scholarly journals Morpho-molecular diversity and evolutionary analyses suggest hidden life styles in Spumellaria (Radiolaria)

2020 ◽  
Author(s):  
Miguel M. Sandin ◽  
Tristan Biard ◽  
Sarah Romac ◽  
Luis O’Dogherty ◽  
Noritoshi Suzuki ◽  
...  
Keyword(s):  
Fossil Record ◽  
Morphological Characteristics ◽  
Radial Symmetry ◽  
Global Ocean ◽  
Marker Genes ◽  
Environmental Reconstruction ◽  
Taxonomic Rank ◽  
Middle Cambrian ◽  
Life Styles ◽  
Comprehensive Classification

AbstractSpumellaria (Radiolaria, Rhizaria) are holoplanktonic amoeboid protists, ubiquitous and abundant in the global ocean. Their silicified skeleton preserves very well in sediments displaying an excellent fossil record, from the early middle Cambrian (ca. 509-521 Ma), extremely valuable for paleo-environmental reconstruction studies. Spumellaria are tedious to maintain in laboratory conditions preventing an accurate perception of their extant diversity and ecology in today’s oceans, most of which being inferred from sediment records. This study represents an integrated and comprehensive classification of Spumellaria based on the combination of ribosomal taxonomic marker genes (rDNA) and morphological characteristics. In contrast to established taxonomic knowledge, we demonstrate that symmetry of the skeleton takes more importance than internal structures at high taxonomic rank classification. Such reconsideration allows gathering different morphologies with concentric structure and a spherical or radial symmetry believed to belong to other Radiolaria orders from the fossil record, as for some Entactinaria families. Results obtained in this study suggest the existence of new Spumellaria diversity at early diverging positions, in which a non-bearing skeleton organism lives within shelled ones. Using fossil calibrated molecular clock we estimated the origin of Spumellaria in the middle Cambrian (ca. 515 Ma), in agreement with the appearance of the first radiolarian representatives in the fossil record. The morpho-molecular and evolutionary framework established herein allows a direct connection between living specimens and fossil morphologies from the Cambrian, bringing both a standpoint for future molecular environmental surveys and a better understanding for paleo-environmental reconstruction studies.

scholarly journals Time calibrated morpho-molecular classification of Nassellaria (Radiolaria)

2018 ◽  
Author(s):  
Miguel M. Sandin ◽  
Loic Pillet ◽  
Tristan Biard ◽  
Camille Poirier ◽  
Estelle Bigeard ◽  
...  
Keyword(s):  
Fossil Record ◽  
Phylogenetic Analyses ◽  
Molecular Ecology ◽  
Morphological Characteristics ◽  
Molecular Classification ◽  
Marker Genes ◽  
Microscopy Imaging ◽  
Worldwide Distribution ◽  
Internal Structures

AbstractNassellaria are marine radiolarian protists belonging to the Rhizaria lineage. Their skeleton, made of opaline silica, exhibit an excellent fossil record, extremely valuable in micro-paleontological studies for paleo-environmental reconstruction. Yet, to date very little is known about the extant diversity and ecology of Nassellaria in contemporary oceans, and most of it is inferred from their fossil record. Here we present an integrative classification of Nassellaria based on taxonomical marker genes (18S and 28S ribosomal DNA) and morphological characteristics obtained by optical and scanning electron microscopy imaging. Our phylogenetic analyses distinguished 11 main morpho-molecular clades relying essentially on the overall morphology of the skeleton and not on internal structures as previously considered. Using fossil calibrated molecular clock we estimated the origin of Nassellaria among radiolarians primitive forms in the Devonian (ca. 420 Ma), that gave rise to living nassellarian groups in the Triassic (ca. 250 Ma), during the biggest diversification event over their evolutionary history. This morpho-molecular framework provides both a new morphological classification easier to identify under light microscopy and the basis for future molecular ecology surveys. Altogether, it brings a new standpoint to improve our scarce understanding of the ecology and worldwide distribution of extant nassellarians.

