Umbonulidae CANU, 1904

ZÁGORŠEK, KAMIL, 2010, BRYOZOA FROM THE LANGHIAN (MIOCENE) OF THE CZECH REPUBLIC PART II: SYSTEMATIC DESCRIPTION OF THE SUBORDER ASCOPHORA LEVINSEN, 1909 AND PALEOECOLOGICAL RECONSTRUCTION OF THE STUDIED PALEOENVIRONMENT, Acta Musei Nationalis Pragae Series B 66 (3 - 4), pp. 139-255 : 139-255

Family Umbonulidae CANU, 1904 Genus Umbonula HINCKS, 1847

Colony is encrusting or erect. Frontal wall convex, centrally imperforate with marginal areolar pores only. Suboral, medial avicularium is situated at the top of the umbo. Oral avicularia may also be present. Oral spines and lyrula absent. Ovicell globular with a perforate frontal wall.

Umbonula macrocheila ( REUSS, 1847) Pl. 92, Fig. 1-6 v.* 1847 Eschara macrocheila m. – Reuss p. 65, Pl. 8, Fig. 14

v. 1989 Umbonula macrocheila ( REUSS, 1847) – Schmid p. 31, Pl. 8, Fig. 1-4 (cum syn.)

1997 Umbonula macrocheila ( REUSS, 1847) – Pouyet p. 50, Pl. 4, fig. 10 and Pl. 5, Fig. 5 (cum syn.)

2003 Umbonula macrocheila ( REUSS, 1847) – Zágoršek p. 160, Pl. 23, Fig. 5 (cum syn.)

T y p e: Holotype stored in the Natural History Museum Vienna under the number 1847.38.56 (confirmed by David and Pouyet, 1974).

M a t e r i a l: More than 100 specimens from all the studied sections were examined.

D i a g n o s i s: Colony encrusting. Autozooecia oval with convex, smooth frontal wall, characteristically with ribs extending from marginal areolar pores through the frontal wall and ending at the top of the umbo. Marginal areolar pores of medium size; there are about 10-15 pores on the border of each autozooecium. Aperture large, oval with concave proximal margin. An adventitious avicularium, without pivotal bar, is situated in the middle of the frontal wall, proximally from the aperture, on the top of the umbo. It may be rarely developed as a giant avicularium with pivotal bar and an oval rostrum. No suboral avicularia. Ovicell partly immersed, globular with “U”-shaped pores arranged on its frontal wall.

R e m a r k s: As shown by Schmid (1989) and Pouyet (1997) Eschara macrocheila REUSS, 1847 and Cellepora endlicheri REUSS, 1847 represent the same species. The variability of avicularia and also the general morphology were discussed by Schmid (1989).

Umbonula cf. macrocheila ( REUSS, 1847) Pl. 93, Fig. 1-4

M a t e r i a l: Only one specimen with rather unusual features was found.

147 D i a g n o s i s: Colony encrusting. Autozooecia oval with convex, smooth frontal wall, characteristically with ribs extending from marginal areolar pores through the frontal wall and ending at the top of the umbo. Marginal areolar pores of medium size, there are about 10-15 pores on the border of each autozooecium. Aperture large, oval with concave proximal margin. An adventitious avicularium, without pivotal bar, is situated in the middle of the frontal wall, proximally from the aperture, on top of the umbo. No suboral avicularia. Ovicell partly immersed, globular, with three longitudinal ridges.

R e m a r k s: Very similar to Umbonula macrocheila ( REUSS, 1847) ; it differs only with respect to the structures of the ovicell. Umbonula macrocheila ( REUSS, 1847) has a “U”-shaped row of pores on its ovicell, while this specimen has three longitudinal ridges on the frontal wall of the ovicell (Pl. 92, Fig. 3 and 4). As only one specimen has been found, the establishment of a new species was not justified.

Umbonula spinosa ( PROCHÁZKA, 1893) Pl. 94, Fig. 1-8

v. * 1893 Eschara spinosa nov. spec. – Procházka p. 51 (67), Pl. 12, Fig. 5a-g

v. 1996 Umbonula spinosa (PROCHÁZKA) – Sváček p. 72, Fig. 1

v. 2009 Umbonula spinosa ( PROCHÁZKA, 1893) – Zágoršek et al., p. 480 11D-G

T y p e: Neotype established by Zágoršek et al (2009) deposited in NM Prague under the number NM PM2 -P 1354.

M a t e r i a l: Altogether 18 specimens were studied, all from the locality Kralice nad Oslavou .

D i a g n o s i s: Colony erect, massive with an oval cross section. Autozooecia with small marginal areolar pores (about 10-15 pores on the border of each autozooecium). Frontal wall with one “usual” large umbo with a small, adventitious avicularium without pivotal bar and additional small, umbo-like tubercles, resembling short spines, without any avicularia. Primary orifice with a wide lyrula. Ovicell globular, deeply immersed with a slightly perforate ectoecium (Pl. 94, Fig. 2). From the interior the umbonuloid frontal wall is clearly recognizable (Pl. 94, Fig. 7-8).

R e m a r k s: Detailed description and discussion is presented in Zágoršek et al. (2009)