Topic
Cymopolia
About: Cymopolia is a research topic. Over the lifetime, 28 publications have been published within this topic receiving 403 citations.
Papers
TL;DR: Calcareous green algae (CGA) are an artificially united but highly heterogeneous group of large unicellular benthic algae with one character in common: all have the capability of secreting a calcareous coating on the outer side of the cytoplasmic envelope as discussed by the authors.
Abstract: Calcareous green algae (CGA) are an artificially united but highly heterogeneous group of large unicellular benthic algae with one character in common: all have the capability of secreting a calcareous coating on the outer side of the cytoplasmic envelope. Today, they are a major contributor to carbonate sedimentation at all scales from clay-sized particles (aragonitic needles) to coarser grains (sand and gravel) and even to plurimetric sedimentary structures. There are fossil analogues to the features listed above. Phycologists know best Halimeda, Penicillus, Acetabularia and Cymopolia; micropaleontologists and carbonate sedimentologists are most knowledgeable about Acicularia, Clypeina, Neoteutloporella, Salpingoporella, Anthracoporella, Boueina, and Eugonophyllum. The CaCO3 precipitated to form the coating is generally aragonite (the orthorhombic form) but there are short periods in the geologic record during which its calcite variant (the rhombohedric form) existed contemporaneously in discrete species. Recent studies on Halimeda have shown that some of the Bryopsidales have the capability to calcify strongly in the lower portion of the euphotic zone (where respiration becomes more important than photosynthesis in the process of mineralization) and to produce positive sedimentary reliefs (bioherms) in situ below the fair-weather wave base. Previous models of paleoenvironments considered the presence of Dasycladales or Bryopsidales to indicate shallow-water, that is the upper euphotic zone (from the sea surface down to -25 m), and predominantly low-energy, protected, lagoonal environments. When the algal remains were found in grain-supported facies, they were taken to have been subjected to dynamic transport and therefore indicative of high-energy environments of deposition. The new deeper-water finds have changed interpretations of the environments ascribed fossil algae. A current conception is that ancestral inarticulated Bryopsidales could have grown at depths as great as -120 m (near the base of the lower euphotic zone). This preliminary review concludes with suggestions about fields for continuing investigations.
97 citations
TL;DR: Relationships among the Acetabulariaceae show that AcetABularia and Polyphysa do not form monophyletic groups as presently circumscribed, and no evidence indicates that Acicularia is the oldest genus.
Abstract: Phylogenetic relationships were inferred from parsimony and distance analyses of nuclear small-subunit ribosomal DNA sequences taken from 14 species representing 8 Of the 11 extant genera in the Dasycladales. Of 1733 aligned positions, 412 (23.8%) were variable and 251 (61%) of those were phylogenetically informative within the Dasycladales. Secondary structure was analyzed and taken into account during all phases of data analysis. Robustness of the trees was assessed using bootstrap analysis and g, statistics of tree-length decay. Strongly supported branches were robust to all methods of analysis regardless of weighting schemes used. The secondary structure of the 18S within the Dasycladales agrees with that of other green algae with the exception of a shared deletion in stemloop E10-1 (ca. 13 nucleotides long), which provides additional support for the uniqueness of this monophyletic group. A molecular clock was calibrated from the dasyclad fossil record and suggests a radiation of the Acetabulariaceae at 120 +/- 3O million years (Ma) ago and the Dasycladaceae 215 +/- 40 Ma ago. The split of the two lineages from a shared ancestor is estimated at 265 +/- 50 Ma ago. Within the Dasycladaceae, Neomeris and Cymopolia are sister taxa, as are Batophora and Chlorocladus. Bornetella groups with the Neomeris and Cymopolia clade in 78% of the bootstrap replicates. Re Relationships among the Acetabulariaceae show that Acetabularia and Polyphysa do not form monophyletic groups as presently circumscribed. No evidence indicates that Acicularia is the oldest genus. Halicoryne, Chalmasia, and Dasycladus were not included in the analysis. Molecular data provide afresh background perspective from which to discuss the evolution of one of the most ancient lineages of green plants.
59 citations
[...]