Early radiation of echinoderms

1997 ◽  
Vol 3 ◽  
pp. 205-224 ◽  
Author(s):  
James Sprinkle ◽  
Thomas E. Guensburg
Keyword(s):  
Mass Extinction ◽  
Fossil Record ◽  
Early Paleozoic ◽  
Soft Substrate ◽  
Middle Cambrian ◽  
Middle Ordovician ◽  
Late Cambrian ◽  
Low Diversity ◽  
Early Radiation ◽  
Ways Of Life

Echinoderms underwent a major two-part radiation that produced all of the major groups found in the fossil record between the Early Cambrian and the Middle Ordovician. A small initial radiation in the Early and Middle Cambrian produced about nine classes containing low-diversity members of the Cambrian Evolutionary Fauna. These were characterized by primitive morphology, simple ambulacral feeding structures, and the early development of a multiplated stalk or stem for attachment to skeletal fragments on a soft substrate. Several groups became extinct at the end of the Middle Cambrian, leaving the Late Cambrian as a gap of very low diversity in the fossil record of echinoderms with only four classes preserved and very few occurrences of complete specimens, mostly associated with early hardgrounds. The survivors from this interval re-expanded in the Early Ordovician and were joined by many newly evolved groups to produce a much larger radiation of more advanced, diverse, and successful echinoderms representing the Paleozoic Evolutionary Fauna on both hard and soft substrates. At least 17 classes were present by the Middle Ordovician, the all-time high point for echinoderm class diversity, and nearly all of the major ways-of-life (except for deep infaunal burrowing) had been developed. With the rise to dominance of crinoids, many less successful or archaic groups did not survive the Middle Ordovician, and echinoderm class diversity dropped further because of the mass extinction at the end of the Ordovician. This weeding-out process of other less-successful echinoderm groups continued throughout the rest of the Paleozoic, and only five classes of echinoderms have survived to the Recent from this early Paleozoic radiation.

scholarly journals Debris-carrying camouflage among diverse lineages of Cretaceous insects

2016 ◽  
Vol 2 (6) ◽  
pp. e1501918 ◽  
Author(s):  
Bo Wang ◽  
Fangyuan Xia ◽  
Michael S. Engel ◽  
Vincent Perrichot ◽  
Gongle Shi ◽  
...  
Keyword(s):  
Fossil Record ◽  
Morphological Characteristics ◽  
Early Evolution ◽  
Behavioral Repertoire ◽  
Wood Fibers ◽  
Morphological Adaptations ◽  
Evolutionary Success ◽  
High Degree ◽  
Insect Assemblage ◽  
Insight Into

Insects have evolved diverse methods of camouflage that have played an important role in their evolutionary success. Debris-carrying, a behavior of actively harvesting and carrying exogenous materials, is among the most fascinating and complex behaviors because it requires not only an ability to recognize, collect, and carry materials but also evolutionary adaptations in related morphological characteristics. However, the fossil record of such behavior is extremely scarce, and only a single Mesozoic example from Spanish amber has been recorded; therefore, little is known about the early evolution of this complicated behavior and its underlying anatomy. We report a diverse insect assemblage of exceptionally preserved debris carriers from Cretaceous Burmese, French, and Lebanese ambers, including the earliest known chrysopoid larvae (green lacewings), myrmeleontoid larvae (split-footed lacewings and owlflies), and reduviids (assassin bugs). These ancient insects used a variety of debris material, including insect exoskeletons, sand grains, soil dust, leaf trichomes of gleicheniacean ferns, wood fibers, and other vegetal debris. They convergently evolved their debris-carrying behavior through multiple pathways, which expressed a high degree of evolutionary plasticity. We demonstrate that the behavioral repertoire, which is associated with considerable morphological adaptations, was already widespread among insects by at least the Mid-Cretaceous. Together with the previously known Spanish specimen, these fossils are the oldest direct evidence of camouflaging behavior in the fossil record. Our findings provide a novel insight into early evolution of camouflage in insects and ancient ecological associations among plants and insects.

