Eridotrypella validaeformis, 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 : 712-714

Eridotrypella validaeformis n. sp. ( Figs 12 G-I; 13A-C; Appendix)

HOLOTYPE. — SMF 21.227 .

PARATYPES. — SMF 21.228- SMF 21.237.

ETYMOLOGY. — The species name refers to the similarity with the species Eridotrypella valida Duncan, 1939 . Type locality. — Arauz Sur (Arroyo section), Province of Palencia, NW-Spain (Cantabrian Mountains).

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

DIAGNOSIS. — Ramose branched colonies with narrow, distinctly separated exozones; autozooecial diaphragms rare; exilazooecia rare; acanthostyles rare to common, up to 3 surrounding autozooecial apertures; maculae with slightly larger autozooecia.

DESCRIPTION

Ramose branched colonies, branches 1.72-2.99mm in diameter. Exozones 0.36-0.72 mm wide, endozones 0.88-1.94 mm wide. Exozones distinctly separated from endozones. Secondary overgrowths occurring. Autozooecia polygonal in transverse section, long in endozones, bending sharply in exozones and intersecting colony surface at angles of 77-83°. Autozooecial apertures polygonal with rounded corners. Autozooecial diaphragms rare to common, straight, thin, occurring mainly in the distal parts of autozooecia. Exilazooecia rare, short, rounded-polygonal in cross section. Acanthostyles rare to common, up to 3 surrounding autozooecial apertures, moderately large, having distinct narrow cores and laminated sheaths. Autozooecial walls in endozones granular, locally crenulated, 0.005 - 0.010 mm thick; in exozones finely laminated, irregularly thickened, merged, containing spherules, 0.03-0.06 mm thick. Laminated cingulum locally developed, 0.005 -0.010 mm thick. Maculae consisting of slightly larger autozooecia.

COMPARISON

Eridotrypella validaeformis n.sp. differs from E.valida Duncan, 1939 from the Middle Devonian of Michigan, in having thinner branches and smaller autozooecia (autozooecial aperture widths 0.12- 0.17 mm vs 0.21-0.25 mm in E. valida ). Eridotrypella validaeformis n. sp. differs from E. minuta Morozova, 1961 from the Upper Devonian of Kuznetzk Basin, in having fewer acanthostyles and in the presence of maculae.

Figures

FIG. 12. — A-F, Leioclema multiacanthoporum (Astrova in Astrova & Yaroshinskaya, 1968): A-C, branch oblique section showing autozooecia, mesozooecia and acanthostyles,SMF 21.225; D, branch transverse section, SMF 21.221; E, longitudinal section showing autozooecia and mesozooecia, SMF 21.222; F, tangential section showing autozooecial apertures, mesozooecia and acanthostyles, SMF 21.226; G-I, Eridotrypella validaeformis n. sp.: G, branch oblique section, paratype SMF 21.385; H, longitudinal section showing autozooecia with diaphragms, holotype SMF 21.227; I, tangential section showing autozooecial apertures and rare exilazooecia, holotype SMF 21.227. Scale bars: A-C, I, 1 mm; D, G, 2 mm; E, F, 0.2 mm; H, 0.5 mm.