Geology Reference
In-Depth Information
and as inorganic structures (Mazzullo and Cys 1977;
Wang et al. 1994; Grotzinger and Knoll 1995; Kendall
and Iannace 2001). A microbial origin is reliable.
Box 10.8.
Generic list of thin-section microproblem-
atica.
Many taxa may be cyanobacteria or algae but their
systematic position is not yet fully acknowledged. More
than 90% of thin-section fossils designated as micro-
problematica have been described from shallow-marine
reef or platform carbonates. Taxa found predominantly
or exclusively in open-marine pelagic 'deep-water' lime-
stones are marked by an asterisk.
Tertiary
:
Codiomorpha
Andrusov and Schalekova
1972,
Microcodium
Glück 1912,
*Pieninia
Borza and
Misik 1976,
Thaumatoporella
Raineri 1922
Baccanella
Pantic 1971 (Pl. 99/8)
Morphology:
The genus is characterized by small
regularly or irregularly developed spheres consisting
of radially arranged aggregates of calcite crystals start-
ing from a central point. The spheres are commonly
densely packed side by side. The calcite crystal aggre-
gates exhibit shapes resembling leaves of flowers. They
have been interpreted as branches that divide into
smaller ones near the periphery. The diameter of the
individual spheres varies between about 50 and 500
m.
Distribution:
The genus is a common constituent of
cryptic cavities in the central parts of Middle and Late
Triassic reefs.
Interpretation: Baccanella
has been regarded as al-
gae, bacteria, bacterially induced carbonate precipitate
or diagenetic product caused by recrystallization of mi-
critic High-Mg calcite and aragonite on the sea floor
(Pratt 1997). The last two explanations are reliable.
Cretaceous
:
Aeolisaccus
Elliott 1958,
Bacinella
Radoi-
cic 1959,
Carpathoporella
Dragastan 1967,
Cipro-
campylodon
Elliott 1963,
Cretacicrusta
Elliott 1972,
*Diademnoides
Bonet and Benviniste-Velasquez 1971,
*Didemnum
Savigny 1816,
*Gemeridella
Borza and
Misik 1975,
Getaia
Dragastan 1972,
*Globochaete
Lombard 1945,
Koskinobullina
Cherchi and Schröder
1979,
Lacrymorphus
Elliott 1958,
Lithocodium
Elliott
1956,
Microcodium
Glück 1912,
*Microlaminoides
Bonet 1956,
Palaeosiphonium
Elliott 1985,
*Pieninia
Borza and Misik 1976,
Thaumatoporella
Raineri 1922,
Tubiphytes
Maslov 1956
Jurassic
:
Aeolisaccus
Elliott 1958,
Axothrix
Nagy 1971,
Bacinella
Radoicic 1959,
*Diademnoides
Bonet and
Benviniste-Velasquez 1971,
*Didemnum
Savigny 1816,
Enigma
Eliasova 1981,
Fusanella
Eliosova 1981,
*Gemeridella
Borza and Misik 1975,
*Globochaete
Lombard 1945,
Koskinobullina
Cherchi and Schröder
1979,
Lithocodium
Elliott 1956,
Microcodium
Glück
1912,
Muranella
Borza 1975,
Palaeosiphonium
Elliott
1985,
*Palaeothrix
Ferasin 1956,
Polygonella
Elliott
1957,
Thaumatoporella
Raineri 1922,
Tubiphytes
Mas-
lov 1956,
*Verticillodesmis
Dragastan and Borza 1975
Bacinella
Radoicic 1959 (Pl. 99/4)
Morphology:
Epibenthic cell assemblages forming
crusts or nodules consisting of relatively regular, some-
times parallel irregularly shaped cells. The assemblage
is surrounded by an exterior wall. The cells may be
circular, rectangular or triangular in cross section. They
are filled with sparry calcite. Cell walls are thin. Cell
diameter between 100 and 500
m
.
Distribution:
The genus is known from Middle Tri-
assic to Late Cretaceous deposits. It was originally de-
scribed from the Cretaceous.
Bacinella
is a common
fossil in Ladinian reef limestones, but occurs also in
Late Triassic reef carbonates and is abundant in Juras-
sic and Early Cretaceous platform carbonates.
Bacinella
is often intimately associated with
Lithocodium.
Interpretation:
The genus is still enigmatic. It was
interpreted as codiacean alga, compared with hydrozo-
ans, and explained as ecotypes of bacterial associations
(Neuweiler and Reitner 1992) or as cyanobacteria.
Triassic
:
Actinotubella
Senowbari-Daryan 1984,
Aeolisaccus
Elliott 1958,
Baccanella
Pantic 1971,
Bacinella
Radoicic 1959,
Barbafera
Senowbari-Daryan
1984,
*Diademnoides
Bonet and Benviniste-Velasquez
1971,
*Didemnum
Savigny 1816,
*Gemeridella
Borza
and Misik 1975,
*Globochaete
Lombard 1945,
Lad-
inella
Ott 1968,
Ladinosphaera
Oberhauser 1960,
Lamellitubus
Ott 1968,
Lithocodium
Elliott 1956,
Macrotubus
Fois and Gaetani 1981,
Messopotamella
Dragastan et al. 1985,
Microcodium
Glück 1912,
Microtubus
Flügel 1964,
Muranella
Borza 1975,
Panormidella
Senowbari-Daryan 1984,
Paraeolisaccus
Senowbari-Daryan and Schäfer 1980,
Plexoramea
Mello 1977,
Porferitubus
Senowbari-Daryan 1984,
Radiomura
Senowbari-Daryan and Schäfer 1978,
Thaumatoporella
Raineri 1922,
Tubiphytes
Maslov 1956
Globochaete
Lombard 1945 (Pl. 99/1)
Morphology:
The genus is characterized by spheri-
cal and kidney-shaped calcitic bodies with a micritic
nucleus, about 30 to 100
m in size, occurring in clus-
ters, isolated or serially arranged, sometimes attached
to thin calcitic plates corresponding to 'filaments'. An
axial cross between crossed nicols indicates a construc-
tion of radially arranged calcite fibers. The bodies ex-
hibit a sparry wall, appearing yellowish in transmitted
light, and sometimes showing a micritic boundary.
Permian
:
Aeolisaccus
Elliott 1958.
Archaeolithoporella
Endo 1959,
Koivaella
Chuvashov 1974,
*Globochaete
Lombard 1945,
Palaeoaplysina
Krotow 1888,
Pseudo-
vermiporella
Elliott 1958,
Tubiphytes
Maslov 1956
Carboniferous
:
Archaeolithoporella
Endo 1959,
*Globochaete
Lombard 1945,
Koivaella
Chuvashov
1974,
Palaeoaplysina
Krotow 1888,
Tubiphytes
Maslov
1956
