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
Author
ZÁGORŠEK, KAMIL
National Museum, Prague, Václavské nám. 68,115 79 Praha 1, Czech Republic
kamil_zagorsek@nm.cz
text
Acta Musei Nationalis Pragae Series B
2010
66
3 - 4
139
255
journal article
10.5281/zenodo.13344847
2533-4069
13344847
Umbonula granulata
sp. n.
Pl. 95, Fig. 1-6
D i a g n o s i s: Colony encrusting. Autozooecia rhomboidal with granular frontal wall. Marginal areolar pores small, about 10-15 on the border of each autozooecium. Aperture with a large lyrula. Avicularia of
two types
, small suboral and giant spatulate. No ovicell observed.
H o l o t y p e: The specimen illustrated in Pl. 95, Fig. 1 and 4-6, from the section Podbřežice, is deposited in the National Museum
Prague
under number PM2 – P 01903.
P a r a t y p e s: Altogether
4 specimens
were studied from the locality
Podbřežice
, deposited in the
National Museum
Prague
under numbers
PM2
– P 01904-P 01907.
148
D e r i v a t i o n o m i n i s: Due to the granular frontal wall.
L o c u s t y p i c u s: section Podbřežice, sample Podbřežice village-1.
S t r a t u m t y p i c u m: Langhian – Lower Badenian.
M e a s u r e m e n t s: (in micro meters = µm; x = = average):
length of autozooecia: 499-654; x = 614
width of autozooecia: 333-492; x = 396
length of autozooecial aperture: 152-231; x = 180
width of autozooecial aperture: 157-193; x = 176
length of suboral avicularium: 65-112; x = 85
width of suboral avicularium: 57-85; x = 72
length of spatulate avicularium: 275-299; x = 287
width of spatulate avicularium: 164-197; x = 181
diameter of areolar pore: 20-68; x = 48
D e s c r i p t i o n: Colony encrusting. Autozooecia rhomboidal with flat, granular frontal walls. Granules small, regularly arranged in quincuncial pattern. Marginal areolar pores small, there are about 10-15 pores on the bor- der of each autozooecium. Aperture large, oval with a large lyrula. Adventitious avicularia suboral or spatulate. Suboral avicularia with a pivotal bar (Pl. 95, Fig. 6); they are situat- ed on the middle of the frontal wall, proximally from the aperture, at the top of the umbo. The spatulate avicularia are giant, with an oval rostrum and a pivotal bar (Pl. 95, Fig. 3). No ovicell observed.
C o m p a r i s o n: This new species is very similar to
Eschara chiragra
Manzoni,
1877
in having a granular frontal wall, but it differs in having giant avicularia and encrusting colonies (
Eschara chiragra
MANZONI
, 1877
forms bilaminar colonies).
Umbonula spinosa
(
PROCHÁZKA
, 1893
)
resembles this new species in having the “spines” similar to granules around the autozooecia. The granules are however much smaller than the tubercles on
Umbonula spinosa
(
PROCHÁZKA
, 1893
)
. There are no ridges on the frontal wall as in
Umbonula macrocheila
(
REUSS
, 1847
)
and the autozooecia in
Umbonula granulata
sp. n.
are of a more rhomboidal shape.