datum of Misikella posthernsteini (sensu lato). At Steinbergkogel, M. hernsteini first occurred at the top of a normal-polarity section while M. posthernsteini (sensu lato) first appeared at the base of a shorter overlying reverse-polarity section. These sections were correlated with magnetozones E16n and E16r of the Newark Basin. Hüsing et al. (2011) preferred to define the Rhaetian based on M. hernsteini, and estimated a date for the Norian-Rhaetian boundary of 209.8 Ma based on that of Newark's magnetozone E16n. However, the ICS Triassic subcommission had already voted in 2010 to certify the first appearance of M. posthernsteini as the defining event for the base of the Rhaetian. Partially inspired by the work of Hüsing et al. (2011), the ICS's 2012 Geologic Time Scale utilized a tentative 208.5 Ma date for the Norian-Rhaetian boundary. This date has been retained in ICS time scales as of 2020. Norian-Rhaetian boundary: Recent compromises The Norian-Rhaetian boundary was finally provided with radiometric dating in a study by Wotzlaw et al. (2014). They studied a sequence of the Aramachay Formation in Peru which records the extinction of large Monotis bivalves. This prominent biotic event is closely associated with the Norian-Rhaetian boundary. The last Monotis specimens lie between ash beds which are Uranium-Lead dated to 205.70 ± 0.15 Ma and 205.30 ± 0.14 Ma. This allowed them to conclude that the Norian-Rhaetian boundary occurred somewhere between these ash beds, 205.50 ± 0.35 Ma. This date corresponds to "short-Rhaetian" predictions, but Wotzlaw et al. (2014) also agreed with "long-Rhaetian" proponents who argued that there was no good evidence for a hiatus in the Newark Basin sequence. Wotzlaw et al. (2014) estimated that the Norian-Rhaetian boundary was concurrent with a lengthy reverse polarity section (E20r.2r) of Newark magnetozone E20. Golding et al. (2016) utilized U-Pb dating at a part of the Black Bear Ridge section of British Columbia which is considered early Rhaetian based on its conodont fauna. Their estimated 205.2 ± 0.9 Ma date for this early Rhaetian section agrees with the results of Wotzlaw et al. (2014). This compromise between "short-Rhaetian" and "long-Rhaetian" hypotheses has been supported by other studies. Maron et al. (2015) elaborated on the dating of an upcoming GSSP candidate for the Rhaetian in the form of the Pignola-Abriola section in Southern Italy. This section recorded the Norian-Rhaetian boundary as tracked by the first occurrence of Misikella posthernsteini, the base of the Proparvicingula moniliformis