The geodynamic evolution of the Dinaride Mountains of southeastern Europe is relatively poorly understood, especially in comparison with the neighboring Alps and Carpathians. Here, we construct a new chronostratigraphy for the post-orogenic intra-montane basins of the Central Dinarides based on paleomagnetic and 40Ar/39Ar age data. A first phase of basin formation occurred in the late Oligocene. A second phase of basin formation took place between 18 and 13 Ma, concurrent with profound extension in the neighboring Pannonian Basin. Our paleomagnetic results further indicate that the Dinarides have not experienced any significant tectonic rotation since the late Oligocene. This implies that the Dinarides were decoupled from the adjacent Adria and the Tisza–Dacia Mega-Units that both underwent major rotation during the Miocene. The Dinaride orogen must consequently have accommodated significant shortening. This is corroborated by our AMS data that indicate post-Middle Miocene shortening in the frontal zone, wrenching in the central part of the orogen, and compression in the hinterland. A review of paleomagnetic data from the Adria plate, which plays a major role in the evolution of the Dinarides as well as the Alps, constrains rotation since the Early Cretaceous to 48 ± 10° counterclockwise and indicates 20° of this rotation took place since the Miocene. It also shows that Adria behaved as an independent plate from the Late Jurassic to the Eocene. From the Eocene onwards, coupling between Adria and Africa was stronger than between Adria and Europe. Adria continued to behave as an independent plate. The amount of rotation within the Adria-Dinarides collision zone increases with age and proximity of the sampled sediments to undeformed Adria. These results significantly improve our insight in the post-orogenic evolution of the Dinarides and resolve an apparent controversy between structural geological and paleomagnetic rotation estimates for the Dinarides as well as Adria.

In the Early to Middle Miocene, a series of lakes, collectively termed the Dinaride Lake System (DLS), spread out across the north-western part of the Dinaride–Anatolian continental block. Its deposits, preserved in numerous intra-montane basins, allow a glimpse into the palaeoenvironmental, palaeobiogeographic and geodynamic evolution of the region. Lake Gacko, situated in southern Bosnia and Herzegovina, is one of the constituent lakes of the DLS, and its deposits are excellently exposed in the Gračanica open-cast coal-mine. A detailed study of the sedimentary succession that addresses facies, sediment petrography, geophysical properties, and fossil mollusc palaeoecology reveals repetitive changes in lake level. These are interpreted to reflect changes in the regional water budget. First-order chronologic constraints arise from the integration of radio-isotopic and palaeomagnetic data. 40Ar/39Ar measurements on feldspar crystals from a tephra bed in the upper part of the sedimentary succession indicate a 15.31 ± 0.16 Ma age for this level. The reversed magnetic polarity signal that characterises the larger part of the investigated section correlates to chron C5Br of the Astronomically Tuned Neogene Timescale. Guided by these chronologic data and a detailed cyclostratigraphic analysis, the observed variations in lake-level, evident as two ~ 40-m and seven ~ 10-m scale transgression–regression cycles, are tuned to ~ 400-kyr and ~ 100-kyr eccentricity cycles. From the tuning, it can be inferred that the sediments in the Gacko Basin accumulated between ~ 15.8 and ~ 15.2 Ma. The economically valuable lignite accumulations in the lower part of the succession are interpreted to indicate the development of swamp forests in conjunction with lake-level falls corresponding to ~ 100-kyr eccentricity minima. Pedogenesis, rhizoliths and palustrine carbonate breccias in the upper part of the section reveal long-term aridity coinciding with a ~ 400-kyr eccentricity minimum. Eccentricity maxima are interpreted to trigger lake-level high-stands. These are accompanied by eutrophication events caused by enhanced denudation of the surrounding basement and increased detrital input into the basin. The presented age model proves that Lake Gacko arose during the Middle Miocene Climatic Optimum and that the optimum climatic conditions triggered the formation of this long-lived lake.

The Late Miocene paleogeography of central Europe and its climatic history are well studied with a resolution of c. 106 years. Small-scale climatic variations are yet unresolved. Observing past climatic change of short periods, however, would encourage the understanding of the modern climatic system. Therefore, past climate archives require a resolution on a decadal to millennial scale.

The Dinaride Lake System, as one of the largest freshwater systems in the Neogene of Europe, is widely known for its exceptional mollusc fauna. During the Early and Middle Miocene, it displayed a major evolutionary hotspot resulting in a high level of endemicity. Despite advanced investigations in that region, comprehensive knowledge on the mollusc fauna of the Kupres basin is largely lacking. The herein presented results give insight into this outstandingly preserved fauna and are the base for a systematic revision of several supraspecific taxa among the Hydrobiidae. Because their phylogeny is poorly known, this study may serve as starting point for an overall systematic revision of this highly diverse family. Moreover, the faunal composition allows inferences on palaeobiogeography and hydrological connections within the Dinaride Lake System during the early Middle Miocene. About one-third of the described taxa are restricted to the Kupres basin. The other taxa document faunistic relations to the coeval faunas of the Sinj, Drniš and Džepi basins. Phases of hydrological isolation, indicated by carbonate dominated lithology, coincide with a high frequency of sculptured morphologies within the gastropods. Phases of increased aridity led to high evaporation, a lowered lake level and enhanced carbonate production which seem to have promoted strongly calcified shells. The stratigraphic ranges of the species imply a depositional age of 15.5 ± 0.2 Ma (earliest Middle Miocene; Langhian). Among the Hydrobiidae Cyclothyrella gen. nov. and Pseudodianella gen. nov. are introduced as new genera. Bania obliquaecostata sp. nov., Melanopsis corici sp. nov., Nematurella vrabaci sp. nov., Prososthenia diaphoros sp. nov. and Prososthenia undocostata sp. nov. are described as new species. For the secondary homonym Melanopsis bittneri (Neumayr, 1880), the new name Melanopsis medinae nom. nov. is proposed.