scholarly journals Photosymbiosis and the expansion of shallow-water corals

2016 ◽  
Vol 2 (11) ◽  
pp. e1601122 ◽  
Author(s):  
Katarzyna Frankowiak ◽  
Xingchen T. Wang ◽  
Daniel M. Sigman ◽  
Anne M. Gothmann ◽  
Marcelo V. Kitahara ◽  
...  
Keyword(s):  
Shallow Water ◽  
Nitrogen Isotopes ◽  
Late Triassic ◽  
Shallow Marine ◽  
Tethys Sea ◽  
Coral Skeletons ◽  
Main Driver ◽  
Ecological Success ◽  
Key Driver ◽  
Modern Reef

Roughly 240 million years ago (Ma), scleractinian corals rapidly expanded and diversified across shallow marine environments. The main driver behind this evolution is uncertain, but the ecological success of modern reef-building corals is attributed to their nutritional symbiosis with photosynthesizing dinoflagellate algae. We show that a suite of exceptionally preserved Late Triassic (ca. 212 Ma) coral skeletons from Antalya (Turkey) have microstructures, carbonate13C/12C and18O/16O, and intracrystalline skeletal organic matter15N/14N all indicating symbiosis. This includes species with growth forms conventionally considered asymbiotic. The nitrogen isotopes further suggest that their Tethys Sea habitat was a nutrient-poor, low-productivity marine environment in which photosymbiosis would be highly advantageous. Thus, coral-dinoflagellate symbiosis was likely a key driver in the evolution and expansion of shallow-water scleractinians.

scholarly journals A review of Palaeozoic and Mesozoic tetrapods from Greenland

2018 ◽  
Vol 66 ◽  
pp. 21-46 ◽  
Author(s):  
Marco Marzola ◽  
Octávio Mateus ◽  
Jesper Milàn ◽  
Lars B. Clemmensen
Keyword(s):  
Late Jurassic ◽  
Early Jurassic ◽  
Late Carboniferous ◽  
Late Triassic ◽  
Late Devonian ◽  
Early Triassic ◽  
Shallow Marine ◽  
East Greenland ◽  
Marine Deposits ◽  
Theropod Dinosaurs

This article presents a synthesis of Palaeozoic and Mesozoic fossil tetrapods from Greenland, including an updated review of the holotypes and a new photographic record of the main specimens. All fossil tetrapods found are from East Greenland, with at least 30 different known taxa: five stem tetrapods (Acanthostega gunnari, Ichthyostega eigili, I. stensioi, I. watsoni, and Ymeria denticulata) from the Late Devonian of the Aina Dal and Britta Dal Formations; four temnospondyl amphibians (Aquiloniferus kochi, Selenocara groenlandica, Stoschiosaurus nielseni, and Tupilakosaurus heilmani) from the Early Triassic of the Wordie Creek Group; two temnospondyls (Cyclotosaurus naraserluki and Gerrothorax cf. pulcherrimus), one testudinatan (cf. Proganochelys), two stagonolepids (Aetosaurus ferratus and Paratypothorax andressorum), the eudimorphodontid Arcticodactylus, undetermined archosaurs (phytosaurs and both sauropodomorph and theropod dinosaurs), the cynodont Mitredon cromptoni, and three mammals (Haramiyavia clemmenseni, Kuehneotherium, and cf. ?Brachyzostrodon), from the Late Triassic of the Fleming Fjord Formation; one plesiosaur from the Early Jurassic of the Kap Stewart Formation; one plesiosaur and one ichthyosaur from the Late Jurassic of the Kap Leslie Formation, plus a previously unreported Late Jurassic plesiosaur from Kronprins Christian Land. Moreover, fossil tetrapod trackways are known from the Late Carboniferous (morphotype Limnopus) of the Mesters Vig Formation and at least four different morphologies (such as the crocodylomorph Brachychirotherium, the auropodomorph Eosauropus and Evazoum, and the theropodian Grallator) associated to archosaurian trackmakers are known from the Late Triassic of the Fleming Fjord Formation. The presence of rich fossiliferous tetrapod sites in East Greenland is linked to the presence of well-exposed continental and shallow marine deposits with most finds in terrestrial deposits from the Late Devonian and the Late Triassic.

