Cosmopolitan Assemblage Research Articles

CELEBRATING DEATH AT THE SANCTUARY OF ORTHIA: A PROTHESIS SCENE, THE IVORY CORPUS AND RITUAL LANDSCAPES IN THE ARCHAIC PERIOD

The corpus of carved ivories from the sanctuary of Orthia at Sparta forms one of the most cosmopolitan assemblages from Archaic Laconia. One image within this corpus, however, has remained an anomaly: a mirror-image scene on two plaques showing three figures mourning a deceased male in the prothesis ritual. The puzzling nature of these plaques rests on the dearth of imagery elsewhere in Laconia from this period displaying the prothesis, unlike Attica. These images have been viewed as representing a mythical death or a commemoration of an actual death, tied to a period in Sparta's history when elite groups claimed power through ostentatious ritual, but their overall meaning within Orthia's sanctuary remains obscure. I argue, however, that these plaques are not anomalies within the ivory corpus, nor are they divorced from the broader ritual programme in Orthia's sanctuary – rather, the ivory corpus itself represents a unified composition that merged scenes showing ideal activities for Spartan citizens with heroic episodes from myth, geared towards the achievement of everlasting kléos. The semantics of these combined iconographies are clarified via comparison with cultic implements described in ancient literature alongside extant examples of multi-scene figural pottery from the seventh and sixth centuries. This paper thus highlights the mythological and ideological meanings of the prothesis plaques within the broader ivory corpus, and elucidates the role of complex figural iconographies in the elaboration of heroic ideals centred on Spartan citizens in this period.

Significance of floral axis and staminal features in tracing phylogeny of Cleome species

Taxonomic delimitation, phylogeny of Cleome L. species and relative closeness between three allied families, Capparaceae, Cleomaceae and Brassicaceae, are enigmatic and yet to be resolved comprehensively. The genus Cleome of Cleomaceae represents a cosmopolitan assemblage of species with wide variability in morphological features sharing morphological similarity with both Capparaceae and Brassicaceae. In the present study, floral-axis and staminal features, along with habit and leaf characters, were employed in tracing the phylogeny of Cleome species not explored earlier. The parameters proved unique in solving the phylogenetic puzzle of Cleome, allowing to speculate on the origin of woody and non-woody herbaceous species of Cleome from two separate species aggregates of Capparaceae (palmate-leaved Crateva aggregate and simple-leaved Capparis aggregate, respectively), also to establish phylogenetic linkage between three families, Capparaceae, Cleomaceae and Brassicaceae. Evolutionary changes were directed towards the gradual shortening and suppression of elongated floral axis to discoid thalamus, gradual reduction in the number and size of stamens, and flower size with habitual transformations from shrubby to herbaceous form. Cleome appeared as a connecting link between Capparaceae and Brassicaceae, and the interpretations derived showed significant concomitance with APG IV classification system.

To Staunchly “Remain a Reader” and build up a World Comradeship: Reflecting with Rabih Alameddine on World Literature

What is a classic? To what extent are books and book collections endangered goods? What is the role and meaning of literature and translation in times of hardship? In An Unnecessary Woman (2013), Rabih Alameddine addresses these questions, while also indirectly contesting traditional canonical practices based on rigid hierarchies and the logic of national and linguistic purity. Alameddine highlights the violence inscribed in the practices of book selection and canon formation. In doing so, he troubles received notions of the canon, the classics, and especially of world literature, offering an alternative conceptualization of this long-debated category as an intimate, cosmopolitan assemblage of worldly texts.

Cryptospores of Iapó formation: The first evidence of early land plants from Late Ordovician in Paraná Basin, Brazil.