scholarly journals Evaluating and Improving Small Subunit rRNA PCR Primer Coverage for Bacteria, Archaea, and Eukaryotes Using Metagenomes from Global Ocean Surveys

mSystems ◽  
2021 ◽  
Author(s):  
Jesse McNichol ◽  
Paul M. Berube ◽  
Steven J. Biller ◽  
Jed A. Fuhrman
Keyword(s):  
Microbial Communities ◽  
Low Cost ◽  
Pcr Amplification ◽  
Small Subunit ◽  
Global Ocean ◽  
Marker Genes ◽  
Small Subunit Rrna ◽  
Short Read ◽  
Globally Distributed ◽  
Pcr Primer

PCR amplification and sequencing of marker genes are a low-cost technique for monitoring prokaryotic and eukaryotic microbial communities across space and time but will work optimally only if environmental organisms match PCR primer sequences exactly. In this study, we evaluated how well primers match globally distributed short-read oceanic metagenomes.

scholarly journals The microbiome of the Black Sea water column analyzed by shotgun and genome centric metagenomics

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Pedro J. Cabello-Yeves ◽  
Cristiana Callieri ◽  
Antonio Picazo ◽  
Maliheh Mehrshad ◽  
Jose M. Haro-Moreno ◽  
...  
Keyword(s):  
Black Sea ◽  
Sea Water ◽  
Water Layer ◽  
Water Masses ◽  
Cariaco Basin ◽  
Global Ocean ◽  
The Black Sea ◽  
Marker Genes ◽  
Oxic Zone ◽  
Physicochemical Features

Abstract Background The Black Sea is the largest brackish water body in the world, although it is connected to the Mediterranean Sea and presents an upper water layer similar to some regions of the former, albeit with lower salinity and temperature. Despite its well-known hydrology and physicochemical features, this enormous water mass remains poorly studied at the microbial genomics level. Results We have sampled its different water masses and analyzed the microbiome by shotgun and genome-resolved metagenomics, generating a large number of metagenome-assembled genomes (MAGs) from them. We found various similarities with previously described Black Sea metagenomic datasets, that show remarkable stability in its microbiome. Our datasets are also comparable to other marine anoxic water columns like the Cariaco Basin. The oxic zone resembles to standard marine (e.g. Mediterranean) photic zones, with Cyanobacteria (Synechococcus but a conspicuously absent Prochlorococcus), and photoheterotrophs domination (largely again with marine relatives). The chemocline presents very different characteristics from the oxic surface with many examples of chemolithotrophic metabolism (Thioglobus) and facultatively anaerobic microbes. The euxinic anaerobic zone presents, as expected, features in common with the bottom of meromictic lakes with a massive dominance of sulfate reduction as energy-generating metabolism, a few (but detectable) methanogenesis marker genes, and a large number of “dark matter” streamlined genomes of largely unpredictable ecology. Conclusions The Black Sea oxic zone presents many similarities to the global ocean while the redoxcline and euxinic water masses have similarities to other similar aquatic environments of marine (Cariaco Basin or other Black Sea regions) or freshwater (meromictic monimolimnion strata) origin. The MAG collection represents very well the different types of metabolisms expected in this kind of environment. We are adding critical information about this unique and important ecosystem and its microbiome.

scholarly journals Interpreting ecology and physiology of fossil decapod crustaceans

2003 ◽  
Vol 72 (2-3) ◽  
pp. 111-117 ◽  
Author(s):  
Rodney M. Feldmann
Keyword(s):  
Fossil Record ◽  
Behavioral Responses ◽  
Behavioral Characteristics ◽  
Tissue Preservation ◽  
Aquatic Habitats ◽  
Decapod Crustaceans ◽  
Life Styles ◽  
Morphological Variants ◽  
Diversity Of Life ◽  
Vast Range

