Fragmenta Palaeontologica Hungarica

Author(s): Dulai, A.
Title: Badenian (Middle miocene) micromorphic brachiopods from Bánd and Devecser (Bakony mountains, Hungary)
Year: 2007
Volume: 24-25
Pages: 1-13.

Abstract: The described brachiopod assemblage (427 specimens from the Lower Badenian shallow water deposits of the Bakony Mts) comprises 3 micromorphic species belonging to two genera of Megathyrididae. Argyrotheca cordata and A. cuneata are relatively common members of the coral-bearing, diverse fauna at Bánd. The very limited Devecser material yielded isolated but well-preserved A. cordata and Megathiris detruncata valves. All the three species are widespread in the Miocene of the Central Paratethys, as well as in the Recent seas. The Bánd assemblage is more or less autochthonous while the Devecser brachiopods suggest only short transportation. The two Argyrotheca species show bell-shaped size-frequency distribution indicating low juvenile mortality. Protected, cryptic environments among coral branches and under boulders resulted in the unimodal, bell-shaped size distribution, indicating a stable community. Epifaunal encrusters (Bryozoa, serpulid Polychaetes) are recorded for the first time on micromorphic brachiopods in the Central Paratethys. The situation of epibionts suggests that they encrusted the ventral valves during the life of brachiopods. The serpulid probably benefits from the feeding currents of the brachiopod. Few brachiopod specimens (3.5%) show drill holes of predatory* gastropods. No taxon selectivity can be observed, but A. cuneata shows valve and site selectivity.
Keywords: Hungary, Central Paratethys, Middle Miocene, Badenian, Brachiopoda, Argyrotheca, Megathiris, size-frequency distribution, drilling predation, encrustation

Journal: Fragmenta Palaeontologica Hungarica
Journal abbreviation: Fragm. Palaeont. Hung.
ISSN: 1586-930X
Publisher: Hungarian Natural History Museum, Budapest
Editor(s): Szabó, J. & Matskási, I.