Neotrematopora tenuis, 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 : 708-710

Neotrematopora tenuis n. sp. ( Figs 10 D-G; 11A; 22E, F; Appendix)

HOLOTYPE. — SMF 21.207 .

PARATYPES. — SMF 21.208- SMF 21.211.

ETYMOLOGY. — The species name refers to the thin colony (derived from Latin “ tenuis ” = thin).

TYPE LOCALITY. — Arauz Sur (Arroyo section), Province of Palencia, NW-Spain (Cantabrian Mountains).

TYPE HORIZON. — Lebanza Formation, Lower Devonian (Pragian).

DIAGNOSIS. — Encrusting colonies; autozooecial apertures rounded-polygonal; autozooecial diaphragms common to abundant; mesozooecia common, 2-5 surrounding each aperture; acanthostyles moderately large, common to abundant, 2-5 surrounding each aperture; exozonal walls distinctly laminated, often with secondary cingulum; maculae consisting larger autozooecia present.

DESCRIPTION

Encrusting colonies, 0.47-1.11 mm in thickness. Autozooecia budding from a thin epitheca, for a short interval oriented parallel to the substrate then bending sharply and intersecting the colony surface at right angles. Autozooecial apertures roundedpolygonal. Autozooecial diaphragms common to abundant, thick, straight or slightly deflected proximally.Mesozooecia common, 2-5 surrounding each aperture, polygonal in cross section, often beaded, irregular, containing planar diaphragms. Acanthostyles moderately large, abundant, 2-5 surrounding each aperture, originating in the distal part of exozone, sometimes indenting autozooecia, having distinct calcite cores and dark laminated sheaths. Walls in endozone granular, 0.010 -0.015 mm thick; in exozone distinctly laminated; 0.03-0.08 mm thick.Cingulum often developed, 0.005 -0.025 mm thick, laminated parallel to autozooecial wall surface. Maculae consisting of larger autozooecia, 0.78-0.93 mm in diameter.

COMPARISON

Neotrematopora tenuis n. sp. is similar to N. petaloides (Astrova, 1954) from the Lower Devonian (Lochkovian) of Ukraine. The new species differs in having encrusting colony, more abundant diaphragms and less abundant acanthostyles (2-5 around each aperture vs 4-7 in N. petaloides ).

Figures

FIG. 10. — A-C, Petalosis clarus n. gen., n. sp.: A, B, autozooecial apertures with styles (arrows),paratype SMF 21.200; C, longitudinal section showing autozooecia with diaphragms and vesicles, holotype SMF 21.194;D-G, Neotrematopora tenuis n. sp.; D, E, tangential section showing autozooecial apertures and acanthostyles, holotype SMF 21.207; F, longitudinal section, holotype SMF 21.207; G, longitudinal section, paratype SMF 21.211. Scale bars: A, E, 0.2 mm; B, 0.1 mm; C, 1 mm; D, F, G, 0.5 mm.