Fourteen symposia on early/lower vertebrates have taken place over the last 50 years, usually at about four year

intervals. An average 60 participants have taken part at these symposia, with over one hundred occasionally. The

results of the symposia have been published in proceedings. The symposia started honoring E. A:son Stensiö and

E. Jarvik. Honors were taken up at the 11th symposium in Uppsala again. Since the 13th symposium a Stensiö

award is also given to young researchers in the field.

The organodetritic, sandy limestones of the Treskelodden Formation (Late Gzhelian to Early Artinskian) investigated in outcrops at Treskelen Peninsula, Hyrnefjellet mount and Polakkfjellet mount of south Spitsbergen, contain rich foraminiferal assemblages. Fifty eight foraminiferal species of twenty three genera, including two new species (Hemigordius hyrnefjelleti sp. nov. and Midiella arctica sp. nov.) have been identified. Three foraminiferal zones have been defined, with ages of Late Asselian (Pseudofusulinella occidentalis), Sakmarian (Midiella ovata – Calcitornella heathi) and Early Artinskian (Hemigordius hyrnefjelleti – Midiella arctica). Sedimentary features and the biotic history of the studied succession records a Late Paleozoic cooling trend that stays in accordance with Pangaea’s shift to the north.

In the Balkans, the Serbo-Macedonian Unit (SMU), Serbia, is thrust bounded by the composite Tethyan Vardar Zone and the Carpatho-Balkanides. The SMU actually emerges from beneath the Neoalpine Miocene–Pliocene deposits. Both provenance and geodynamic position of the SMU are poorly known and still debated. This paper reviews the data hitherto published and includes some new field data interpretations. The SMU is composed of a Neoproterozoic–Cambrian high-grade (para- and ortho-) gneiss with peraluminous magmatic arc components (560–470 Ma). The SMU is in the contact with Neoproterozoic upper Ordovician–Carboniferous low-grade metasedimentary succession of an accretionary wedge assembly represented by the Supragetic basement. The SMU basement became folded, sheared and metamorphosed around 490–450 Ma. Paleomagnetic data point to high southern latitudes and a peri-Gondwanan position of the SMU at that time, which concurs with glaciomarine evidence recorded from the upper Ordovician sediments at the base of an accretionary wedge succession. Based on the published data and field survey in the Stalać region, we correlate the SMU with the pre-Mesozoic gneiss terrane exposed in the Strona-Ceneri zone of the Alps. This terrane, identified as the Cenerian orogen of the Alaskan subduction type, developed at an active margin of Gondwana during middle Ordovician times. The SMU basement, with augen and migmatitic gneisses and arc-related peraluminous magmatic bodies, developed at this margin as part of the Cenerian belt or its equivalent. Such an orogenic edifice proved transient and in the earliest Silurian the SMU fragments drifted away being bound for Baltica (amalgamated Moesian microplate and Danubian terrane) to which they became accreted in the Carboniferous and included in the southern European branch of the Variscan orogen (Marginal Dacides/Carpatho-Balkanides). Despite considerable Variscan and Alpine reworking, the pre-Variscan, Cenerian-type crustal assembly along with an inferred boundary between the magmatic arc and the accretionary wedge, accompanied by back-arc/forearc deposits, are still decipherable in the Western Balkan countries.