Taxonomic affinities and paleogeography of Stromatomorpha californica Smith, a distinctive Upper Triassic reef-adapted demosponge

2009 ◽  
Vol 83 (5) ◽  
pp. 783-793 ◽  
Author(s):  
B. Senowbari-Daryan ◽  
G. D. Stanley
Keyword(s):  
North America ◽  
Shallow Water ◽  
Type Species ◽  
Upper Triassic ◽  
Northern Calcareous Alps ◽  
Late Triassic ◽  
Separate Species ◽  
Northern Calcareous ◽  
Siliceous Spicules ◽  
Horizontal Layers

Stromatomorpha californica Smith is a massive, calcified, tropical to subtropical organism of the Late Triassic that produced small biostromes and contributed in building some reefs. It comes from the displaced terranes of Cordilleran North America (Eastern Klamath terrane, Alexander terrane, and Wrangellia). This shallow-water organism formed small laminar masses and sometimes patch reefs. It was first referred to the order Spongiomorphidae but was considered to be a coral. Other affinities that have been proposed include hydrozoan, stomatoporoid, sclerosponge, and chambered sponge. Part of the problem was diagenesis that resulted in dissolution of the siliceous spicules and/or replaced them with calcite. Well-preserved dendroclone spicules found during study of newly discovered specimens necessitate an assignment of Stromatomorpha californica to the demosponge order Orchocladina Rauff. Restudy of examples from the Northern Calcareous Alps extends the distribution of this species to the Tethys, where it was an important secondary framework builder in Upper Triassic (Norian-Rhaetian) reef complexes. Revisions of Stromatomorpha californica produce much wider pantropical distribution, mirroring paleogeographic patterns revealed for other tropical Triassic taxa. Review of Liassic material from the Jurassic of Morocco, previously assigned to Stromatomorpha californica Smith var. columnaris Le Maitre, cannot be sustained. Species previously included in Stromatomorpha are: S. stylifera Frech (type species, Rhaetian), S. actinostromoides Boiko (Norian), S. californica Smith (Norian), S. concescui Balters (Ladinian-Carnian), S. pamirica Boiko (Norian), S. rhaetica Kühn (Rhaetian), S. stromatoporoides Frech, and S. tenuiramosa Boiko (Norian). Stromatomorpha rhaetica Kühn described from the Rhaetian of Vorarlberg, Austria shows no major difference from S. californica. An example described as S. oncescui Balters from the Ladinian-Carnian of the Rarau Mountains, Romania, is very similar to S. californica in exhibiting similar spicule types. However, because of the greater distance between individual pillars, horizontal layers, and the older age, S. oncescui is retained as a separate species. The net-like and regular skeleton of Spongiomorpha sanpozanensis Yabe and Sugiyama, from the Upper Triassic of Sambosan (Tosa, Japan), suggests a closer alliance with Stromatomorpha, and this taxon possibly could be the same as S. californica.

A Pilot Study on Zinc Isotopic Compositions in Shallow‐Water Coral Skeletons

2020 ◽  
Vol 21 (11) ◽  
Author(s):  
Hangfang Xiao ◽  
Wenfeng Deng ◽  
Gangjian Wei ◽  
Jiubin Chen ◽  
Xinqing Zheng ◽  
...  
Keyword(s):  
Pilot Study ◽  
Shallow Water ◽  
Coral Skeletons ◽  
Isotopic Compositions ◽  
Water Coral

scholarly journals Fossil and modern sponge fauna of southern Australia and adjacent regions compared: interpretation, evolutionary and biogeographic significance of the late Eocene ‘soft’ sponges

2016 ◽  
Vol 85 (1) ◽  
pp. 13-35 ◽  
Author(s):  
Magdalena Łukowiak
Keyword(s):  
New Zealand ◽  
Shallow Water ◽  
Environmental Context ◽  
Late Eocene ◽  
Shallow Marine ◽  
Marine Communities ◽  
Shallow Water Species ◽  
Water Species

The late Eocene ‘soft’ sponge fauna of southern Australia is reconstructed based on disassociated spicules and is used to interpret the paleoecology and environmental context of shallow marine communities in this region. The reconstructed sponge association was compared with coeval sponge assemblages from the Oamaru Diatomite, New Zealand, and with the modern ‘soft’ sponge fauna of southern coastal of Australia. Based on the predominance of shallow- and moderately shallow-water species, the late Eocene assemblage is interpreted to have inhabited waters depths of about 100 m. This contrast with the spicule assemblage from New Zealand, which characterized deeper waters based on the presence of numerous strictly deepwater sponge taxa, and the absence of spicules of shallow-water demosponges represented in the Australian material. The southern Australian Eocene sponge assemblages have clear Tethyan affinities evidenced by the occurrence of sponges known today from diverse regions. This distribution suggests much wider geographical ranges of some sponge taxa during the Eocene. Their present distributions may be relictual. The modern sponge fauna inhabiting southern Australian waters shows only moderate differences from these of the late Eocene. Differences are more pronounced at lower taxonomic levels (family and genus).

