1,721,015 research outputs found
Re-description of Ishijima?s types of coralline algal species (Corallinales, Rhodophyta)
No full textRe-description of some Ishijima's type collections regading fossil coralline red algal species (Corallinales, Rhodophyta)
Re-assessment of the type collections of corallinalean species (Corallinales, Rhodophyta) described by W. Ishijima (1942–1978).
No full textMany species of fossil coralline algae have been separated on the basis of only a few characters with slight or doubtful taxonomic significance. The analysis of the type material of the fossil coralline algal species is, therefore, needed in order to assess the taxonomic status and circumscription of these taxa. Wataru Ishijima has been one of the most prolific Japanese palaeontologists who worked on fossil calcareous algae from the western Pacific region. Ishijima described a large number of new taxa of fossil calcareous algae mostly belonging to the Corallinales from Eocene to Pleistocene sedimentary successions. An analysis of some Ishijima's types of Corallinales (Rhodophyta) described from 1942 to 1960, currently housed in the Institute of Geology and Paleontology, Graduate School of Science, Tohoku University, Sendai (Japan), is presented. For fourteen taxa changes were made to previously published statements of typification. Re-examination of the types from a modern perspective of coralline algal taxonomy shows that Hydrolithon taishakuensis (Ishijima) comb. nov (= Lithothamnium taishakuensis), Sporolithon kobamazimensis (Ishijima) comb. nov. (= Archaeolithothamnium kobamazimensis), Sporolithon kuboiensis (Ishijima) comb. nov. (= Archaeolithothamnium kuboiensis) and Sporolithon taiwanensis (Ishijima) comb. nov. (= Archaeolithothamnium taiwanensis) showed significant features justifying their use as species names in coralline algal taxonomy. No diagnostic characters occur in two types (L. nishiwadai, L. otsukiensis) and therefore the taxonomic disposition of these taxa remains unknown. Lithophyllum quadratum Ishijima is a heterotypic synonym of Lithophyllum incrustans Philippi. Lithoporella crassa Ishijima and Lithoporella hayasakai Ishijima are considered heterotypic synonyms of Lithophyllum prototypum (Foslie) Foslie, while Porolithon hanzawai Ishijima is a heterotypic synonym of Hydrolithon onkodes (Heydrich) Penrose and Woelkerling. Mesophyllum arakuraensis Ishijima is co-specific and has nomenclatural priority over M. contii Ishijima. However M. arakuraensis and M. contii do not show available evidence whether either might belong to Synarthrophyton instead of Mesophyllum. Lithothamnium ishizuchiensis Ishijima and L. kasedaensis Ishijima have no diagnostic features that can be used to ally them to any particular genus or species of Melobesioideae
Hydrolithon braganum sp. nov. (Corallinaceae, Rhodophyta), the first known exclusively fossil semi-endophytic coralline red alga
No full textHydrolithon braganum sp. nov., the first known exclusively fossil semi-endophytic species of Corallinaceae (Corallinales, Corallinophycidae, Rhodophyta), is based on material from IODP Expedition 310 cores of Last deglacial age (c. 20,000 – 10,000 years BP) from reef terraces around Tahiti, French Polynesia. A detailed morphological-anatomical account is provided, and the taxonomic position of the new species at generic and subfamily levels is considered in relation to recent molecular studies and consequent proposals for changes to the concepts of the subfamily Mastophoroideae and the genus Hydrolithon. Evidence is presented to show that the morphological-anatomical criteria proposed in recent molecular-based studies are untenable for circumscribing the subfamily Mastophoroideae and for separating genera called Hydrolithon and Porolithon. Both the Mastophoroideae and Hydrolithon are best recognized as polyphyletic at present. It is not essential to superimpose a morphological-anatomical based classification system on a set of lineages inferred from analyses of molecular sequence data sets that are based only on genes not known to control any of the morphological-anatomical characters currently used to delimit subfamilies or genera, especially when this results in proposals that do not account for all included taxa and are, to varying extents, not in accord with the International Code of Botanical Nomenclature. An alternative strategy is to direct molecular systematic research more towards discovering which genes are responsible for morphological-anatomical characters used to delimit taxa of coralline red algae and then to use data from those genes along with SSU, LSU, psbA, and COI data in analyses aimed at elucidating monophyletic lineages and producing classification systems in which all included taxa are accounted for, and given valid taxonomic names, and assigned to valid taxonomic ranks that are in accord with the ICBN
Recent progress in study on calcareous algae and algal sediments
No full textThe International Fossil Algae Association (IFAA), an international group of scientists who are interested in any aspect of fossil and living algae, organizes an international symposium every 4 years. Okinawa was selected to host the 11th International Symposium on Fossil Algae (Figure 1) because of great contributions to the study of calcareous algae by Japanese scientists such as Ryuji Endo, Wataru Ishijima, and Kenji Konishi (Iryu, 2004) and easy accessibility to modern and Pleistocene coral reefs for which many sedimentological and paleontological studies have been performed for more than 100 years (e.g. Iryu et al., 2006). The Symposium was held on September 14–18, 2015 with the support of the Geological Society of Japan and the Palaeontological Society of Japan. A total of 13 scientists from five countries attended the symposium. Pre-symposium field excursions (September 14–15) visited modern dasycladacean meadows (Figure 2) and Pleistocene carbonate deposits on Okinawa-jima, Central Ryukyus and coral reefs off Kerama Islands. The next 2 days (September 16–17) were devoted for the scientific sessions at the University of the Ryukyus. A special session was organized to discuss “Morphology versus molecular evidence in determining algal taxonomy and phylogeny.” A post-symposium excursion was conducted on September 18. We visited the Shuri Castle and then observed Pleistocene carbonate successions on southern Okinawa-jima. Although the number of participants was limited, there were prolonged discussions for every presentation. This thematic section collects recent studies on calcareous algae and algal sediments by IFAA members. Five papers are assembled here, covering Devonian to modern materials from Europe, Africa, and Japan
Quando e dove comparsero le specie di alghe calcaree che oggi popolano gli oceani? Una storia di una lunga migrazione durata 27 milioni di anni.