Assemblages of cryptospores were reported and detailed for the first time from the Upper Ordovician from Brazil. These assemblages were recovered from diamictites and shales with dropstones of the Iapó Formation, Rio Ivaí Group, Paraná Basin. The analyzed sequence represents the Hirnantian glacial deposits containing well-preserved palynomorphs with low thermal maturity and low total organic carbon. The cryptospore assemblages comprise monads, dyads, permanent tetrads, and polyads, naked or enclosed in an envelope, totalizing 17 species. The associated marine palynomorphs consist of 12 species of acritarchs and prasinophycean algae which are not discussed in detail herein. It is noticied the occurrence of Tortotubus protuberans and abundant black fragments at the lowermost portion of diamictites. The Late Ordovician cosmopolitan assemblages of cryptospores corroborate the early radiation of the land plants in western Gondwana. These results contribute to a better knowledge of Late Ordovician in Brazil and more generally in South America.

Pioneer nannofossil assemblages from the initial transgression of the Niobrara seaway in the Turonian, San Juan Basin, New Mexico, USA

Abstract Nannofossils of the North American Late Cretaceous Western Interior Seaway have been extensively studied, but these investigations have primarily focused on the diverse communities of the Niobrara and Greenhorn sea-level highstands. We lack a firm understanding of the nature of early nannofossil communities from the initial stages of the transgression, and of how the diverse assemblages of the Coniacian–Santonian became established. We investigated nannofossils in a core from the San Juan Basin, New Mexico, with concentrated sampling across this transgression. We then compared nannofossil assemblages from the initial transgression of the seaway to the more established, cosmopolitan assemblages of the Niobrara highstand. The initial stages of transgression were characterized by unusual, low-diversity assemblages dominated by holococcoliths and seldom reported and previously undescribed species of hetero- and holococcoliths. Herein, we describe five new species and one new genus from these assemblages: Ahmuellerella frankiae sp. nov., Gartnerago waszczakii sp. nov., Orastrum schollei sp. nov., Pharus clarescopoli sp. nov., and Wisea sanjuanensis gen. et sp. nov. These initial assemblages transitioned to more cosmopolitan, higher-diversity assemblages, coincident with an unconformity that likely represents subaqueous erosion or prolonged non-deposition. Above this unconformity, the nannoplankton were abundant, diverse, and characterized by open-marine, cosmopolitan taxa that persisted through the Coniacian and Santonian. X-ray fluorescence data collected from the core show a high abundance of the detrital elements Al and Ti in the section, indicating substantial detrital clay input into the area, coincident with deposition of the holococcolith-dominated assemblages. The detrital influence lessened as cosmopolitan nannoplankton became more abundant in the area. We suggest that the initial holococcolith-rich assemblages are representative of a shallow-marine, potentially hyposaline, turbid or unstable environment. Such assemblages have been observed from the Late Turonian elsewhere in northern New Mexico and may represent typical pioneer nannofloras of the Late Cretaceous Western Interior marine transgressions. Our integrated investigation of nannofossils and X-ray fluorescence geochemistry adds to the meager knowledge base of pioneer nannofloral communities in the initial phases of continental marine transgression.

Ediacaran biozones identified with network analysis provide evidence for pulsed extinctions of early complex life

Rocks of Ediacaran age (~635–541 Ma) contain the oldest fossils of large, complex organisms and their behaviors. These fossils document developmental and ecological innovations, and suggest that extinctions helped to shape the trajectory of early animal evolution. Conventional methods divide Ediacaran macrofossil localities into taxonomically distinct clusters, which may represent evolutionary, environmental, or preservational variation. Here, we investigate these possibilities with network analysis of body and trace fossil occurrences. By partitioning multipartite networks of taxa, paleoenvironments, and geologic formations into community units, we distinguish between biostratigraphic zones and paleoenvironmentally restricted biotopes, and provide empirically robust and statistically significant evidence for a global, cosmopolitan assemblage unique to terminal Ediacaran strata. The assemblage is taxonomically depauperate but includes fossils of recognizable eumetazoans, which lived between two episodes of biotic turnover. These turnover events were the first major extinctions of complex life and paved the way for the Cambrian radiation of animals.