scholarly journals Lithostratigraphy and biostratigraphy of the Lower Carboniferous (Mississippian) carbonates of the southern Askrigg Block, North Yorkshire, UK

2016 ◽  
Vol 154 (2) ◽  
pp. 305-333 ◽  
Author(s):  
C. N. WATERS ◽  
P. CÓZAR ◽  
I. D. SOMERVILLE ◽  
R. B. HASLAM ◽  
D. MILLWARD ◽  
...  
Keyword(s):  
Shallow Water ◽  
Sea Level ◽  
Carbonate Ramp ◽  
Fault System ◽  
Lower Carboniferous ◽  
Shallow Marine ◽  
Sea Level Fluctuations ◽  
Algal Assemblages ◽  
Lower Palaeozoic ◽  
Southern Flank

AbstractA rationalized lithostratigraphy for the Great Scar Limestone Group of the southeast Askrigg Block is established. The basal Chapel House Limestone Formation, assessed from boreholes, comprises shallow-marine to supratidal carbonates that thin rapidly northwards across the Craven Fault System, onlapping a palaeotopographical high of Lower Palaeozoic strata. The formation is of late Arundian age in the Silverdale Borehole, its northernmost development. The overlying Kilnsey Formation represents a southward-thickening and upward-shoaling carbonate development on a S-facing carbonate ramp. Foraminiferal/algal assemblages suggest a late Holkerian and early Asbian age, respectively, for the uppermost parts of the lower Scaleber Force Limestone and upper Scaleber Quarry Limestone members, significantly younger than previously interpreted. The succeeding Malham Formation comprises the lower Cove Limestone and upper Gordale Limestone members. Foraminiferal/algal assemblages indicate a late Asbian age for the formation, contrasting with the Holkerian age previously attributed to the Cove Limestone. The members reflect a change from a partially shallow-water lagoon (Cove Limestone) to more open-marine shelf (Gordale Limestone), coincident with the onset of marked sea-level fluctuations and formation of palaeokarstic surfaces with palaeosoils in the latter. Facies variations along the southern flank of the Askrigg Block, including an absence of fenestral lime-mudstone in the upper part of the Cove Limestone and presence of dark grey cherty grainstone/packstone in the upper part the Gordale Limestone are related to enhanced subsidence during late Asbian movement on the Craven Fault System. This accounts for the marked thickening of both members towards the Greenhow Inlier.

Batocrinidae (Crinoidea) from the Lower Mississippian (lower Viséan) Fort Payne Formation of Kentucky, Tennessee, and Alabama: systematics, geographic occurrences, and facies distribution

2018 ◽  
Vol 92 (4) ◽  
pp. 681-712
Author(s):  
William I. Ausich ◽  
Elizabeth C. Rhenberg ◽  
David L. Meyer
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Dominant Species ◽  
Carbonate Facies ◽  
Shallow Marine ◽  
First Time ◽  
Water Carbonate ◽  
Shallow Water Carbonate ◽  
Water Facies ◽  
Mixed Carbonate

AbstractThe Batocrinidae are characteristic faunal elements in Lower Mississippian shallow-marine settings in North America. Recent delineation of objectively defined genera allows a reexamination of batocrinid species and their distribution in the Fort Payne Formation (early Viséan, late Osagean), a well-studied array of carbonate and siliciclastic facies. The Fort Payne batocrinid fauna has 14 species assigned to six genera, plus hybrid specimens.Magnuscrinus spinosus(Miller and Gurley, 1895a) is reassigned to its original placement inEretmocrinus. Hybrid specimens (Ausich and Meyer, 1994) are regarded asEretmocrinus magnificus×Eretmocrinus spinosus.Macrocrinus casualisis the dominant species ofMacrocrinusin the Fort Payne, andM.mundulusandM.strotobasilarisare recognized in the Fort Payne Formation for the first time.Magnuscrinus cumberlandensisn. sp. is named, 13 species are designated as junior synonyms, the name for the hybrid specimens is changed toEretmocrinus magnificus×Eretmocrinus spinosus, and the previous occurrences of two species in the Fort Payne are rejected. The Eastern Interior Seaway was a mixed carbonate-siliciclastic setting with both shallow- and deep-water epicontinental sea facies ranging from relatively shallow autochthonous green shales to deep-water turbidite facies.Dizygocrinuswas restricted to shallow-water carbonate and siliciclastic facies,Eutrochocrinuswas restricted to shallow-water carbonate facies, andMagnuscrinuswas restricted to deep-water facies. Species distributions varied fromAbatocrinus steropes,Alloprosallocrinus conicus,Macrocrinus mundulus, andUperocrinus nashvillae, which occurred throughout the Eastern Interior Seaway, to species that were restricted to a single facies.Eretmocrinus magnificus,Alloprosallocrinus conicus, andUperocrinus robustuswere the dominant batocrinids in the Fort Payne Formation.UUID:http://zoobank.org/703aafd8-4c73-4edc-9870-e2356e2d28b8