Decapods are the most diverse and complex group of crustaceans, adapted for life in all parts of the marine environment, many aquatic habitats, and some terrestrial niches. With this diversity of life styles, a vast range of morphotypes of decapods has evolved, exploiting almost every imaginable variation in morphology of the complex exoskeleton that characterizes them. Many of the morphological variants are a response to exploiting a particular niche in which the organisms live or an adaptation to particular behavioral characteristics. Assessing the significance of morphological variation in the fossil record is challenging because of the taphonomic overprint that results in loss of soft tissue, preservation of partial remains of hard parts, and vastly reduced numbers of preserved individuals as contrasted to the once-living population. The purpose of the present paper is to identify aspects of morphology that may be useful in interpreting the behavioral responses of the organism to its environment, with primary emphasis on morphological features of the exoskeleton that are not expressed on all individuals but that occur at low, and unpredictable, frequencies.

scholarly journals A skull of a very large crane from the late Miocene of Southern Germany, with notes on the phylogenetic interrelationships of extant Gruinae

2020 ◽  
Vol 161 (4) ◽  
pp. 923-933
Author(s):  
Gerald Mayr ◽  
Thomas Lechner ◽  
Madelaine Böhme
Keyword(s):  
Late Miocene ◽  
Fossil Record ◽  
Morphological Characteristics ◽  
Southern Germany ◽  
Siberian Crane ◽  
Large Size ◽  
Early Late

Abstract We describe a partial skull of a very large crane from the early late Miocene (Tortonian) hominid locality Hammerschmiede in southern Germany, which is the oldest fossil record of the Gruinae (true cranes). The fossil exhibits an unusual preservation in that only the dorsal portions of the neurocranium and beak are preserved. Even though it is, therefore, very fragmentary, two morphological characteristics are striking and of paleobiological significance: its large size and the very long beak. The fossil is from a species the size of the largest extant cranes and represents the earliest record of a large-sized crane in Europe. Overall, the specimen resembles the skull of the extant, very long-beaked Siberian Crane, Leucogeranus leucogeranus, but its affinities within Gruinae cannot be determined owing to the incomplete preservation. Judging from its size, the fossil may possibly belong to the very large “Grus” pentelici, which stems from temporally and geographically proximate sites. The long beak of the Hammerschmiede crane conforms to an open freshwater paleohabitat, which prevailed at the locality.

Re-Os PYRITE GEOCHRONOLOGY OF THE YELLOWHEAD-TYPE MINERALIZATION, PEND OREILLE MINE, KOOTENAY ARC, METALINE DISTRICT, WASHINGTON

2020 ◽  
Vol 115 (7) ◽  
pp. 1373-1384
Author(s):  
Suzanne Paradis ◽  
Danny Hnatyshin ◽  
George J. Simandl ◽  
Robert A. Creaser
Keyword(s):  
Fossil Record ◽  
Open Space ◽  
The United States ◽  
Textural Analysis ◽  
Sulfide Deposit ◽  
Sulfide Mineralization ◽  
Space Filling ◽  
Middle Cambrian ◽  
Metal Mine ◽  
Igneous Activity

Abstract Pend Oreille, a carbonate-hosted Zn-Pb sulfide deposit, is the only base metal mine recently in production within the historically prolific Kootenay arc belt. The deposit consists of two spatially and lithologically distinct types of stratabound, carbonate-hosted Zn-Pb mineralization: Josephine and Yellowhead. The Yellowhead-type sulfide mineralization, the focus of this study, consists of en échelon tabular to lensoidal pyrite-sphalerite–rich orebodies hosted by the middle Cambrian to Early Ordovician Metaline Formation. The Yellowhead-type mineralization is characterized by carbonate replacement and open-space filling textures, indicating diagenetic and epigenetic origin. As with most low-temperature deposits not directly associated with igneous activity, the timing of sulfide mineralization has traditionally been difficult to constrain using radiometric methods. In this study, we present a new Re-Os age of 512 ± 17 Ma from the Yellowhead mineralization. Combining this age date with the Cambrian-Ordovician fossil record of the host Metaline Formation and detailed textural analysis of the mineralization, we conclude that the Yellowhead sulfide mineralization is largely diagenetic in origin. Such an origin for the Yellowhead mineralization is similar to that of Irish-type deposits worldwide. For explorationists, the presence of Irish-type deposits in the United States portion of the Kootenay arc opens the possibility of discovering similar mineralization in the Canadian extension of the Kootenay arc.

