Dybowskiella piriforme, Ernst & Wyse Jackson & Aretz, 2015

Ernst, Andrej, Wyse Jackson, Patrick N. & Aretz, Markus, 2015, Bryozoan fauna from the Mississippian (Visean) of Roque Redonde (Montagne Noire, southern France), Geodiversitas 37 (2), pp. 151-213 : 160-162

Dybowskiella piriforme n. sp.

( Figs 9 D-F; 10A-D; Appendix)

ETYMOLOGY. — The species name refers to the pear-shaped apertures of this species.

HOLOTYPE. — SMF 21.781 .

PARATYPES. — SMF 21.782- SMF 21.793, TCD.60336.

TYPE LOCALITY. — Roque Redonde (Montagne Noire, southern France).

TYPE HORIZON. — Carboniferous, Mississippian (upper Visean).

DIAGNOSIS. — Colony in form of hemispheric or globular masses; apertures small, with well-developed long lunaria; lunaria with 3-5 styles; basal diaphragms absent; vesicles small to large, separating autozooecia in a single row, 5-9 surrounding each autozooecia aperture. DESCRIPTION

Encrusting colony forming usually hemispheric to globular masses, 0.9-1.5 mm thick. Autozooecia growing from thin epitheca, often for long distances parallel to substrate, bending in the early exozone to the colony surface. Basal diaphragms absent. Autozooecial apertures circular to oval. Lunaria large, long, thick, containing 3-5 styles; lunarial styles 0.010 -0.015 mm in diameter; ends of lunaria indenting autozooecia. Vesicles small to large, separating autozooecia in a single row, 5-9 surrounding each autozooecia aperture, with rounded to flat roofs, polygonal in tangential section. Autozooecial walls granular prismatic, 0.005 -0.010 mm thick.

COMPARISON

Dybowskiella piriforme n. sp. differs from D. lebedevi Nikiforova, 1927 from the Lower Carboniferous of Ukraine in smaller autozooecial apertures (0.17-0.25 mm vs 0.30-0.35 mm in D. lebedevi ). Furthermore, Fistulipora elegans Schulga-Nesterenko, 1955 from the Moscovian of the Russian Platform is similar to the present species. However, F. elegans has larger und thicker lunaria.

Figures

FIG. 9. — A-C, Dybowskiella rotunda n. sp.; A, tangential section, holotype SMF 21.777; B, tangential section, paratype SMF 21.780; C, longitudinal section, holotype SMF 21.777. D-F, Dybowskiella piriforme n. sp., holotype SMF 21.781: D, tangential section, E, F, tangential section showing autozooecial aperture with lunarium. Scale bars: A, B, D, 0.5 mm; C, 2 mm; E, 0.2 mm; F, 0.1 mm.