Neotethyan evolution of eastern Greece (Pagondas Mélange, Evia island) inferred from radiolarian biostratigraphy and the geochemistry of associated extrusive rocks

2001 ◽  
Vol 138 (3) ◽  
pp. 345-363 ◽  
Author(s):  
TANIEL DANELIAN ◽  
ALASTAIR H. F. ROBERTSON
Keyword(s):  
Shallow Water ◽  
Carbonate Platform ◽  
Ocean Basin ◽  
Passive Margin ◽  
Late Triassic ◽  
Geochemical Data ◽  
Chemical Compositions ◽  
Similar Chemical ◽  
Thrust Sheets ◽  
Age Range

This paper presents new radiolarian biostratigraphic and igneous/metamorphic geochemical data for a Mesozoic volcanic–sedimentary mélange on the island of Evia (Euboea or Evvoia), eastern Greece. This mélange includes dismembered thrust sheets and blocks of radiolarian chert and basalt. Biostratigraphic age data show that radiolarites interbedded with basalt-derived, coarse clastic sediments near the base of a coherent succession were deposited in Middle and Late Triassic time (Late Ladinian–Carnian, Norian?). Geochemical evidence shows that associated extrusive rocks, of inferred Triassic age, range from ‘enriched’ alkaline basalts, to ‘transitional’ basalts, and more ‘depleted’ mid-ocean ridge-type basalts. Amphibolite facies meta-basalts from the metamorphic sole of the over-riding Evia ophiolite exhibit similar chemical compositions. Both the basalts and the meta-basalts commonly show an apparent subduction-related influence (e.g. relative Nb depletion) that may have been inherited from a previous subduction event in the region. The basalts are interpreted to have erupted during Middle–Late Triassic time (Late Ladinian–Carnian), related to initial opening of a Neotethyan ocean basin adjacent to a rifted continental margin. Radiolarites located stratigraphically higher in the coherent succession studied are dated as Middle Jurassic (Late Bathonian–Early Callovian). Similar-aged radiolarites are depositionally associated with ophiolitic rocks (including boninites), in some other areas of Greece and Albania. During initial ocean basin closure (Bajocian–Bathonian) the adjacent shallow-water carbonate platform (Pelagonian zone) disintegrated to form basins in which siliceous sediments were deposited and highs on which shallow-water carbonates continued to accumulate. This facies differentiation is seen as a response to crustal flexure as the Neotethyan ocean began to close. The over-riding Pagondas Mélange and other similar units in the region are interpreted as accretionary prisms related to subduction of Neotethyan oceanic crust in Middle–Late Jurassic time. These mélanges were emplaced, probably diachronously during Oxfordian–Kimmeridgian time, when the passive margin collapsed, creating a foredeep ahead of advancing thrust sheets of mélange and ophiolites.

The stratigraphy of the Nicola Group in the Hedley district, British Columbia, and the chemistry of its intrusions and Au skarns

1996 ◽  
Vol 33 (8) ◽  
pp. 1105-1126 ◽  
Author(s):  
G. E. Ray ◽  
I. C. L. Webster ◽  
G. L. Dawson
Keyword(s):  
British Columbia ◽  
Oxidation State ◽  
Sedimentary Facies ◽  
Island Arc ◽  
Quartz Diorite ◽  
Late Triassic ◽  
Nickel Plate ◽  
Shallow Marine ◽  
Tectonically Active ◽  
Volcaniclastic Rocks