Film festivals as cosmopolitan assemblages

In this article, I seek to explore the use and development of the notion of cosmopolitanism within the context of film festivals. I will examine the specific case study of the Leicester Asian Film Festival from the perspective of an insider—as a Film Programmer and Associate Director of the event. The questions that I intend to answer are: what happens to our understanding of film festivals when we frame it through discourses of cosmopolitanism and borders and, conversely, what happens to our understanding of cosmopolitanism when we frame it through film festival studies? Accordingly, I will place cosmopolitanism in conversation with the developing literature on film festival studies. The aim is to offer an idea of film festivals as “cosmopolitan assemblage”, within a frame of fluidity, exchangeability and multiple functionalities (Deleuze and Guattari). In developing this concept, I will draw on Ulf Hannerz’s use of the term cosmopolitanism that includes being open to and involved with otherness. The aim is to theorise the idea of festivals as borders, and inspire new forms of consciousness and cultural competency applied to film festival programming.

Fatty acid trophic markers in Lake Baikal phytoplankton: A comparison of endemic and cosmopolitan diatom-dominated phytoplankton assemblages

Recent changes in phytoplankton community in Lake Baikal suggest the reduction in bloom of endemic diatoms takes place. How much these changes affect primary production remains unknown. Fatty acids are suitable biomarkers of the phytoplankton food quality. In our work we present the data of the qualitative and quantitative analysis of fatty acids (FA) in net samples of Lake Baikal phytoplankton. According to microscopic analysis of the samples the main phytoplankton groups were diatoms (Bacillarophyceae), golden algae (Chrysophyceae), green algae (Chlorophyceae), and Dinophytes (Dinophyceae). Visual quantification of cells showed that Synedra acus subsp. radians, Aulacoseira islandica, Synedra ulna, and Aulacoseira baicalensis were dominant diatom species. The first three species are cosmopolitan and the last one is endemic. Gas chromatography–mass spectrometry analysis revealed that the fatty acid biomarker values reflect changes in phytoplankton community structure in Lake Baikal. The trophic markers of the phytoplankton dominated by endemic A. baicalensis were higher compared to the phytoplankton dominated by cosmopolitan S. acus subsp. radians. The long-chain essential FA (LCEFA, %DW) and FA-based food quality index (FQI) for endemic assemblage were 1.85 and 0.75, while for the cosmopolitan assemblage −0.70 and 0.28, correspondingly. Our data suggest that reduction in bloom of endemic A. baicalensis may negatively affect the Lake Baikal ecosystem due to probable lower LCEFA production and, consequently, lower total productivity of the lake.

ESSENTIAL AND FIXED OIL CHEMICAL PROFILES OF Salvia aegyptiaca L. FLOWERS AND SEEDS

ABSTRACT The essential oil content in the flowers of Salvia aegyptiaca growing wild in south of Iran was found to be 0.1% (v/w). The essential oil was analyzed by GC and GC–MS. Ten constituents, representing 98.7 % of the flowers essential oil were identified. The major component of S. aegyptiaca flowers essential oil was identified as octane (60.7%). The fixed oil content and fatty acid composition of the seeds were also analyzed in order to determine their potential for human or animal consumption. The oil content in these edible seeds was found to be 16.2 %. The oil was analyzed by GC and GC/MS and twenty six components identified which constituted 84.6 % of the oil. The main compounds of the seeds oil were characterized as n-dodecane (23.9%), tetradecane (15.6%) and n-decane (10.5%). Keywords: Salvia aegyptiaca, Lamiaceae, Flowers, Essential oil, Seeds, Fixed oil e-mail: asgarpanah@iaups.ac.ir INTRODUCTION The largest genus of the Lamiaceae family, the genus Salvia L. represents an enormous and cosmopolitan assemblage of nearly 1000 species displaying remarkable variation. It has undergone marked species radiations in three regions of the world: Central and South America (500 spp.), Central Asia/Mediterranean (250 spp.) and Eastern Asia (90 spp.) [1]. Iran, particularly, is one of the centers of origin of the genus

