Systematics and paleobiogeography of Late TriassicGryphaea(Bivalvia) from the North American Cordillera

1992 ◽  
Vol 66 (1) ◽  
pp. 28-39 ◽  
Author(s):  
Christopher A. Mcroberts
Keyword(s):  
North American ◽  
Late Triassic ◽  
South American ◽  
Long Distance ◽  
Low Latitude ◽  
North American Cordillera ◽  
The North ◽  
North American Craton ◽  
Far Eastern ◽  
North And South

Evaluation of previously undescribed collections of Late TriassicGryphaeafrom the North American Cordillera increases the temporal range and geographic distribution of the genus.Gryphaea(Gryphaea)arcuataeformisKiparisova,G.cf.G.(Gryphaea)keilhauiBöhm, and a new species,G.(Gryphaea)nevadensis, occur in lower Carnian to upper Norian strata from Alaska, British Columbia, Oregon, and Nevada. The distribution is mostly primary with respect to the Upper Triassic North American Craton, and requires long-distance larval dispersal along the latitude of far-eastern Panthalassa. Unlike most modern oysters, the distribution of these Triassic gryphaeids may have been restricted to cool and deeper water environments.An early Carnian age ofGryphaea(Gryphaea)arcuataeformisplaces this species as the oldest knownGryphaea. When combined with late Carnian and Norian occurrences from the North and South American Cordillera, these data indicate that a low-latitude origin for the genus cannot be overlooked. Gryphaeids survived the end-Triassic extinction event presumably by living in refugia.

Systematics and Paleoecology of Norian (Late Triassic) Bivalves from a Tropical Island Arc: Wallowa Terrane, Oregon

1987 ◽  
Vol 61 (S22) ◽  
pp. 1-83 ◽  
Author(s):  
Cathryn R. Newton ◽  
Michael T. Whalen ◽  
Joel B. Thompson ◽  
Nienke Prins ◽  
David Delalla
Keyword(s):  
North American ◽  
Island Arc ◽  
Late Triassic ◽  
Small Scale ◽  
Long Distance ◽  
Tropical Island ◽  
North American Cordillera ◽  
The North ◽  
Wallowa Terrane ◽  
Hells Canyon

Early Norian silicified bivalves from Hells Canyon in the Wallowa terrane of northeastern Oregon are part of a rich molluscan biota associated with a tropical island arc. The Hells Canyon locality preserves lenses of silicified shells formed as tempestites in a shallow subtidal carbonate environment. These shell assemblages are parautochthonous and reflect local, rather than long-distance, transport. Silicification at this locality involved small-scale replacement of original calcareous microstructures, or small-scale replacement of neomorphosed shells, without an intervening phase of moldic porosity. This incremental replacement of carbonate by silica contrasts markedly with void-filling silicification textures reported previously from silicified Permian bivalve assemblages.The bivalve paleoecology of this site indicates a suspension feeding biota existing on and within the interstices of coral-spongiomorph thickets, and inhabiting laterally adjacent substrates of peloidal carbonate sand. The bivalve fauna is ecologically congruent with the reef-dwelling molluscs associated with Middle Triassic sponge-coral buildups in the Cassian Formation of the Dolomites (Fuersich and Wendt, 1977). Hells Canyon is a particularly important early Norian locality because of the diversity of substrate types and because the site includes many first occurrences of bivalves in the North American Cordillera. These first occurrences include the first documentation of the important epifaunal families Pectinidae and Terquemiidae in Triassic rocks of the North American Cordillera.The large number of biogeographic and geochronologic range extensions discovered in this single tropical Norian biota indicates that use of literature-based range data for Late Triassic bivalves may be very hazardous. Many bivalve taxa formerly thought to have gone extinct in Karnian time have now been documented from Norian strata in this arc terrane. These range extensions, coupled with the high bivalve species richness of the Hells Canyon site, suggest that the Karnian mass extinction in several literature-based compilations may be an artifact of incomplete sampling. Even for the Norian, present compilations of molluscan extinction may have an unacceptably large artifactual component.Thirty-five bivalve taxa from the Hells Canyon locality are discussed. Of these, seven are new: the mytilid Mysidiella cordillerana n. sp., the limacean Antiquilima vallieri n. sp., the true oyster Liostrea newelli n. sp., the pectinacean Crenamussium concentricum n. gen. and sp., the unioid Cardinioides josephus n. sp., the trigoniacean Erugonia canyonensis n. gen. and sp., and the carditacean Palaeocardita silberlingi n. sp.