The Nicola Group at Hedley, British Columbia, is a late Carnian to late Norian (Late Triassic) sequence of calcareous sedimentary and arc-related volcaniclastic rocks. It was deposited on a tectonically active paleoslope that marked either the rifted eastern margin of the shallow-marine Nicola basin or the faulted edge of an intrabasinal platform. The lower part of the Nicola Group comprises a succession of four essentially coeval sedimentary facies. From east to west across the district, these are informally named the thin (approx. 200 m), shallow-marine, limestone-dominant French Mine formation; the thicker, calcareous siltstone-dominant Hedley and Chuchuwayha formations in the central part of the district; and the thick (up to 2200 m), deeper water and argillite-dominant Stemwinder formation. These facies are all blanketed by the Whistle formation, a 1200 m thick unit of basaltic tuff and tuffaceous sediment whose base is marked by a gravity-slide megabreccia, the Copperfield breccia. The Nicola arc at Hedley was associated with two plutonic episodes. Oldest are the Hedley intrusions, which are related to economic Au skarns, including the Nickel Plate deposit, which has produced over 71 t of gold from 13.4 Mt of ore. The Hedley intrusions are similar in composition (quartz gabbro to quartz diorite) and overall metaluminous chemistry to other island-arc-generated plutons related to many Cu and Fe skarns in British Columbia, although they are less evolved. They also differ in having lower Fe2O3/FeO ratios (avg. 0.23), indicating a reduced oxidation state, and higher Ba/La and Sc/Nb ratios. A slightly younger plutonic episode produced the 193 Ma (Early Jurassic) Bromley batholith and the 194 Ma Mount Riordan stock; the latter is associated with the Mount Riordan (Crystal Peak) industrial garnet skarn. Gold skarns are preferentially developed in areas where the Hedley intrusions cut the Hedley and French Mine formations. The Au skarn ore is marked by anomalous As, Bi, Te, and Co values, and by high pyrrhotite/pyrite and pyroxene/garnet ratios. It is distinct from the ore of Fe, Cu, Mo, Pb–Zn, W, and Sn skarns by its very low Cu/Au, Zn/Au, and Ag/Au ratios (avg. 97, 18, and 12, respectively).

COMPARATIVE TAPHONOMY OF DEEP-SEA AND SHALLOW-MARINE ECHINOIDS OF THE GENUS ECHINOCYAMUS

Palaios ◽  
2020 ◽  
Vol 35 (10) ◽  
pp. 403-420
Author(s):  
TOBIAS B. GRUN ◽  
MORANA MIHALJEVIĆ ◽  
GREGORY E. WEBB
Keyword(s):  
Shallow Water ◽  
Deep Sea ◽  
Model Organism ◽  
Polar Regions ◽  
Shallow Marine ◽  
Apical System ◽  
Distribution Ranges ◽  
Long Time ◽  
And Function ◽  
The Tropics

ABSTRACT The infaunal living clypeasteroid echinoid genus Echinocyamus is considered a model organism for various ecological and paleontological studies since its distribution ranges from the polar regions to the tropics, and from shallow-marine settings to the deep-sea. Deep-sea analyses of this genus are rare, but imperative for the understanding and function of these important ecosystems. During the 2012 Southern Surveyor expedition, 35 seamounts off the east coast of Australia were dredged in depths greater than 800 m. Of these, six dredges contained a total of 18 deep-sea Echinocyamus tests. The tests have been analyzed for taphonomic alterations including abrasion patterns, macro-borings, micro-borings, depressions on the test, test staining, test filling, encrustation, and fragmentation. Findings are interpreted in the context of the deep-sea setting and are compared to Echinocyamus samples from shallow-water environments. Results show that abrasion in deep-sea environments is generally high, especially in ambulacral and genital pores indicating that tests can persist for a long time on the seafloor. This contrasts with shallow-water Echinocyamus that show lower abrasion due to early test destruction. Macro-borings are present as single or paired holes with straight vertical profiles resembling Lithophaga borings. Micro-borings are abundant and most likely the result of sponge or fungal activity. Depressions on the tests, such as scars or pits, are likely the result of trauma or malformation during ontogeny. Test staining is common, but variable, and is associated with FE/Mn oxidation and authigenic clays based on elemental analyses. Test filling occurs as loose or lithified sediment. Encrustation is present in the form of rudimentary crusts and biofilms. No macro-organisms were found on the tests. Biofilm composition differs from shallow-water environments in that organisms captured in the biofilm reflect aphotic conditions or sedimentation of particles from higher in the water column (e.g., coccoliths). Fragmentation is restricted to the apical system and pore regions. Results of this first comparative study on deep-sea Echinocyamus from Australian seamounts show that the minute tests can survive for a long time in these settings and undergo environmental specific taphonomic processes reflected in various taphonomic alterations.

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