First report of Sclerobiont Bryozoans in the Maiolica Fm. of the Umbria-Marche Basin (Northern Apennines, Italy)

ANGELO CIPRIANI; SIMONE FABBI; MARCO ROMANO; PAOLO CITTON

Rendiconti Online della Società Geologica Italiana

Società Geologica Italiana

Lugar: Roma; Año: 2019 vol. 48 p. 106 - 111

We describe the first evidence of sclerobiont bryozoans foundloose in the pelagic Maiolica Fm. of the Umbria-Marche Basin (MonteAcuto Massif, Northern Apennines, Italy). The material is representedby three small sub-circular colonies with tube-shaped zooecia radiallydeveloping from the centre. These characters are not enough forgeneric or specific classification, consequently, these cyclostomeshave been only identified as belonging to the Suborder Tubuliporina.Calpionellid assemblages allow to constrain the bryozoan-bearing rocksample to the early Berriasian. The occurrence of isolated bryozoansin the Maiolica Fm. enriches the knowledge about the fauna of thisunit in pure basinal settings, composed by radiolarians, calpionellids,dinoflagellate cysts and rare macrofossils (ammonites and aptychi),including very rare benthic organisms (gastropods, brachiopods andbivalves). Up to date, no sclerobiont organisms in ?normal? pelagicMaiolica facies were known, due to the lack of suitable substrates tobe colonised. Encrustation of a planktonic or nektonic hard-shelledorganism seems the most parsimonious hypothesis based on ourmaterial.