rates. Specifically, we discuss original new interpretations by Bragin et al. (2013) and the commentary on that work by Guzhikov (2013). We consider some limitations of the Nordvik section, and conclude that the base of M18r, because it is in a condensed part of the sequence, makes a poor contender for precise long-range correlation. We discuss the lack of ammonites at several magnetozone boundaries, and whether the bases of the local zones of Craspedites taimyrensis and Arctoteuthis tehamaensis can be used to bracket the correlative horizon of .i>Calpionella alpina, a widespread marker in the middle of M19n.2n in Tethys.