Petalosis, Ernst & Fernández & Fernández-Martínez & Vera, 2012

Ernst, Andrej, Fernández, Luis Pedro, Fernández-Martínez, Esperanza & Vera, Carmen, 2012, Description of a bryozoan fauna from mud mounds of the Lebanza Formation (Lower Devonian) in the Arauz area (Pisuerga-Carrión Province, Cantabrian Zone, NW Spain), Geodiversitas 34 (4), pp. 693-738 : 706-708

Petalosis n. gen.

ETYMOLOGY. — The genus name refers to the petaloid shape of autozooecial apertures due to spine-like indentions.

TYPE SPECIES. — Petalosis clarus n. sp. Lebanza Formation , Lower Devonian (Pragian) ; Arauz Sur (Arroyo section), Province of Palencia , NW-Spain (Cantabrian Mountains) .

DIAGNOSIS. — Encrusting colonies with secondary overgrowths; autozooecial apertures circular to oval; autozooecia growing from thick epitheca, bending sharply at their bases towards colony surface; basal diaphragms common to abundant; lunaria well developed, prominent, horseshoe shaped to triangular, containing 2-3 styles; one or two pairs of spine-like indentions in lateral parts of proximal ends of autozooecia; vesicles large and high, irregularly shaped, polygonal in tangential section, box-like to hemispherical, with plane or concave roofs; bands of large and irregularly shaped vesicles occurring; acanthostyles between autozooecial apertures; autozooecial walls granular in endozones and laminated in exozones; maculae not observed.

COMPARISON

Petalosis n. gen. differs from Fistuliporella Simpson, 1895 in having spine-like indentions in autozooecial apertures.