of large Monotis bivalves and the disappearance of ammonoids including Metasibirites and some Sagenites forms with lateral nodes. A second formal GSSP candidate was not provided until Rigo et al. (2015) proposed the Pignola-Abriola section of southern Italy. This is a sequence of the Norian-Rhaetian Calcari con Selce ("Cherty limestone") Formation named after two nearby towns. It preserves a diverse array of conodonts (including the Misikella hernsteini-posthernsteini morphocline) as well as pronounced radiolarian zones. Rhaetian-Hettangian boundary The top of the Rhaetian (the base of the Hettangian Stage, the Lower Jurassic Series and the Jurassic System) is at the first appearance of ammonite genus Psiloceras. In the Tethyan domain, the Rhaetian contains two ammonite biozones. The highest ammonite biozone is that of Choristoceras marshi, the lower one that of Rhabdoceras suesii. The end of this period is marked by the Triassic-Jurassic extinction event. The GSSP marking the beginning of the Hettangian (and the end of the Rhaetian) is located at Kuhjoch, a geological section near the base of the Kendelbach Formation in Austria. This site records the first appearance of Psiloceras spelae, Cerebropollenites thiergartii (a palynomorph), Praegubkinella turgescens (a foraminifer), Cytherelloidea buisensis (an ostracod), and a positive δ13C spike marking a recovery from the underlying large negative δ13C spike which marks the Triassic-Jurassic extinction event. Duration Norian-Rhaetian boundary: "short Rhaetian" hypotheses Gallet et al. (2007) argued in support of a "short Rhaetian" (where the Rhaetian lasts under 5 million years) based on the Oyuklu section, a sequence from Turkey. This sequence was largely normal-polarity dominated, and presented two potential Norian-Rhaetian boundaries (since the defining biostratigraphy of the Rhaetian was not resolved at the time). Defining the boundary based on the appearance of Misikella posthernsteini placed it in a reverse-polarity section (B-) near the base of Oyuklu. Defining the boundary based on the extinction of Epigondolella bidentata placed it at magnetozone G+, the first of several major normal-polarity sections. The early reverse-polarity zones (B- to D-) were correlated with PM11r, a reverse-polarity section at the top of Pizzo Mondello, a similar Carnian-Norian sequence in Sicily. The inferred overlap between these reverse-polarity sections was located above a normal-polarity section (A+ in Oyuklu and PM11n in Pizzo Mondello). This underlying normal-polarity section was correlated with either magnetozone E21n or E23n of the Newark sequence. Although the upper portion of Oyuklu was mostly normal, it did have a few reverse sections (H- and J-) which