Vidronovella Gorjunova, 2006

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 : 718

Genus Vidronovella Gorjunova, 2006

TYPE SPECIES. — Vidronovella fastigiata Gorjunova, 2006 , by original designation. Late Devonian (Famennian) ; Afghanistan.

OCCURRENCE. — Lower Devonian of Spain, Middle Devonian of Western Sahara and Germany, Upper Devonian of Afghanistan.

DIAGNOSIS. — Colonies branched. Autozooecia tubular, short, budding from indistinct medial axis or short mesotheca in spiral order around the branch, oriented at high angles to the branch axis. Autozooecial diaphragms absent. Proximal part of autozooecia thickened in the outermost exozone (“fastigia” sensu Gorjunova 2006). Both superior and inferior hemisepta present, located in the distal part of autozooecia. Superior hemiseptum moderately long, hook-shaped, curved distally, positioned at the base of the thicken exozone (“fastigium” sensu Gorjunova 2006); inferior hemiseptum long, slender, occupying two-thirds of body cavity of autozooecia, positioned beneath superior hemisepta, curved distally. Secondary blunt hemisepta may occur, one proximally to the superior hemiseptum, and another one distally to the inferior hemiseptum. Autozooecial apertures oval to rounded-rhombic, arranged regularly in alternating rows on the colony surface. Acanthostyles large and blunt, with narrow hyaline cores and wide laminated sheaths, embedded in the skeleton. Single or two acanthostyles positioned between two longitudinally successive autozooecial apertures. Paurostyles occur in one species, irregularly distributed between acanthostyles. Heterozooecia absent. Walls granular in the endozone; laminated in exozone, becoming structureless near the colony surface. Mural spines may occur.

COMPARISON

The genus Vidronovella Gorjunova, 2006 is placed here in the family Rhabdomesidae Vine, 1884 because of the autozooecial shape as well as the presence of hemisepta and acanthostyles. Vidronovella is similar to Orthopora Hall, 1886 , but differs from in the short autozooecia and the high budding angle of the autozooecia in the axial area.