The Kinetic Empires of Native American Nomads

2021 ◽  
pp. 1035-1057
Author(s):  
Pekka Hämäläinen
Keyword(s):  
Native American ◽  
South America ◽  
Great Plains ◽  
South American ◽  
Collective Identities ◽  
Long Distance ◽  
The North ◽  
Political Unity ◽  
And Control ◽  
North And South

This chapter re-examines the powerful nomadic-equestrian societies in the North and South American grasslands and makes the case for a distinctive imperial formation, the kinetic empire. Kinetic empires were shape-shifting, action-based regimes that turned mobility into an imperial strategy and revolved around mobile activities: long-distance raiding, seasonal expansions, transnational diplomatic missions, semi-permanent trade fairs, recurring political assemblies, and control over shifting nodes. Their governing systems were light and flexible, and they rose and stayed in power by capitalizing on their superior capacity to access and connect political and economic centers around them. The Comanche and Lakota Indians created the Western Hemisphere’s most prominent examples of kinetic empires in the North American Great Plains. In South America the Araucanians frustrated European colonizing efforts, commanded a large and expanding territory, and pulled other Native groups on their orbit, but lacked the Comanches’ and Lakotas’ strong collective identities and political unity.

Biostratigraphic and biogeographic constraints on the Carboniferous to Jurassic Cache Creek Terrane in central British Columbia

2001 ◽  
Vol 38 (4) ◽  
pp. 551-578 ◽  
Author(s):  
M J Orchard ◽  
F Cordey ◽  
L Rui ◽  
E W Bamber ◽  
B Mamet ◽  
...  
Keyword(s):  
North American ◽  
Early Jurassic ◽  
Late Carboniferous ◽  
Middle Permian ◽  
Late Triassic ◽  
Fine Grained ◽  
North American Continent ◽  
The North ◽  
Carbonate Buildups ◽  
North American Craton

Conodonts, radiolarians, foraminiferids, and corals provide constraints on the geology and tectonics of the Nechako region. They also support the notion that the Cache Creek Terrane is allochthonous with respect to the North American craton. The 177 conodont collections, assigned to 20 faunas, range in age from Bashkirian (Late Carboniferous) to Norian (Late Triassic); 70 radiolarian collections representing 12 zones range from Gzhelian (Late Carboniferous) to Toarcian (Early Jurassic); 335 collections assigned to 11 fusulinacean assemblages (with associated foram-algal associations) range from Bashkirian to Wordian (Middle Permian); and two coral faunas are of Bashkirian and Wordian age. The fossils document a long but sporadic history of sedimentary events within the Cache Creek Complex that included two major carbonate buildups in the Late Carboniferous (Pope limestone) and Middle Permian (Copley limestone), punctuated by intervening Early Permian deepening; basaltic eruptions during the mid Carboniferous and mid Permian; the onset of oceanic chert sedimentation close to the Carboniferous–Permian boundary and its persistence through the Late Triassic (Sowchea succession); latest Permian and Early Triassic mixed clastics and volcanics (Kloch Lake succession); Middle and Late Triassic reworking of carbonates (Whitefish limestone), including cavity fill in older limestones (Necoslie breccia), and fine-grained clastic sedimentation extending into the Early Jurassic (Tezzeron succession). Tethyan, eastern Pacific, and (or) low-latitude biogeographic attributes of the faunas are noted in the Gzhelian (fusulines), Artinskian (conodonts, fusulines), Wordian (fusulines, corals, conodonts), and Ladinian (conodonts, radiolarians). The Cache Creek Terrane lay far to the west of the North American continent during these times.

