Synonymy and circum-tropical biogeography of the Devonian calcareous alga Zeapora Penecke, 1894 (Chlorophyta, Bryopsidales)

Island Arc ◽  
2017 ◽  
Vol 26 (3) ◽  
pp. e12187 ◽  
Author(s):  
Bernhard Hubmann ◽  
Markus Reuter
Keyword(s):  
Calcareous Alga

Calcareous meiofauna associated with the calcareous alga Corallina officinalis on bedrock and boulder-field shores of Ceredigion, Wales, UK

2020 ◽  
pp. 1-13
Author(s):  
Brent Wilson ◽  
Lee-Ann C. Hayek
Keyword(s):  
Breaking Waves ◽  
Red Alga ◽  
Low Energy ◽  
Rock Pools ◽  
Lower Shore ◽  
Calcareous Alga ◽  
Corallina Officinalis ◽  
Modes Of Life ◽  
Sessile Organisms

Abstract The intertidal coastline of Ceredigion, Wales, comprises a patchwork of unstable sand and cobble beaches, and stable bedrock areas and boulder-fields. The last two shoreline types support rock-pools with growths of the red alga Corallina officinalis, the thalli of which are a popular substrate for calcareous epiphytes. Replicate samples of C. officinalis (four per site) were taken from (a) three bedrock sites (Ceinewydd, Aberystwyth Victoria Rocks and Castle Rocks) and (b) three boulder-fields (Llanon, Aberaeron lower shore (Aberaeron LS), Llanina) on the lower shore. The middle shore boulder field at Aberaeron (Aberaeron MS) was also sampled. These replicates were examined for calcareous meiofauna (63–2000 μm) not previously examined as a community: spirorbids, foraminifera, gastropods, bryozoans, ostracods and ophiuroids. These were assigned to sessile and vagile modes of life. The sessile association overwhelmingly dominated bedrock coastlines and the Aberaeron MS, while the vagile association was at its most abundant on the Corallina from lower shore, stable boulder-fields. Gastropods were almost entirely limited to Corallina on boulder-fields. We hypothesize that the boulders induce low-energy turbulence among breaking waves, allowing the less firmly attached vagile meiofauna to dominate on C. officinalis in rock-pools in lower shore boulder-fields. The small attachment area of sessile organisms allows them to settle bedrock sites in greater densities than do vagile organisms at boulder-field sites, which are presumed to require larger foraging areas.

Amsassia (calcareous alga) from the Lower Ordovician (Tremadocian) of western Newfoundland, and the biologic affinity and geologic history of the genus

2021 ◽  
pp. 1-18
Author(s):  
Dong-Jin Lee ◽  
Robert J. Elias ◽  
Brian R. Pratt
Keyword(s):  
South China ◽  
Geologic History ◽  
Shallow Marine ◽  
Middle Ordovician ◽  
Calcareous Alga ◽  
Tarim Block ◽  
Lower Ordovician ◽  
History Of ◽  
Argentine Precordillera ◽  
Extinct Group

Abstract Modular coral-like fossils from Lower Ordovician (Tremadocian) thrombolitic mounds in the St. George Group of western Newfoundland were initially identified as Lichenaria and thought to include the earliest tabulate corals. They are here assigned to Amsassia terranovensis n. sp. and Amsassia? sp. A from the Watts Bight Formation, and A. diversa n. sp. and Amsassia? sp. B from the overlying Boat Harbour Formation. Amsassia terranovensis n. sp. and A. argentina from the Argentine Precordillera are the earliest representatives of the genus. Amsassia is considered to be a calcareous alga, possibly representing an extinct group of green algae. The genus originated and began to disperse in the Tremadocian, during the onset of the Great Ordovician Biodiversification Event, on the southern margin of Laurentia and the Cuyania Terrane. It inhabited small, shallow-marine reefal mounds constructed in association with microbes. The paleogeographic range of Amsassia expanded in the Middle Ordovician (Darriwilian) to include the Sino-Korean Block, as well as Laurentia, and its environmental range expanded to include non-reefal, open- and restricted-marine settings. Amsassia attained its greatest diversity and paleogeographic extent in the Late Ordovician (Sandbian–Katian), during the culmination of the Great Ordovician Biodiversification Event. Its range included the South China Block, Tarim Block, Kazakhstan, and Siberia, as well as the Sino-Korean Block and Laurentia, and its affinity for small microbial mounds continued during that time. In the latest Ordovician (Hirnantian), the diversity of Amsassia was reduced, its distribution was restricted to non-reefal environments in South China, and it finally disappeared during the end-Ordovician mass extinction. UUID: http://zoobank.org/ef0abb69-10a6-46de-8c78-d6ec7de185fe

The Permian Calcareous Alga Gymnocodium

1955 ◽  
Vol 1 (1) ◽  
pp. 83 ◽  
Author(s):  
Graham F. Elliott
Keyword(s):  
Calcareous Alga

Calcipatera cottonwoodensis, a new membranous late Paleozoic calcareous alga

1992 ◽  
Vol 66 (4) ◽  
pp. 678-681 ◽  
Author(s):  
A. M. Torres ◽  
R. R. West ◽  
R. S. Sawin
Keyword(s):  
New Species ◽  
Internal Structure ◽  
Cross Section ◽  
Morphological Type ◽  
Late Paleozoic ◽  
Lower Permian ◽  
Serial Sections ◽  
Calcareous Alga

A new morphological type of Paleozoic calcareous alga is represented by Calcipatera cottonwoodensis n. gen. and sp., a codiacean species found in the Cottonwood Limestone Member, Lower Permian, of eastern Kansas. The new species, as reconstructed from serial sections of weathered out, in situ, intact specimens, had a broadly obconical, cup-like membranous thallus. The internal structure of the membrane as seen in cross section consisted of a medulla with mosaic sparry calcite and bilateral cortices with calcite packets forming utricular molds similar to those of other known membranous algae. The sparry calcite apparently replaced the lightly calcified or uncalcified intercoenocytic spaces in the medulla and the calcite crystals replaced the interutricular aragonite. The organism had previously been identified as Anchicodium Johnson.

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