ABSTRACT
Earliest Jurassic brachiopods are only sporadically known from the Transdanubian Central Range (Hungary). Bed-by-bed collections have been made at 16 localities in the Bakony and Gerecse Mountains, which yielded 14 brachiopod species from the Hettangian and 64 species from the Lower Sinemurian. Twelve species are recorded for the first time from Hungary and the stratigraphic ranges of another 44 species are amended for the study area. The global stratigraphic ranges of 14 species are updated: these species appeared earlier in the Transdanubian Central Range than elsewhere. After the end-Triassic mass extinction, the diversity of the brachiopod fauna did not increase as evenly from the Hettangian to the Pliensbachian as was previously thought. A rapid and sudden diversification happened in the Hettangian and Early Sinemurian. Nine genera were already present in the Hettangian and 22 genera were represented in the earliest Sinemurian Bucklandi Zone. The maximum diversity of the Early Jurassic brachiopod fauna was already reached by the Sinemurian.
