Altshedata hispanica, 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 : 700

Altshedata hispanica n. sp. ( Figs 5 A-H; 6A-C; Appendix)

HOLOTYPE. — SMF 21.130 .

PARATYPES. — SMF 21.131- SMF 21.149.

ETYMOLOGY. — The species name refers to the finding of this species in Spain (from Latin “ hispanicus ” = Spanish).

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

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

DIAGNOSIS. — Encrusting colonies; autozooecia prismatic; autozooecial diaphragms common, straight, thin; lunaria well-developed, prominent; megazooecia occurring; vesicles occasionally present, never isolating autozooecia; communication pores absent; maculae not observed.

DESCRIPTION

Encrusting colonies, 1.0- 3.5mm thick. Autozooecia prismatic,budding from the basal epitheca,hemispherical to trapezoidal at their bases, becoming then rhombic to hexagonal, recumbent in proximal parts, then bending sharply and intersecting colony surface at right angles. Autozooecial diaphragms common, straight, thin. Autozooecial apertures rounded-polygonal. Lunaria well-developed, prominent, rounded, deeply indenting autozooecial cavity, originating from bases of autozooecia, consisting of hyaline material. Ends of lunaria curved to form almost a tube.Megazooecia occurring, 0.42-0.48 mm wide. Other heterozooecia not observed. Vesicles occasionally present, irregular in shape and size, concentrated at base of exozone, never isolating autozooecia. Autozooecial walls in the endozone granular, straight, 0.005 -0.010 mm thick; in exozone irregularly thickened, showing indistinct granular microstructure, 0.04-0.07 mm thick.True communication pores not observed, but deep annulations in walls giving false appearance of communication pores. Maculae not observed.

COMPARISON

Altchedata hispanica differs from the type species A. belgebaschensis (Nekhoroshev, 1948) in having fewer vesicles, smaller autozooecial apertures (autozooecial width 0.23-0.38 vs 0.40 mm in A. belgebaschensis ) and larger lunaria. Altchedata hispanica differs from Altchedata gracilis in its larger autozooecia (average autozooecial width 0.3 mm vs 0.27 mm in A. gracilis ), presence of megazooecia and absence of style-like projections in the autozooecial walls.

Figures

FIG. 5.— Altshedata hispanica n.sp.: A-C, longitudinal section showing autozooecia with abundant diaphragms,holotype SMF 21.130; D, longitudinal section showing microstructure of autozooecial walls, paratype SMF 21.142; E, F, tangential section showing autozooecial apertures and lunaria, holotype SMF 21.130; G, H, deep tangential section of autozooecial chambers, paratype SMF 21.142. Scale bars: A-C, 1 mm; D, 0.1 mm; E, G, 0.5 mm; F, H, 0.2 mm.