Columnar shell structures in early linguloid brachiopods – new data from the Middle Cambrian of Sweden

2007 ◽  
Vol 98 (3-4) ◽  
pp. 221-232 ◽  
Author(s):  
Michael Streng ◽  
Lars E. Holmer ◽  
Leonid E. Popov ◽  
Graham E. Budd
Keyword(s):  
New Taxa ◽  
Structure Data ◽  
Shell Structure ◽  
Type Species ◽  
Morphological Characteristics ◽  
Structural Type ◽  
Systematic Position ◽  
Shell Structures ◽  
Southern Sweden ◽  
Middle Cambrian

ABSTRACTThe records of columnar shell structures of linguloid brachiopods (Class Lingulata, Order Lingulida, Superfamily Linguloidea) are reviewed in the light of the discovery of two new taxa from the Middle Cambrian Forsemölla Limestone Bed of southern Sweden. The linguloid taxa, described here as Eoobolus? sp. aff. E. priscus (Poulsen) and Canalilatus? simplex sp. nov., are both characterised by a columnar shell structure, a structural type that is representative for acrotretoid brachiopods and that has previously only rarely been reported from the linguloids. Though the two taxa are superficially similar to known genera, i.e., Eoobolus and Canalilatus, their shell structure challenges such affiliations, as the shell structure of the type species of these genera is previously unknown. Linguloid families whose morphological characteristics agree the most with those of the new taxa, i.e., the Zhanatellidae and the Eoobolidae, and from which columnar shell structures have been reported, i.e., the Lingulellotretidae and the Kyrshabaktellidae, are reviewed briefly. Many taxa assigned to these families completely lack shell structure data and are in need of restudy in order to elucidate their systematic position. Knowledge of the representative type of shell structure of the various suprageneric taxa within the Linguloidea is considered crucial, in order to unravel their currently poorly resolved phylogenetic relationships.

scholarly journals Furongian (Jiangshanian) occurrences of radiodonts in Poland and South China and the fossil record of the Hurdiidae

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11800
Author(s):  
Xuejian Zhu ◽  
Rudy Lerosey-Aubril ◽  
Javier Ortega-Hernández
Keyword(s):  
South China ◽  
Fossil Record ◽  
Marine Ecosystems ◽  
Middle Cambrian ◽  
Early Devonian ◽  
Early Ordovician ◽  
Marine Life ◽  
Oral Cone ◽  
The Family ◽  
Sandstone Formation

The Furongian period represents an important gap in the fossil record of most groups of non-biomineralizing organisms, owing to a scarcity of Konservat-Lagerstätten of that age. The most significant of these deposits, the Jiangshanian strata of the Sandu Formation near Guole Township (Guangxi, South China), have yielded a moderately abundant, but taxonomically diverse soft-bodied fossil assemblage, which provides rare insights into the evolution of marine life at that time. In this contribution, we report the first discovery of a radiodont fossil from the Guole Konservat-Lagerstätte. The specimen is an incomplete frontal appendage of a possibly new representative of the family Hurdiidae. It is tentatively interpreted as composed of seven podomeres, six of which bearing laminiform endites. The best preserved of these endites is especially long, and it bears short auxiliary spines that greatly vary in size. This is the second occurrence of hurdiids and more generally radiodonts in the Furongian, the first being the external mould of an oral cone from Jiangshanian strata of the Wiśniówka Sandstone Formation in Poland. Restudy of this Polish specimen confirms that it belongs to a hurdiid radiodont and best compares to Peytoia. The family Hurdiidae includes the oldest (basal Cambrian Epoch 2) and youngest (Early Ordovician, possibly Early Devonian) representatives of the Radiodonta and as such, has the longest stratigraphical range of the group. Yet, hurdiids only became prominent components of marine ecosystems during the middle Cambrian (Miaolingian), and their fossil record in younger strata remains limited.

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