Smittina cervicornis ( PALLAS , 1766)

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

Smittina cervicornis ( PALLAS, 1766)

Pl. 99, Fig. 1-6

1974

v. 1977 1989

v. 2001

2002

v. 2003

Porella cervicornis (PALLAS) – David and Pouyet p. 194 (cum syn)

Porella cervicornis (PALLAS) – Vávra p. 139 (cum. syn.) Porella cervicornis (PALLAS) – Schmid p. 35, Pl. 10, Fig. 1 – 3 (cum syn.)

Smittina cervicornis (PALLAS) – Zágoršek p. 55, Pl. 18, Fig. 7, 9, 10

Smittina cervicornis (PALLAS) – Hayward and McKinney p. 49, Fig. 22A-C (cum syn.)

Smittina cervicornis (PALLAS) – Zágoršek p. 163 (cum syn.)

M a t e r i a l: A very abundant species, it occurs in all studied sections. More than 60 specimens were examined in detail.

D i a g n o s i s: Colony erect, bilaminar with 6 to 7 autozooecial rows and an oval to circular cross section. Autozooecia elongate to oval with thin lateral walls. If secondary calcification is well developed, the shape of the autozooecia is irregular (Pl. 99, Fig. 1). Frontal wall strongly porous with large circular to polygonal pores. Aperture is large, oval to circular with large condyles and a wide lyrula, visible only from the interior of the autozooecia. Peristome wide and smooth, usually only slightly prominent, sometimes even immersed. Avicularium small, situated on the middle of the proximal margin of the aperture, sometimes inside the aperture. Ovicell is deeply immersed, it has a strongly perforated frontal wall.

R e m a r k s: Recent specimens (for example Hayward and McKinney, 2002) show the same development of their frontal wall with exactly the same position of the avicularia. The similarity with fossil material is really striking, no differences can be recognized. Therefore the fossils specimens are listed under this name.

Miocene specimens differ from Eocene ones in having large, usually polygonal (instead of oval), frontal pores. The ovicell of this species has not been illustrated in fossil material up to now.