Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina

Autores
Bordonaro, Osvaldo Luis; Pratt, Brian R.; Robledo, Virginia
Año de publicación
2012
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The ptychoparioid trilobite Blainia gregaria Walcott, 1916 is described for the first time from the late middle Cambrian (Series 3) of the Argentine Precordillera. It occurs commonly in the upper part of La Laja Formation, a carbonate platform succession that crops out in the Precordillera Oriental of San Juan where it reaches a thickness of some 600 m. Sections were sampled on cerro Tres Marías in Sierra de Marquesado and in quebrada de Zonda at the northern termination of Sierra Chica de Zonda. More than 1200 specimens were recovered from 22 stratigraphic levels over a thickness of 155 m, located in the uppermost 15 m of the Soldano Member, the approximately 100 m thick Rivadavia Member, and in the lower 40 m of the Juan Pobre Member. Our biometric study dealt with 205 cranidia and 365 pygidia from cerro Tres Marías. Measured dimensions of a subset of this collection provide bivariate datasets that in some characters show broad scatter plots and relatively low linear correlation coefficients, indicative of rather wide intraspecific morphological variation. Six morphotypes (three cranidial and three pygidial), recognized mainly on the basis of shape, occur together in the same collections. This evidence for an unusually high degree of variability leads to a proposed synonymy of some 30 previously named species in North America belonging to two genera,Blainia Walcott, 1916 and Glyphaspis Poulsen, 1927, the latter considered a junior synonym. The biogeographic distribution of B. gregaria, as redefined here, shows that it was an endemic Laurentian species that inhabited the inner parts of the carbonate platform that rimmed the craton and mantled portions of its interior. Its presence in western Argentina is further evidence for the very close faunal relationship between the Precordilleran terrane, known as Cuyania, and Laurentia during the Cambrian.
Fil: Bordonaro, Osvaldo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina
Fil: Pratt, Brian R.. University of Saskatchewan. Department of Geological Sciences; Canadá
Fil: Robledo, Virginia. Universidad del Aconcagua. Instituto Superior del Profesorado San Pedro Nolasco; Argentina
Materia
Trilobites
Middle Cambrian
Intraspecific Variation
Precordillera Argentina
Ptychopariida
Morphometrics
Precordillera
Argentina
Palaeobiogeography
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/4826

id CONICETDig_f876d28f4ed47845a16e12eec48d051c
oai_identifier_str oai:ri.conicet.gov.ar:11336/4826
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western ArgentinaBordonaro, Osvaldo LuisPratt, Brian R.Robledo, VirginiaTrilobitesMiddle CambrianIntraspecific VariationPrecordillera ArgentinaPtychopariidaMorphometricsPrecordilleraArgentinaPalaeobiogeographyhttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1The ptychoparioid trilobite Blainia gregaria Walcott, 1916 is described for the first time from the late middle Cambrian (Series 3) of the Argentine Precordillera. It occurs commonly in the upper part of La Laja Formation, a carbonate platform succession that crops out in the Precordillera Oriental of San Juan where it reaches a thickness of some 600 m. Sections were sampled on cerro Tres Marías in Sierra de Marquesado and in quebrada de Zonda at the northern termination of Sierra Chica de Zonda. More than 1200 specimens were recovered from 22 stratigraphic levels over a thickness of 155 m, located in the uppermost 15 m of the Soldano Member, the approximately 100 m thick Rivadavia Member, and in the lower 40 m of the Juan Pobre Member. Our biometric study dealt with 205 cranidia and 365 pygidia from cerro Tres Marías. Measured dimensions of a subset of this collection provide bivariate datasets that in some characters show broad scatter plots and relatively low linear correlation coefficients, indicative of rather wide intraspecific morphological variation. Six morphotypes (three cranidial and three pygidial), recognized mainly on the basis of shape, occur together in the same collections. This evidence for an unusually high degree of variability leads to a proposed synonymy of some 30 previously named species in North America belonging to two genera,Blainia Walcott, 1916 and Glyphaspis Poulsen, 1927, the latter considered a junior synonym. The biogeographic distribution of B. gregaria, as redefined here, shows that it was an endemic Laurentian species that inhabited the inner parts of the carbonate platform that rimmed the craton and mantled portions of its interior. Its presence in western Argentina is further evidence for the very close faunal relationship between the Precordilleran terrane, known as Cuyania, and Laurentia during the Cambrian.Fil: Bordonaro, Osvaldo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Pratt, Brian R.. University of Saskatchewan. Department of Geological Sciences; CanadáFil: Robledo, Virginia. Universidad del Aconcagua. Instituto Superior del Profesorado San Pedro Nolasco; ArgentinaWiley2012-01-13info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/4826Bordonaro, Osvaldo Luis; Pratt, Brian R.; Robledo, Virginia; Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina; Wiley; Geological Journal; 48; 2-3; 13-1-2012; 126-1410072-1050enginfo:eu-repo/semantics/altIdentifier/doi/info:eu-repo/semantics/altIdentifier/url/http://onlinelibrary.wiley.com/doi/10.1002/gj.1344/abstractinfo:eu-repo/semantics/altIdentifier/doi/10.1002/gj.1344info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:47:31Zoai:ri.conicet.gov.ar:11336/4826instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-03 09:47:31.698CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina
title Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina
spellingShingle Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina
Bordonaro, Osvaldo Luis
Trilobites
Middle Cambrian
Intraspecific Variation
Precordillera Argentina
Ptychopariida
Morphometrics
Precordillera
Argentina
Palaeobiogeography
title_short Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina
title_full Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina
title_fullStr Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina
title_full_unstemmed Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina
title_sort Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina
dc.creator.none.fl_str_mv Bordonaro, Osvaldo Luis
Pratt, Brian R.
