Rhomboporidae, Simpson, 1895

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 : 720

Rhomboporidae sp. indet. ( Figs 16 C-I; Appendix)

MATERIAL. — SMF 21.313- SMF 21.314.

DESCRIPTION

Branches 0.78-0.81 mm in diameter, with 0.23- 0.26 mm wide endozones and 0.25-0.30 mm wide exozones. Branch bifurcation not observed. Autozooecia short, growing in spiral pattern from the distinct median axis. Autozooecial diaphragms locally present, thin, curved. Hemisepta absent. Autozooecial apertures oval, arranged regularly in alternating rows on the colony surface. Walls in the endozone granular, 0.015 -0.020 mm thick; laminated in exozone. Acanthostyles absent. Paurostyles abundant, scattered between apertures. Aktinotostyles irregularly distributed. Metazooecia present, usually one between two longitudinally successive autozooecial apertures.

COMPARISON

This species shows similarities to the family Rhomboporidae Simpson, 1895 in the presence of aktinotostyles and paurostyles and in autozooecial shape. However, metazooecia are rare in all genera of Rhomboporidae . The present material differs from Rhombopora Meek, 1872 in lacking acanthostyles and in the regular presence of metazooecia, and from Saffordotaxis in the presence of metazooecia and paurostyles (aktinotostyles are the only styles present in Saffordotaxis ).

Order FENESTRATA Astrova & Morozova, 1956 Suborder FENESTELLINA Astrova & Morozova, 1956 Family FENESTELLIDAE King, 1849

Figures

FIG. 16. — A, B, Vidronovella elegantula n. sp., longitudinal section showing autozooecia with long hemisepta, paratype SMF 21.296. C-I, Rhabdomesid sp. indet.; C, longitudinal section showing autozooecia, SMF 21.314; D, tangential section showing autozooecial apertures and paurostyles, SMF 21.314; E, F, longitudinal section showing autozooecia and a metazooecium (arrow), SMF 21.314; G, H, tangential section showing autozooecial apertures, aktinotostyles and paurostyles, SMF 21.313;I, longitudinal section showing aktinotostyles, SMF 21.313. Scale bars: A, B, I, H, 0.2 mm; C-F, G, 0.5 mm.