ESSENTIAL AND FIXED OIL CHEMICAL COMPOSITIONS OF THE SEEDS FROM THE ENDEMIC SPECIES Salvia Sharifii RECH. F. & ESFAND

ABSTRACT The essential oil content in the seeds of Salvia sharifii growing wild in south of Iran was found to be 0.2% (v/w). The essential oil was analyzed by GC and GC–MS. Twenty eight constituents, representing 85.0 % of the seeds essential oil were identified. The major components of the S. sharifii seeds essential oil were identified as sclareol (21.9%) and n-decane (17.3%). The fixed oil content and fatty acid composition of the seeds were also analyzed in order to determine their potential for human or animal consumption. The oil content in these edible seeds was found to be 19.9 %. The oil was analyzed by GC and GC/MS and five fatty acids identified which constituted 88.0 % of the oil. The main fatty acids of the oil were characterized as linoleic acid (39.7%) and linolenic acid (36.7%). Keywords: Salvia sharifii, Lamiaceae, Seeds, Essential oil, Fixed oil INTRODUCTION The largest genus of the Lamiaceae family, the genus Salvia L. represents an enormous and cosmopolitan assemblage of nearly 1000 species displaying remarkable variation. It has undergone marked species radiations in three regions of the world: Central and South America (500 spp.), Central Asia/Mediterranean (250 spp.) and Eastern Asia (90 spp.) [1]. Iran, particularly, is one of the centers of origin of the genus

Morphological and Phylogenetic Characterization of New Gephyrocapsa Isolates Suggests Introgressive Hybridization in the Emiliania/Gephyrocapsa Complex (Haptophyta)

The coccolithophore genus Gephyrocapsa contains a cosmopolitan assemblage of pelagic species, including the bloom-forming Gephyrocapsa oceanica, and is closely related to the emblematic coccolithophore Emiliania huxleyi within the Noëlaerhabdaceae. These two species have been extensively studied and are well represented in culture collections, whereas cultures of other species of this family are lacking. We report on three new strains of Gephyrocapsa isolated into culture from samples from the Chilean coastal upwelling zone using a novel flow cytometric single-cell sorting technique. The strains were characterized by morphological analysis using scanning electron microscopy and phylogenetic analysis of 6 genes (nuclear 18S and 28S rDNA, plastidial 16S and tufA, and mitochondrial cox1 and cox3 genes). Morphometric features of the coccoliths indicate that these isolates are distinct from G. oceanica and best correspond to G. muellerae. Surprisingly, both plastidial and mitochondrial gene phylogenies placed these strains within the E. huxleyi clade and well separated from G. oceanica isolates, making Emiliania appear polyphyletic. The only nuclear sequence difference, 1bp in the 28S rDNA region, also grouped E. huxleyi with the new Gephyrocapsa isolates and apart from G. oceanica. Specifically, the G. muellerae morphotype strains clustered with the mitochondrial β clade of E. huxleyi, which, like G. muellerae, has been associated with cold (temperate and sub-polar) waters. Among putative evolutionary scenarios that could explain these results we discuss the possibility that E. huxleyi is not a valid taxonomic unit, or, alternatively the possibility of past hybridization and introgression between each E. huxleyi clade and older Gephyrocapsa clades. In either case, the results support the transfer of Emiliania to Gephyrocapsa. These results have important implications for relating morphological species concepts to ecological and evolutionary units of diversity.

Evidence for an African-Iberian mammal dispersal during the pre-evaporitic Messinian