Robledo, Virginia
author Bordonaro, Osvaldo Luis
author_facet Bordonaro, Osvaldo Luis
Pratt, Brian R.
Robledo, Virginia
author_role author
author2 Pratt, Brian R.
Robledo, Virginia
author2_role author
author
dc.subject.none.fl_str_mv Trilobites
Middle Cambrian
Intraspecific Variation
Precordillera Argentina
Ptychopariida
Morphometrics
Precordillera
Argentina
Palaeobiogeography
topic Trilobites
Middle Cambrian
Intraspecific Variation
Precordillera Argentina
Ptychopariida
Morphometrics
Precordillera
Argentina
Palaeobiogeography
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The ptychoparioid trilobite Blainia gregaria Walcott, 1916 is described for the first time from the late middle Cambrian (Series 3) of the Argentine Precordillera. It occurs commonly in the upper part of La Laja Formation, a carbonate platform succession that crops out in the Precordillera Oriental of San Juan where it reaches a thickness of some 600 m. Sections were sampled on cerro Tres Marías in Sierra de Marquesado and in quebrada de Zonda at the northern termination of Sierra Chica de Zonda. More than 1200 specimens were recovered from 22 stratigraphic levels over a thickness of 155 m, located in the uppermost 15 m of the Soldano Member, the approximately 100 m thick Rivadavia Member, and in the lower 40 m of the Juan Pobre Member. Our biometric study dealt with 205 cranidia and 365 pygidia from cerro Tres Marías. Measured dimensions of a subset of this collection provide bivariate datasets that in some characters show broad scatter plots and relatively low linear correlation coefficients, indicative of rather wide intraspecific morphological variation. Six morphotypes (three cranidial and three pygidial), recognized mainly on the basis of shape, occur together in the same collections. This evidence for an unusually high degree of variability leads to a proposed synonymy of some 30 previously named species in North America belonging to two genera,Blainia Walcott, 1916 and Glyphaspis Poulsen, 1927, the latter considered a junior synonym. The biogeographic distribution of B. gregaria, as redefined here, shows that it was an endemic Laurentian species that inhabited the inner parts of the carbonate platform that rimmed the craton and mantled portions of its interior. Its presence in western Argentina is further evidence for the very close faunal relationship between the Precordilleran terrane, known as Cuyania, and Laurentia during the Cambrian.
Fil: Bordonaro, Osvaldo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina
Fil: Pratt, Brian R.. University of Saskatchewan. Department of Geological Sciences; Canadá
Fil: Robledo, Virginia. Universidad del Aconcagua. Instituto Superior del Profesorado San Pedro Nolasco; Argentina
description The ptychoparioid trilobite Blainia gregaria Walcott, 1916 is described for the first time from the late middle Cambrian (Series 3) of the Argentine Precordillera. It occurs commonly in the upper part of La Laja Formation, a carbonate platform succession that crops out in the Precordillera Oriental of San Juan where it reaches a thickness of some 600 m. Sections were sampled on cerro Tres Marías in Sierra de Marquesado and in quebrada de Zonda at the northern termination of Sierra Chica de Zonda. More than 1200 specimens were recovered from 22 stratigraphic levels over a thickness of 155 m, located in the uppermost 15 m of the Soldano Member, the approximately 100 m thick Rivadavia Member, and in the lower 40 m of the Juan Pobre Member. Our biometric study dealt with 205 cranidia and 365 pygidia from cerro Tres Marías. Measured dimensions of a subset of this collection provide bivariate datasets that in some characters show broad scatter plots and relatively low linear correlation coefficients, indicative of rather wide intraspecific morphological variation. Six morphotypes (three cranidial and three pygidial), recognized mainly on the basis of shape, occur together in the same collections. This evidence for an unusually high degree of variability leads to a proposed synonymy of some 30 previously named species in North America belonging to two genera,Blainia Walcott, 1916 and Glyphaspis Poulsen, 1927, the latter considered a junior synonym. The biogeographic distribution of B. gregaria, as redefined here, shows that it was an endemic Laurentian species that inhabited the inner parts of the carbonate platform that rimmed the craton and mantled portions of its interior. Its presence in western Argentina is further evidence for the very close faunal relationship between the Precordilleran terrane, known as Cuyania, and Laurentia during the Cambrian.
publishDate 2012
dc.date.none.fl_str_mv 2012-01-13
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/4826
Bordonaro, Osvaldo Luis; Pratt, Brian R.; Robledo, Virginia; Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina; Wiley; Geological Journal; 48; 2-3; 13-1-2012; 126-141
0072-1050
url http://hdl.handle.net/11336/4826
identifier_str_mv Bordonaro, Osvaldo Luis; Pratt, Brian R.; Robledo, Virginia; Systematic, morphometric and palaeobiogeographic study of Blainia gregaria Walcott, 1916 (Trilobite, Ptychopariida): Middle Cambrian of the Precordillera of western Argentina; Wiley; Geological Journal; 48; 2-3; 13-1-2012; 126-141
0072-1050
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/
info:eu-repo/semantics/altIdentifier/url/http://onlinelibrary.wiley.com/doi/10.1002/gj.1344/abstract
info:eu-repo/semantics/altIdentifier/doi/10.1002/gj.1344
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Wiley
publisher.none.fl_str_mv Wiley
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
_version_ 1842268864708083712
score 13.13397