No full textPaleobiogeografia delle specie del gruppo di Lithophyllum pustulatum
LE PRIME ALGHE ROSSE CORALLINACEE SEMI-ENDOFITE FOSSILI: RICERCHE DELL’IODP A TAHITI, POLINESIA FRANCESE
No full textBiogeographical patterns of the porcelaneous larger foraminifer Alveolinella quoyi through the integration of fossil data
Full text linkIn the present-day Indo-Pacific coral-reef settings two genera of alveolinoidean porcelaneous larger benthic foraminifera (LBF) occur, namely Alveolinella and Borelis. Alveolinella is represented by a single species, A. quoyi, whose northernmost record is in Okinawa-jima (central Ryukyu Islands, Japan). Although the Indo-Pacific area, and especially the Coral Triangle, is a biodiversity hotspot since the Early Miocene, in-depth investigation on fossil representatives of present-day LBF is limited to a few taxa. To help bridge this knowledge gap, the palaeobiogeographical dynamics of A. quoyi is assessed. Analysis of data from the palaeontological literature shows that its first appearance datum is from the Tortonian (Late Miocene) of East Kalimantan and Papua New Guinea. In the Pliocene–Pleistocene the Indonesian Throughflow constrained the species within the Central Indo-Pacific. Finally, during the Late Pliocene the northward migrants arrived in the shallow-water carbonate settings of Okinawa-jima where the species is still thriving
A new species of the larger porcelaneous foraminifer Borelis provides novel insights into Neogene to Recent western Pacific palaeobiogeographical dispersal patterns
No full textOnly three species of alveolinoidean larger foraminifera occur in present-day tropical shallow-water marine settings. Alveolinella quoyi thrives in the Central Indo-Pacific and Eastern Indo-Pacific, Borelis pulchra in the Central and Eastern Indo-Pacific and in the central Atlantic, whereas Borelis schlumbergeri inhabits the Indo-Pacific Ocean. The northernmost record is that of Alveolinella quoyi from the shallow-water settings in Okinawa (central Ryukyu Islands, Japan). A new porcelaneous larger foraminiferal species, Borelis matsudai sp. nov. (Alveolinoidea, Borelinae), is established herein, based on specimens discovered in present-day shallow-water sediments from Sekisei Lagoon, southern Ryukyu Islands (Japan). This is the northernmost record of the genus in the western Indo-Pacific Warm Pool. The architectural characters of this species suggest its phylogenetic relationship with the Borelis pulchra group. A comprehensive literature survey of fossil and modern records of Borelis pulchra over the past 30 million years shows that the Middle Miocene constriction of the Indonesian Seaway and the Late Miocene–Early Pliocene restriction of the Indonesian Throughflow impacted the species-level dispersal of this species in the Indo-Australian Archipelago. Driven by the Kuroshio dispersal route Borelis matsudai sp. nov. likely appeared in the southern and central Ryukyu Islands at least from the Chibanian (Middle Pleistocene). This species represents a marginal part of a population in significant contact with its ancestor (B. pulchra), which is widespread southward since the Oligocene (Philippines). With ongoing global warming possible occurrences of Borelis matsudai sp. nov. in northern Ryukyu Islands, where it has not yet been found, are expected. The Sekisei Lagoon represents, therefore, a biogeographical stepping stone relay station in northward migration of the shallow-water benthic organisms along the Kuroshio dispersal route
Paleobiogeographic patterns of a persistent monophyletic lineage: Lithophyllum pustulatum species group (Corallinaceae, Corallinales, Corallinophycidae, Rhodophyta).
No full textPaleobiogeographic patterns of a coralline red algal species group (Lithophyllum pustulatum) are assessed in order to draw back the origin (first appearance) of the group and its migrants
Disentangling biogeographical patterns through the integration of fossil data: Alveolinella quoyi in the western Indo-Pacific Warm Pool
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