1 Jan 1901
TL;DR: The earliest reference to the algae of Jamaica, and very nearly the earliest reference for America, appears to be by Sloane ; in the chapter on submarine plants 43 species are named and described, among which, however, are a few aquatic phanerogams, and a considerable number of corals.
Abstract: The earliest reference to the algae of Jamaica, and very nearly the earliest reference to the algae of America, appears to be by Sloane ; * in the chapter on submarine plants 43 species are named and described, among which, however, are a few aquatic phanerogams, and a considerable number of corals ; of the remainder most are too vaguely described to be now identified, but by the help of the plates, we can give with fair cer tainty the modern names for four. Vol. I. p. 57, PL XX. Fig. 2, Corallina opuntioides, ramulis den sioribus, et filis magis sinuatis atque corrugatis, is Halimeda Opuntia. P. 58, PL XX. Fig. 3, Corallina major, nervo crassiore fuciformi, inter nodia breviora nectente, White Bead Bandstring dicta, is Cymopolia bar bata. P. 61, PL XX. Fig. 9, Fucus minimus denticulatus triangularis, is Bryothamnion triangulare. P. 58, PL XX. Fig. 6, Fucus marinus vesi culas habens membranis extantibus alatas, is Turbinaria trialata. P. 58, PL XX., Corallina minima capillacea, is probably our present Corallina capillacea, but neither plate nor description is characteristic enough to make this certain. P. 51, PL XVIIL, Corallium album pumi lum nostras, seems to be some species of Lithothamnion. The other de scriptions are too uncertain to hazard any identifications. A few algae are mentioned by Browne,f apparently mostly copied from Sloane ; some plants undoubtedly belonging to the genus Sargassum are mentioned, and from the description of the great floating masses, S. bacciferum is undoubtedly meant, but it is probable that other species are included under this name.
39 citations
TL;DR: The phylogeny of the green algal Order Dasycladales was inferred by maximum parsimony and Bayesian analyses of chloroplast‐encoded rbcL sequence data and suggested that the tribe Acetabularieae is monophyletic but that some genera within the tribe are not, casting doubt on the current family‐level classification.
Abstract: The phylogeny of the green algal Order Dasycladales was inferred by maximum parsimony and Bayesian analyses of chloroplast-encoded rbcL sequence data. Bayesian analysis suggested that the tribe Acetabularieae is monophyletic but that some genera within the tribe, such as Acetabularia Lamouroux and Polyphysa Lamouroux, are not. Bayesian analysis placed Halicoyne Harvey as the sister group of the Acetabularieae, a result consistent with limited fossil evidence and monophyly of the family Acetabulariaceae but was not supported by significant posterior probability. Bayesian analysis further suggested that the family Dasycladaceae is a paraphyletic assemblage at the base of the Dasycladales radiation, casting doubt on the current family-level classification. The genus Cymopolia Lamouroux was inferred to be the basal-most dasycladalean genus, which is also consistent with limited fossil evidence. Unweighted parsimony analyses provided similar results but primarily differed by the sister relationship between Halicoryne Lamouroux and Bornetella Munier-Chalmas, thus supporting the monophyly of neither the families Acetabulariaceae nor Dasycladaceae. This result, however, was supported by low bootstrap values. Low transition-to-transversion ratios, potential loss of phylogenetic signal in third codon positions, and the 550 million year old Dasycladalean lineage suggest that dasyclad rbcL sequences may be saturated due to deep time divergences. Such factors may have contributed to inaccurate reconstruction of phylogeny, particularly with respect to potential inconsistency of parsimony analyses. Regardless, strongly negative g 1 values were obtained in analyses including all codon positions, indicating the presence of considerable phylogenetic signal in dasyclad rbcL sequence data. Morphological features relevant to the separation of taxa within the Dasycladales and the possible effects of extinction on phylogeny reconstruction are discussed relative to the inferred phylogenies.
38 citations
TL;DR: In this article, the geographical distribution of some fossil algal records (Chlorophyta: Dasycladales and Caulerpales) from the Upper Triassic onwards, in the light of post-Pangaean continental block separation, shows an essentially Tethyan dispersal pattern in the Mesozoic and Early Caenozoic.
34 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 2 |
| 2019 | 1 |
| 2018 | 2 |
| 2014 | 1 |
| 2013 | 1 |
| 2012 | 1 |