Upper Devonian (Frasnian) Bryozoa from the Shishtu 1 Formation of Niaz area (eastern Tabas, central Iran)
Author
Ernst, Andrej
Author
Tolokonnikova, Zoya
Author
Yarahmadzahi, Hamed
text
Revue de Paléobiologie
2012
2012-07-31
31
1
1
14
journal article
0253-6730
[=
Reteporidra
NICKLES & BASSLER, 1900
]
Type
species:
Fenestella cinctuta
HALL, 1884
. Middle Devonian (Erian);
Canada
and USA.
Diagnosis:
Fan-shaped colonies, some with heavy extrazooidal calcification covering proximal portion of colony; branches broad, strongly sinuous, bifurcating, branch spacing and anastomoses at intermediate distance; keels and superstructure absent; autozooecia arranged in 2-8 rows on branches, large-end intermediate-sized, elongate perpendicular to curved obverse surface, chambers nearly circular oval in tangential section deep in endozone, elongate oval in shallower endozone; transverse wall at high angle to reverse wall; hemisepta and diaphragms absent; elevated peristome present in well preserved specimens. Tubes connecting the endozonal zooecial chambers with the obverse surface present, few or abundant, varying in size. Autozooecial walls of thick granular material may be lined by laminar skeleton in both the distal tube and the inflated chamber; reverse wall flat or minimally curved transversely, longitudinal ridges on reverse side minimally developed; extrazooidal skeleton finely laminated, traversed by closely spaced small microstyles, a gently sloped median keel commonly present on reverse surface, locally forming cystose structures bridging fenestrules where broad expanse of extrazooidal skeleton is deposited as continuous sheet over multiple branches.
Remarks:
Anastomopora
SIMPSON, 1897
differs from the similar genus
Reteporina
D’ ORBIGNY,
1849
in having more than 2 rows of autozooecia on branches. Both genera possess exozonal tubes, which number and size are variable in different species.
Stratigraphic and geographic range:
Lower-Late Devonian; North America, Europe, Asia (Carboniferous and Permian species referred to the genus
Reteporidra
, do not belong to the
Anastomopora
).