The accurate timing of biogeographic dispersal can be determined by examining the age of fossiliferous strata on either side of a physical barrier. Here we show that African mammals migrated to Iberia and European mammals migrated to North Africa at the same time before isolation of the Mediterranean Sea during the Messinian. The fossil site of Venta del Moro (Spain) exhibits western Europe’s most complete vertebrate fauna for the latest Miocene. Its uniquely cosmopolitan assemblage is evidence of faunal dispersals from Africa and Asia to Europe during the latest Miocene glaciation. A preliminary paleomagnetic study suggested an age of 5.8 Ma for this site, but our expanded magnetostratigraphy dates the site at 6.23 Ma. In addition, we recalibrated the paleomagnetic age of the Librilla site (Spain) and the North Africa site of Afoud-1 (Morocco) using the Astronomical Tuned Neogene Time Scale. Our results show a two-way African-Iberian mammal dispersal just before 6.2 Ma. These new ages indicate that an ephemeral land corridor existed between the two continents 250 k.y. before the onset of the Messinian Salinity Crisis, reflecting a tentative initial isolation of the Mediterranean Sea. This corridor developed after tectonics closed the Betic Seaway at 6.3 Ma and during the intensification of the latest Miocene glaciation at 6.26 Ma, when water circulation in the Mediterranean became very restricted.

A new taxon of the genus Salvia (Lamiaceae) from Turkey

Salvia L., the largest genus of Lamiaceae, represents an enormous and cosmopolitan assemblage of nearly 1000 species displaying remarkable variation. It has undergone marked species radiations in three regions of the world: Central and South America (500 spp.), Central Asia/ Mediterranean (250 spp.) and Eastern Asia (90 spp.) (Walker et al. 2004). The latest comprehensive treatment for Salvia in Turkey, Hedge (1982a) recognised 87 species, one of them doubtful. Since 2005, as part of a revision of the genus in Turkey, the authors have described two new species (Ilcim et al. 2009, Celep & Dogan 2010), one new variety (Celep et al. 2009a) and two new records (Celep et al. 2009b, Kahraman et al. 2009). S. aucheri Benth. var. canescens Boiss. & Heldr. has been also raised to subspecies rank (Celep et al. in press). Moreover, two synonyms have been evaluated as valid species (Kahraman et al. 2010). During a field trip near Bozkir, South of Konya (C4, sensu Davis 1965) in the context of this revision, we encountered an unusual population of S. cadmica Boiss. within the area of its known population. The unusual specimens resemble S. smyrnaea Boiss. in terms of their calyx and corolla colour. Later on, similar unusual specimens were found in other populations of S. cadmica in South, West and Central Anatolia. The specimens were identified using the relevant literature (Boissier 1879, Hedge 1972, 1982a, 1982b, Pobedimova 1954) and compared with the types and other representative collections present at ANK, BM, E, G, GAZI, HUB, ISTE, ISTF, K and W herbaria. The objectives of this study are to present the taxonomic revison of S. cadmica and S. smyrnaea analysing their populations by means of field, herbarium and numerical taxonomic methods, to determine the key characters for distinguishing the taxa, to give their amended and expanded description, phenology, ecology and distribution, and to report their pollen and nutlet characteristics.

Wall ecology: A frontier for urban biodiversity and ecological engineering

Walls are extensive, ubiquitous urban ecosystems that can act as habitat for a range of different species and support non-standard cosmopolitan assemblages. Most investigations into wall ecology have focused on botanical surveys rather than testing hypotheses, but it is apparent that walls can be surprisingly diverse. They also have the potential to be ecologically engineered to encourage a greater diversity and range of species. This review considers the development of wall ecology, highlighting the key characteristics of walls that have been found to influence their ability to support species, with a focus on higher plants. It then examines the kinds of plant assemblages that are found on walls and the broader role of walls within urban biodiversity, before discussing the potential for ecological engineering of walls. Some progress has recently been made in the latter area with the installation of living walls and the physical engineering of wall materials, but much more needs to be done to effectively increase their physical complexity and habitat quality. Walls therefore represent a substantial potential (as well as existing) habitat within urban areas.