RAPD analysis of the relationship of North and South American subspecies of Fragaria chiloensis

1998 ◽  
Vol 76 (10) ◽  
pp. 1812-1817 ◽  
Author(s):  
Sue Porebski ◽  
Paul M Catling
Keyword(s):  
North American ◽  
Random Amplified Polymorphic Dna ◽  
Molecular Evidence ◽  
South American ◽  
Cophenetic Correlation ◽  
The North ◽  
Fragaria Chiloensis ◽  
Protection And Utilization ◽  
Relationship Of ◽  
North And South

To improve the intraspecific classification of Fragaria chiloensis (L.) Duchesne, 35 plants including 5 North American ssp. lucida, 15 North American ssp. pacifica, and 15 South American ssp. chiloensis were analysed using random amplified polymorphic DNA (RAPDs). From 100 primers screened, 12 were selected providing 62 scorable polymorphic bands. The phenogram (cophenetic correlation, r = 0.99) based on UPGMA clustering of Jaccard's coefficients revealed a clear division between North American and South American plants, but only partial separation was shown between the two North American subspecies. This is the first comprehensive molecular evidence for major genetic divergence between the North American and South American subspecies of F. chiloensis and suggests greater genetic variation within the Canadian material of the North American ssp. pacifica than within the South American ssp.chiloensis. These findings strongly support protection and utilization of wild Canadian Fragaria germplasm for crop improvement.Key words: strawberry, Fragaria chiloensis, ssp. chiloensis, ssp. pacifica, ssp. lucida, RAPD, variation, germplasm, Canada, United States, Chile.

scholarly journals Ancient mitochondrial DNA reveals convergent evolution of giant short-faced bears (Tremarctinae) in North and South America

2016 ◽  
Vol 12 (4) ◽  
pp. 20160062 ◽  
Author(s):  
Kieren J. Mitchell ◽  
Sarah C. Bray ◽  
Pere Bover ◽  
Leopoldo Soibelzon ◽  
Blaine W. Schubert ◽  
...  
Keyword(s):  
South America ◽  
North American ◽  
Convergent Evolution ◽  
Phylogenetic Analyses ◽  
Early Pleistocene ◽  
South American ◽  
The North ◽  
Molecular Phylogenetic ◽  
North And South America ◽  
North And South

The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear ( Tremarctos ornatus ), a largely herbivorous bear that is today only found in South America. The relationships among the spectacled bears ( Tremarctos ), South American short-faced bears ( Arctotherium ) and North American short-faced bears ( Arctodus ) remain uncertain. In this study, we sequenced a mitochondrial genome from an Arctotherium femur preserved in a Chilean cave. Our molecular phylogenetic analyses revealed that the South American short-faced bears were more closely related to the extant South American spectacled bear than to the North American short-faced bears. This result suggests striking convergent evolution of giant forms in the two groups of short-faced bears ( Arctodus and Arctotherium ), potentially as an adaptation to dominate competition for megafaunal carcasses.

Differences in bleaching responses from fungal- versus bacterial-derived enzymes

TAPPI Journal ◽  
2012 ◽  
Vol 11 (3) ◽  
pp. 21-27 ◽  
Author(s):  
PETER W. HART
Keyword(s):  
North American ◽  
Cost Savings ◽  
Operating Conditions ◽  
South American ◽  
Oxygen Delignification ◽  
The North ◽  
Eucalyptus Pulp ◽  
The One ◽  
Enzyme Bleaching ◽  
North And South

