Trypostega rugulosa ( REUSS , 1874)

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

Trypostega rugulosa ( REUSS, 1874)

Pl. 74, Fig. 1-5

v. * 1874 Lepralia rugulosa m. – Reuss p. 169, Pl. 3, Fig. 2

1977 Hippoporina rugulosa (REUSS) – Vávra p. 107

v. 2003 Arthropoma rugulosa (REUSS) – Zágoršek p. 175, pl. 28, fig. 3 (cum. syn)

2006 Trypostega rugulosa (REUSS) – Berning p. 56, Fig. 55, 56 (cum syn.)

T y p e: Lectotype deposited in the Natural History Museum Vienna under the number 1878.11.65. ( David and Pouyet, 1974).

M a t e r i a l: Altogether 7 specimens were studied in detail (2 specimens from Hlohovec, 3 specimens from Podbřežice, one from Přemyslovice, Rebešovice and Holubice).

D i a g n o s i s: Colony encrusting, autozooecia oval to elongate hexagonal, sometimes irregularly elongated. The frontal wall is smooth and shows a few regularly distributed large pores. Aperture keyhole-shaped (‘cleithridiate’) without oral spines. The distal part is large and semicircular, the proximal part (sinus) small and wide. The condyles are distinct. Kenozooecia often developed, irregular. Heterozooecia rare, irregularly developed, situated between the autozooecia, irregularly, of droplike shape, with a circular orifice. Ovicell large, globular; it has a porous frontal wall. Avicularia are unknown.

R e m a r k s: Specimens found at Hlohovec have fewer frontal pores than the syntypes deposited in the Museum of Natural History in Vienna. The preservation of pores could however be caused by the fossilization process. The large ovicell – characteristic for this genus ( Hayward and Ryland, 1999) – is identical with the syntypes, but Trypostega has to have heterozooecia with an orifice regularly interspersed among autozooecia ( Hayward and Ryland 1999). The heterozooecia have been described here for the first time, orifices of heterozooecia have not been observed in this species. Hippothoa as re-described by Tilbrook (2006) has no heterozooecia. Another similar genus is Arthropoma , which differs however in having an ovicell with a nonporous frontal wall and a narrower sinus. Overall, Trypostega seems to be the most suitable for the species.