Reptadeonella BUSK, 1884

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

Genus Reptadeonella BUSK, 1884

Encrusting colony. Primary aperture semicircular. Frontal wall with marginal areolar pores and a central spiramen. Avicularia adventitious, placed centrally on the frontal wall. No ovicells, but brooding gonozooecia present.

Reptadeonella cf. violacea (JOHNSTON, 1847) Pl. 78, Fig. 1-6

v. 1977

?1999

? 2002

Reptadeonella violacea (JOHNSTON, 1847) – Vávra p. 149 (cum syn.)

Reptadeonella violacea (JOHNSTON, 1847) – Hayward and Ryland p. 186, Fig. 70A, B, 71 (cum syn.) Reptadeonella violacea (JOHNSTON, 1847) – Hayward and McKinney p. 44, Fig. 19D-G (cum syn.)

M a t e r i a l: Altogether 10 specimens were studied from the borehole Vranovice VK-1 only.

D i a g n o s i s: Colony encrusting, multilaminar. Autozooecia regularly hexagonal, rarely rather oval, with an umbonuloid frontal shield, marginal areolar pores are large. Primary orifice without a sinus, secondary aperture on a short peristome. Spiramen semilunar, with small condyles on the distal margin. Numerous, circular basal pore chambers are arranged in rows. Avicularia median, small, drop-like, tapering distally. Gonozooecia not observed.

R e m a r k: The fossil material is very similar to recent specimens as described by Hayward and Ryland (1999), but differs mainly in respect to the shape of the spiramen. The recent specimens have an almost circular shaped spiramen, but the fossil ones (studied specimens as well as specimens described by Vávra, 1977) often have a semilunar or even slightly curved spiramen, while some autozooecia in the same colony may also have circular spiramina. Without knowing more about the intraspecific variability of this species, an exact determination of the fossil material is impossible.