Several mills in North America have been successful in using xylanase enzymes expressed from Trichoderma reesei (a fungus) as part of their bleaching sequence for many years. These mills process hardwood and softwood species, with and without oxygen delignification. These mills also use three-, four-, and five-stage bleaching sequences. North American mills tend to report increased pulp brightness ceilings and decreased bleaching costs as benefits associated with the application of enzymes in the bleaching process. Laboratory testing suggests that eucalyptus pulp is highly susceptible to fungal- and bacterial-derived enzyme bleaching and should result in significant cost savings in South American mills. At least four different mills in South America have attempted to perform enzyme bleaching trials using bacterial-derived enzymes. Each of these mill trials resulted in significantly increased operating costs and/or unsustainable operating conditions. More recently, one of these South American mills performed a short trial using a commercially available, fungal-derived enzyme. This trial was technically successful. This report attempts to determine why the South American mill experiences with bacterial-derived enzymes have been poor, while North American mills and the one South American mill trial have had good results with fungal-derived enzymes. Operating conditions and trial goals for the North and South American mills also were examined.

CYTOTAXONOMIC STUDIES ON NEW WORLD SPECIES OF ANEMONE (SECTION ERIOCEPHALUS) WITH TUBEROUS ROOTSTOCKS

1966 ◽  
Vol 44 (7) ◽  
pp. 899-928 ◽  
Author(s):  
Cecily Joseph ◽  
Margaret Heimburger
Keyword(s):  
North American ◽  
New World ◽  
Diploid Species ◽  
Pollen Grain ◽  
South American ◽  
New Taxon ◽  
South American Species ◽  
The North ◽  
Additional Support ◽  
North And South

The American species of Anemone L. (section Eriocephalus Hook. f. & Thoms.) with tuberous rootstocks were studied by biosystematic methods. Anemone caroliniana Walt., A. heterophylla Nutt. ex Torr. & Gray, A. tuberosa Rydb., and A. edwardsiana Tharp (tentatively) are recognized from North America and A. decapetala Ard., A. triternata Vahl, and A. cicutifolia Johnst. from South America. Karyotypes of the diploid species (2n = 16), A. heterophylla, A. tuberosa, A. decapetala, and A. triternata are described. They resemble the karyotype of A. caroliniana published earlier. Anemone edwardsiana and A. cicutifolia are also presumed diploid from stomatal and pollen grain studies. A new taxon (2n = 32), of undecided status, was obtained from Chile. North American plants included by authors in A. decapetala are here referred to A. heterophylla. The North and South American species appear to form two separate groups, the species of each continent being more closely related among themselves than to those of the other continent. Fewer stomata, larger chromosome size, and higher DNA content are characteristic of the North American species. Additional support for the separation of the two groups derives from limited meiotic studies which indicate a larger number of inversion differences in inter- than in intra-continental hybrids.

Diversification of the North American Doellingeria-Eucephalus Clade (Astereae: Asteraceae) Inferred from Molecular and Morphological Evidence

2019 ◽  
Vol 44 (4) ◽  
pp. 930-942
Author(s):  
Geraldine A. Allen ◽  
Luc Brouillet ◽  
John C. Semple ◽  
Heidi J. Guest ◽  
Robert Underhill
Keyword(s):  
North American ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Sister Group ◽  
Morphological Evidence ◽  
South American ◽  
New Combinations ◽  
The North ◽  
Hybridization Event ◽  
Ancient Hybridization

Abstract—Doellingeria and Eucephalus form the earliest-diverging clade of the North American Astereae lineage. Phylogenetic analyses of both nuclear and plastid sequence data show that the Doellingeria-Eucephalus clade consists of two main subclades that differ from current circumscriptions of the two genera. Doellingeria is the sister group to E. elegans, and the Doellingeria + E. elegans subclade in turn is sister to the subclade containing all remaining species of Eucephalus. In the plastid phylogeny, the two subclades are deeply divergent, a pattern that is consistent with an ancient hybridization event involving ancestral species of the Doellingeria-Eucephalus clade and an ancestral taxon of a related North American or South American group. Divergence of the two Doellingeria-Eucephalus subclades may have occurred in association with northward migration from South American ancestors. We combine these two genera under the older of the two names, Doellingeria, and propose 12 new combinations (10 species and two varieties) for all species of Eucephalus.

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