Global patterns of organic‐walled phytoplankton biodiversity during the late Silurian to earliest Devonian

Numerous environmental factors as well as oceanic circulation patterns and geographic constraints all contribute to the abundance, distribution, and diversity of present‐day marine phytoplankton assemblages. These same factors presumably affected the Paleozoic marine phytoplankton, which was dominated by organic‐walled acritarchs and prasinophytes. During the Late Silurian (Gorstian, Ludfordian, and Prídolf) and earliest Devonian (Lochkovian), important paleogeographic, paleooceanographic, and geochemical changes were occurring as well as major compositional changes and diversity fluctuations in the marine organic‐walled phytoplankton. Innovative morphologies appeared during the Late Silurian, in both low and high latitude assemblages, but with significant quantitative differences. This was followed by a turnover in assemblage composition during the Silurian/Devonian transition, and an initial radiation of new acritarch and prasinophyte taxa in the Early Devonian. Observed changes in total phytoplankton diversity during the Gorstian through earliest Lochkovian are based on organic‐walled microphytoplankton data derived from published and unpublished key stratigraphic sections where independent age control has been firmly established. These key sections are from: Missouri and Oklahoma, U.S.A. and western Newfoundland, Canada (Laurentia); Gotland, Sweden, and Podolia, Ukraine (Baltica); the Welsh Basin and Borderland (Avalonia); northern France and northern Spain (Armorica); and Libya in northern Africa, and Argentina and Bolivia, South America (Gondwana). Regional biodiversity changes for the organic‐walled microphytoplankton were determined for the warm low latitude areas (Baltica, Laurentia, and Avalonia) and temperate to cool higher latitude areas (northern and southern Gondwana). The Late Silurian‐earliest Devonian organic‐walled phytoplankton was divided into three major categories to facilitate comparison of compositional fluctuations, both within stratigraphic sections as well as between geographic areas. The three categories, based on overall morphology, are marine chlorophytes and prasinophytes, marine acritarchs, and nonmarine types, including coenobial forms. This triparate grouping is both broad and detailed enough to mark critical changes in both the phytoplankton assemblages, as well as the paleoenvironment. In general, high phytoplankton diversity peaks occurred during the Early and Late Gorstian in the warm low latitude areas, followed by varying fluctuations during the Ludfordian and Prídolí for both the warm low latitude and cool high latitude areas. An initial radiation of new phytoplankton taxa and the appearance of more cosmopolitan assemblages mark the beginning of the Lochkovian.

Palaeoenvironmental and palaeobiologic changes across the Barremian/Aptian boundary interval in the Tethys Realm, Mexico and Romania

Upper Barremian–lower Aptian rock sequences in northeast Mexico and the South Carpathians of Romania display palaeoenvironmental and palaeobiologic similarities. The upper Barremian deposits in both areas studied accumulated in shallow marine environments. A latest Barremian transgression was recorded only in Romania, where it is characterized by the prevalence of marly sequences that include mixed Tethyan and Boreal floras and faunas. In both study areas, late Barremian shallow-marine carbonate platforms were succeeded by deep-marine facies in the early Aptian. This was probably related to the early Aptian global sea-level rise. The Barremian/Aptian boundary in both areas is indicated approximately by the first occurrence of the foraminifer species Palorbitolina lenticularis, a bioevent that is coincident with the acme of the foraminifer group Orbitolina. In the early Aptian, Tethyan faunas and floras characteristic of the late Barremian were replaced by cosmopolitan assemblages, an event coincident with the first appearance in Romania of the ammonite genus Deshayesites.

