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The development of high‐resolution 3D seismic cubes has permitted recognition of variable subvolcanic features mostly located in passive continental margins. Our study area is situated in a different tectonic setting, in the extensional Pannonian Basin system (central Europe) where the lithospheric extension was associated with a wide variety of magmatic suites during the Miocene. Our primary objective is to map the buried magmatic bodies, to better understand the temporal and spatial variation in the style of magmatism and emplacement mechanism within the first order Mid‐Hungarian Fault Zone (MHFZ) along which the substantial Miocene displacement took place. The combination of seismic, borehole and log data interpretation enabled us to delineate various previously unknown subvolcanic‐volcanic features. In addition, a new approach of neural network analysis on log data was applied to detect and quantitatively characterise hydrothermal mounds that are hard to interpret solely from seismic data. The volcanic activity started in the Middle Miocene and induced the development of extrusive volcanic mounds south of the NE‐SW trending, continuous strike‐slip fault zone (Hajdú Fault Zone). In the earliest Late Miocene (11.6–9.78 Ma), the style of magmatic activity changed resulting in emplacement of intrusions and development of hydrothermal mounds. Sill emplacement occurred from south‐east to north‐west based on primary flow‐emplacement structures. The time of sill emplacement and the development of hydrothermal mounds can be bracketed by onlapped forced folds and mounds. This time coincided with the acceleration of sedimentation producing poorly consolidated, water‐saturated sediments preventing magma from flowing to the paleosurface. The change in extensional direction resulted in change in fault pattern, thus the formerly continuous basin‐bounding strike‐slip fault became segmented which could facilitate the magma flow toward the basin centre. [ABSTRACT FROM AUTHOR]

The biota of the brackish-water Lake Pannon in the Pannonian Basin is characterised by remarkable endemism due to the isolated evolution of the lake for 8 myr after the last Miocene marine connection ceased (∼11.6 Ma). A conspicuous feature of this endemism is the large, probably ecophenotypic variation in the morphology of brackish-water dinoflagellate cysts that challenges taxonomy and complicates biostratigraphical and ecological interpretations. We conclude that a widely debated Lake Pannon genus, Pontiadinium, includes several proximate dinoflagellate cyst species with prominent apical and antapical protuberances, and we show how the genus differs from the morphologically similar gonyaulacacean cyst genera Impagidinium, Leptodinium, Cribroperidinium and Komewuia. The generic description of Pontiadinium is emended together with the species descriptions of Pontiadinium inequicornutum, Pontiadinium obesum and Pontiadinium pecsvaradanesis. A new species is described as Pontiadinium szentaiae sp. nov. from Našice (northern Croatia) that is characterised by unique trabeculate sutural septa formed from a beaded tegillum supported by columellae or rod-like luxuriae. The dinoflagellate cyst assemblages of the long-lived brackish-water Lake Pannon clearly demonstrate that dinoflagellate cysts in low-salinity, isolated epicontinental seas display greater morphological plasticity than their normal-marine relatives. The development of an antapical horn appears to be a previously undocumented example of phenotypic morphological features that developed in response to subnormal salinities within at least two dinoflagellate cyst genera endemic to Lake Pannon and the Post-Paratethyan seas of the Ponto-Caspian realm. This ecophenotypic variation resulted in a higher level of morphological adaptation, leading to the evolutionary development of new dinoflagellate cyst species and genera. [ABSTRACT FROM AUTHOR]