Alfréd Dulai

A fossil record full of holes: The Phanerozoic history of drilling predation

The evolutionary history of drilling predation, despite a long and rich fossil record (Precambrian–Holocene), contains a 120 m.y. gap (Late Triassic–Early Cretaceous). Drilled bivalve and brachiopod shells from Jurassic deposits of Hungary, India, and four localities documented in the literature indicate that drillers may have existed continuously throughout the Mesozoic. They may have been descendants of Paleozoic predators, unknown Mesozoic carnivores, or precursors of modern drillers. A literature database suggests three major phases in the Phanerozoic history of drilling predators: (1) the Paleozoic phase (latest Precambrian–Carboniferous) dominated by rare to moderately frequent drillings in brachiopods and sessile echinoderms; (2) the Mesozoic phase (Permian–Early Cretaceous) with very rare, or even facultative, drillers that had little impact on marine benthic communities, but nevertheless may have been present continuously; and (3) the Cenozoic phase (Late Cretaceous –Holocene) dominated by frequent gastropod drillings in mollusks.

Coral microbialite environment in a Middle Miocene reef of Hungary

Abstract The presence of microbial crusts (microbialites) is reported here for the first time from a Middle Miocene (Badenian) coral reef in Hungary. The succession of initiation and development of the microbial crusts is described in relation to the reef architecture. The main features of the palaeoenvironment are discussed, with focus on the associated invertebrate faunas, mostly corals, molluscs, bryozoans, and crabs. We conclude that the microbial crusts developed under normal marine conditions and were a significant contributor to reef framework development, including its strengthening through calcification of the microbial organisms. Microbialites are anticipated in other Early and Middle Miocene coral reef occurrences of the Mediterranean–Paratethys realm, and to date may have simply escaped positive recognition.

First glimpse into Lower Jurassic deep-sea biodiversity: in situ diversification and resilience against extinction

Owing to the assumed lack of deep-sea macrofossils older than the Late Cretaceous, very little is known about the geological history of deep-sea communities, and most inference-based hypotheses argue for repeated recolonizations of the deep sea from shelf habitats following major palaeoceanographic perturbations. We present a fossil deep-sea assemblage of echinoderms, gastropods, brachiopods and ostracods, from the Early Jurassic of the Glasenbach Gorge, Austria, which includes the oldest known representatives of a number of extant deep-sea groups, and thus implies that in situ diversification, in contrast to immigration from shelf habitats, played a much greater role in shaping modern deep-sea biodiversity than previously thought. A comparison with coeval shelf assemblages reveals that, at least in some of the analysed groups, significantly more extant families/superfamilies have endured in the deep sea since the Early Jurassic than in the shelf seas, which suggests that deep-sea biota are more resilient against extinction than shallow-water ones. In addition, a number of extant deep-sea families/superfamilies found in the Glasenbach assemblage lack post-Jurassic shelf occurrences, implying that if there was a complete extinction of the deep-sea fauna followed by replacement from the shelf, it must have happened before the Late Jurassic.

Brachiopod assemblages from the Early-Middle Jurassic transition in the Eastern Subbetic (SE Spain): Systematic and palaeobiogeographic implications and palaeoenvironmental significance

This research has been supported by the Synthesys Project (HU-TAF 3036) of the European Union and the Project CGL2009-07830 of MCI (Spain). A. Dulai was supported by the Hungarian Scientific Research Fund (OTKA K77451).

New paleobiogeographical and paleoenvironmental insight through the Tortonian brachiopod and ichnofauna assemblages from the Mediterranean-Atlantic seaway (Guadix Basin, SE Spain)

The paleogeography of the Late Neogene Atlantic-Mediterranean seaway via the Betic-Rifean Domain is quite complex due to the presence of several marine corridors. The study of transitional basins in these seaways is crucial to understand the configuration and evolution of the Mediterranean-Atlantic inter-connection. A mixed skeletal-siliciclastic sandstone succession located in one of these transitional areas (Guadix Basin, Southern Spain) was studied from a comprehensive paleontological standpoint focused on the main benthic assemblages (foraminifera, brachiopods, and trace fossils), integrating the data with the study of planktic foraminifera for an accurate biostratigraphic framework. Brachiopods are mostly represented by the Aphelesia-Gryphus assemblage. Two trace fossil assemblages were observed, dominated by Ophiomorpha with Bichordites (1) and Macaronichnus (2), respectively. The benthic foraminiferal assemblage is mostly represented by Planulina and Cibicides. The data gathered from the benthic communities reveal habitats with high-energy and turbulent conditions in an outer neritic-upper bathyal bathymetric range. Brachiopods from the Alicún section show a Mediterranean paleobiogeographic affinity. They were constrained in the Late Tortonian to the restricted basins of the Betic-Rifean Seaway and after the Messinian Salinity Crisis proliferated in both Mediterranean- and Atlantic-type basins of the Betic-Rifean Domain. The Guadix Basin contributed to the Mediterranean-Atlantic faunal inter-connection through the Betic-Rifean Seaway during the Late Tortonian and facilitated the earliest Pliocene expansion of brachiopods in the Mediterranean.