Paleoecology of a groundwater outflow using siliceous microfossils

Paleoecological investigations of sediments deposited downstream of freshwater springs have the potential to reconstruct the environmental history of source aquifers and their catchments, thereby allowing for the study of long-term changes in these important hydrological systems. In an exploratory investigation, a 76-cm sediment column was obtained from a spring bed in Scarborough, southern Ontario, Canada. The column represents about 160 years of accumulated sediment. Siliceous microfossils, including diatoms, chrysophyte cysts, phytoliths and plates of testate amoebae (Rhizopoda), were identified and enumerated. Over the ~160-year period, siliceous remains track a gradual transition from a slow river environment in the early 1800s to a spring-fed pond environment by the late-1800s, hurricane-induced flooding, and the eventual slowing and drying of the spring in the latter half of the twentieth century. Basal, pre-settlement sediments contain a cosmopolitan assemblage of diatom taxa and testacean plates of the genus Lesquereusia. Between ~1880 and ~1954, fossils of aquatic species occur only in trace amounts, indicating increased deposition of clastic material and poor conditions for survival, but unbroken microfossils indicate that preservation of opaline remains was not a problem. Despite low concentrations of microfossils in this interval, chrysophyte and testacean survival was favoured over diatoms. In 1954, a thick layer of sediment was deposited by hurricane-induced flooding, confirmed by high phytolith concentrations from terrestrial sources. Since ~1960, epiphytic diatoms, reflecting dense macrophyte growth and higher productivity, dominate the diatom assemblage. Some of the recent diatom taxa are also salinity-tolerant, reflecting possible groundwater salinification. Chrysophyte cysts are relatively abundant at the top of the sediment column, but recent concentrations are lower than pre-settlement levels, likely reflecting an increased nutrient load. Recent increases in vegetation in and around the spring are also inferred by high concentrations of testacean plates and phytoliths. These paleoecological data match historical records and data from previous investigations of fossil aquatic insect larvae. These approaches show promise for relating changes in siliceous microfossils to human impacts and natural changes in spring habitats, their catchments and the quality of groundwater.

Sedimentary patterns across the Lower–Middle Cambrian transition in the Esla nappe (Cantabrian Mountains, northern Spain)

Abstract In the carbonate platforms of the western Gondwana margin, the extinction recorded at the Lower–Middle Cambrian boundary is accompanied by a profound change in the style of carbonate deposition. The Lancara Formation of the Esla nappe (Cantabrian Mountains, northern Spain) contains a distinct sedimentary turnover due to a combination of tectonism, eustatic fluctuations, and immigration and colonization of new benthic communities, such as the youngest archaeocyathan assemblage of the entire Iberian Peninsula. During latest Early Cambrian times, a regressive trend is recorded in the Lancara Formation. This regression was recorded on a peritidal-dominant, homoclinal ramp that is topped by a tectonically induced discontinuity (D1). The latter surface marks the beginning of a last prograding, regressive tendency recorded on an intra-shelf ramp with ooidal/bioclastic shoals protecting archaeocyathan-microbial patch reefs. The overlying discontinuity (D2) corresponds to a major erosive unconformity, which coincides with the Lower–Middle Cambrian boundary in the Cantabrian Mountains. The subsequent, long-term, earliest Middle Cambrian rise in relative sea-level allowed deposition of low-relief, bioclastic shoals bearing a diverse and cosmopolitan assemblage of benthic fauna. Finally, the previous evolution is bounded by a third discontinuity (D3), which marks the beginning of a rhythmic sedimentation indicative of a major phase of tectonic breakdown and drowning of platforms recognised throughout southwestern Europe. Two associations of calcimicrobes occur in the latest Early Cambrian regressive trend of the Lancara Formation: (i) Proaulopora and Subtiflora are identified in peritidal, high-energy settings, lacking self-supported structures, whereas (ii) intergrowths of Epiphyton, Renalcis and Girvanella encrusted branching colonies and solitary archaeocyaths in protected (back-shoal) patch reefs. The latest Early Cambrian regression is correlated in southwestern Europe in both siliciclastic (Iberian Chains and Ossa–Morena) and carbonate-dominant platforms (Cantabrian Mountains, Montagne Noire and Sardinia). Its tops are recognised as diachronous unconformities ranging in age from early Bilbilian to the Bilbilian–Leonian or Lower–Middle Cambrian boundary.

Paléogéographie des algues calcaires marines carbonifères

Three marine algal microfloral realms are recognized in the Carboniferous: (i) a Tethyan flora with numerous Dasycladales and high endemism, (ii) a North American flora with some Dasycladales and fairly low endemism, and (iii) an Arctic flora composed of Dasycladales in low numbers and with cosmopolitan assemblages. These three phytochores are interconnected by a high number of "cosmopolitan" genera and species. However "transatlantic" exchanges are limited. The floras of the American exotic terranes (Peratrovich type) have some tethyan affinities but are basically cosmopolitan.