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)
Author
Ernst, Andrej
Author
Fernández, Luis Pedro
Author
Fernández-Martínez, Esperanza
Author
Vera, Carmen
text
Geodiversitas
2012
2012-12-31
34
4
693
738
http://dx.doi.org/10.5252/g2012n4a1
journal article
10.5252/g2012n4a1
1638-9395
5380890
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.