Schizoporella dunkeri ( REUSS , 1847)

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

Schizoporella dunkeri ( REUSS, 1847)

Pl. 104, Fig. 1-5

v. * 1847 Cellepora dunkeri m. – Reuss p. 90, Pl. 10, Fig. 27

1989 Schizoporella dunkeri ( REUSS, 1847) – Vávra p. 116 (cum syn.)

2006 Schizoporella dunkeri ( REUSS, 1847) – Berning p. 84, Fig. 94, 96, 99, 100, 104 (cum syn.)

T y p e: Lectotype was selected by David and Pouyet (1974); it is deposited in the Natural History Museum Vienna under the number 1846.37.996.

M a t e r i a l: Only 11 specimens were found in the studied sections.

D i a g n o s i s: Colony encrusting. Autozooecia oval with oval pores on its frontal wall. Frontal wall convex, a small umbo formed close to the proximal edge of the aperture. Aperture on a short peristome usually situated symmetrically in the middle of the distal margin of the frontal wall with a long but very narrow sinus. Avicularia suboral, large, situated in an additional chamber, with pivotal bar. Sometimes two avicularia, situated on both sides of the aperture. Ovicell unknown.

R e m a r k s: The characteristic features are the aperture with its narrow sinus, the presence of an umbo and the large suboral avicularium.

151

Schizoporella? geminipora ( REUSS, 1847) Pl. 105, Fig. 1-7 v.* 1847 Vaginopora geminipora m. – Reuss p. 74, Pl. 9, Fig. 3-4

v. * 1974 Schizoporella geminipora (REUSS) – David and Pouyet p. 158, Pl. 8, Fig. 4(cum syn.)

1977 Schizoporella geminipora (REUSS) – Vávra p. 117 (cum syn.)

v. 1989 Schizoporella geminipora (REUSS) – Schmid p. 38, Pl. 11, Fig. 2-4

1997 Schizoporella geminipora (REUSS) – Pouyet p. 53 (cum syn.)

T y p e: Lectotype (defined by David and Pouyet, 1974) is deposited in the Natural History Museum Vienna under the number 1846.37.992.

M a t e r i a l: Common species; more than 40 specimens from different sections were studied in detail. An additional 3 specimens from the Reuss collection stored in the Natural History Museum Vienna under the numbers 1878.11.112, 1878.11.143 and 1878.11.86 (which is the type of Lepralia crassa – see David and Pouyet, 1974) from the sections Podivín (listed under the old name Kostel) and Sedlec (listed under the old name Porzteich) were included in our studies .

D i a g n o s i s: Colony unilaminar, probably encrusting a soft surface. Dorsal side of the colony is formed by dorsal walls of autozooecia with a central un-calcified area. Autozooecia oval to rectangular, indistinct, with a strongly porous frontal wall. Aperture circular with a sinus. Avicularium on the frontal wall, usually arranged laterally to the aperture, with a pivotal bar. Brooding autozooecia (intrazooecial ovicells) are much larger than autozooecia, usually with two avicularia.

R e m a r k s: The species was traditionally listed as Schizoporella , a genus with avicularia adjacent to the aperture and a recumbent, prominent, globular or spherical ovicell with a porous frontal wall (as defined by Hayward and Ryland, 1999). In Schizoporella? geminipora ( REUSS, 1847) the avicularia are situated more on the frontal wall (even close to the aperture); the zooarium always develops only a unilaminar colony with characteristic smooth dorsal walls with large oval openings. This development of the dorsal side of the colony lead Vávra (1984) to suggest that this species was growing on algal stems and it may therefore be an indicator of posidonia-like meadows. Moreover, the presence of intrazooecial ovicells clearly separates these two genera.

The ovicells were not described in the lectotype ( David and Pouyet, 1974) or in other specimens. It was believed, that no ovicells were developed. The large brooding zooecium (Pl. 105, Fig. 1 and 3) suggests internal brooding or an intrazooecial ovicell; this can be regarded as an important reason for establishment of a new genus, separating this taxon from the traditional assignment to Schizoporella . Moreover, no other species of Schizoporella shows such a characteristic development of the dorsal walls and position of the avicularia more on the frontal wall than near the aperture. However, more brooding specimens should be studied to decide for the new genus.