Matilde Sylvia BERESI | National Scientific and Technical Research Council (original) (raw)

Papers by Matilde Sylvia BERESI

Episodes, 2010

stratigraphic control and detailed analysis of different facies settings. The work on the rapid e... more stratigraphic control and detailed analysis of different facies settings. The work on the rapid evolution of early ecosystems on land and their interaction with sedimentary processes, climate, and palaeogeography, both on land and in marine settings, was scheduled for the duration of the project (2004-2009). For that reason studies included individual palaeoecosystems and their components as well as their palaeo-biogeographic distribution which should provide a better understanding of the Devonian system with respect to the evolution of palaeoecosystems and to palaeogeographical and palaeoclimatical changes. The project was developed in close collaboration with the Sub-commission on Devonian Stratigraphy (SDS) and many workshops were organized worldwide (Fig. 1), some of them as joint IGCP 499/ SDS meetings.

Acta geológica lilloana, 1981

Geological Society, London, Special Publications, Feb 8, 2023

In Mexico, Ordovician sedimentary rocks are exposed in the states of Baja California, Sonora, Chi... more In Mexico, Ordovician sedimentary rocks are exposed in the states of Baja California, Sonora, Chihuahua and Oaxaca, comprising approximately 30 stratigraphic successions ranging from Lower to Upper Ordovician. The ages of the sequences have been established primarily by utilizing conodonts and graptolites, which have also allowed us to differentiate between platform and oceanic basin environments. The State of Sonora has the most complete Ordovician stratigraphic sequences, ranging from Tremadocian to Hirnantian. The deposits in Baja California are Floian in age, while the sequences of Chihuahua range from Sandbian to Katian, and the deposits in Oaxaca are Tremadocian. The Ordovician deposits of northern Mexico (Baja California, Sonora, and Chihuahua) present a palaeogeographic relationship to the North American craton, mainly owing to faunal interspecific affinities, while the southern deposits (Oaxaca) are controversial owing to the high degree of endemism of the faunas; however, they show affinity with Gondwana, Baltica and Avalonia, with a possible insular origin. The biotic assemblages of the Ordovician of Mexico include a variety of taxa, including algae, poriferans, corals, bryozoans, brachiopods, molluscs, trilobites, echinoderms, graptolites and conodonts as predominant elements. Despite many years of field studies in Mexican Ordovician localities, biostratigraphic correlations are as yet insufficient and incomplete or are based on limited interpretations. Thus, the Ordovician biostratigraphic data from Mexico compiled in the present paper have great potential and significant value. The advancement in the knowledge of the Ordovician biostratigraphy of Mexico will contribute to a major understanding of the relationships with the Ordovician System to a continental scale. Future advances will come mainly through increasing the amount and quality of data as well as improving biocorrelations among the Ordovician sequences of Mexico.

Revista española de paleontología, Dec 1, 2000

Journal of Paleontology, Mar 1, 1994

Anthaspidellid sponges are reported from the La Laja Formation in the Chica de Zonda Range in the... more Anthaspidellid sponges are reported from the La Laja Formation in the Chica de Zonda Range in the Precordillera Oriental, Argentina. These are generically unidentifiable fragments of trabs and more or less well-defined dendroclone spicules. They occur as skeletal elements in small transported fragments and are the only Cambrian occurrence of anthaspidellids known thus far from South America.Walcott (1920) proposed to include an array of dissociated spicules, including triradiate prodiaenes, hexactines, and probable monactine spicules, in the genus Kiwetinokia. Assemblages tentatively identified as Kiwetinokia utahensis? Walcott, 1920, are reported from the Estancia San Martin Formation, of latest Early Cambrian and early Middle Cambrian age from San Isidro Gulch near Mendoza. Similar spicule assemblages occur in the La Laja Formation from the Chica de Zonda Range, in the Precordillera Oriental near San Juan, and in the Los Sombreros Formation in the Tontal Range of the Precordillera Occidental.Sclerites of the sponge-like Chancelloria eros Walcott, 1920, are described from the upper Lower to lower Middle Cambrian La Laja Formation. Chancelloria sclerites are also reported here from rocks of the Middle Cambrian Glossopleura Zone in the San Isidro Formation in Empozada Gulch in the San Isidro area of the Precordillera Austral, west of Mendoza, in Mendoza Province. Sponges and chancelloriids from the Cambrian of Argentina are known basically from dissociated skeletal elements.

LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas), 2017

En esta contribución se da a conocer una nueva localidad fosilífera en la Cantera Los Guanacos de... more En esta contribución se da a conocer una nueva localidad fosilífera en la Cantera Los Guanacos del extremo norte de la sierra de Las Higueras, a 10.5 km de la localidad de Salagasta, Precordillera de Mendoza, oeste de Argentina. Se trata de un nivel carbonático lenticular fosilífero intercalado entre la unidad mixta pelítica/ carbonática (transfacies) correlacionable con la base de la Formación Los Azules. Éste se caracteriza por un límite erosional de espesor milimétrico y por una distribución mecánica de bioclastos e intraclastos, por encima del mudstone basal oscuro. La capa bioclástica se interpreta como el depósito de un evento tempestítico acaecido en la plataforma carbonática. Se determinan las microfacies carbonáticas y las asociaciones de macro y microfauna. Se registran y describen los trilobites Mendolaspis salagastensis y especies indeterminadas de Agnostidae, Illaenidae, Leiostegiidae, Encrinuridae, Telephinidae y Trinucleidae. Se reconocieron braquiópodos indeterminados de la familia Obolidae. Los graptolitos son comparables con Levisograptus cf. austrodentatus y en base a la fauna de conodontos se reconoce la Zona de Yangtzeplacognathus crassus de edad darriwiliense temprana (Ordovícico Medio). Se discuten las implicaciones bioestratigráficas de estos registros, que permiten la correlación de estos niveles de la Precordillera de Mendoza con otras regiones de la Precordillera de San Juan, del Noroeste argentino y del mundo. Se brindan además algunas consideraciones paleoambientales surgidas del análisis de estos registros faunísticos y de las microfacies carbonáticas.

Revista española de paleontología, 1997

Journal of South American Earth Sciences, Jul 1, 2003

This paper describes an Upper Jurassic association of siliceous sponges from the Neuquén basin, s... more This paper describes an Upper Jurassic association of siliceous sponges from the Neuquén basin, southern Mendoza province, at Río Potimalal. Wackestones crop out in this stratigraphic section, and massive sponge-bearing micritic limestones of the La Manga formation (Plicatilis zone) have been deposited in outer shelf to slope settings. Sponges are regularly preserved as whole bodies. Their skeletons are mostly calcified, but the skeletal siliceous structure is sometime preserved. The siliceous sponges belong to the Order Hexactinosa (Class Hexactinellida, Subclass Hexasterophora) (Laocoetis sp., L. parallela, L. procumbens, Cribrospongia sp., C. clathrata, C. cucullata, Ordinatus sp., Linonema calyx) and Lyssakinosa (Poligonatyum sphaeroides). The majority of the sponge specimens correspond to the Families Cribrospongiidae (genus Cribrospongia) and Laocoetidae (genus Laocoetis). The Upper Jurassic carbonates are interpreted as deposits of a highstand systems tract, similar to other Oxfordian sequences found around the world.

Geologica Acta, Jan 11, 2003

Spicules of sponges and sclerites of chancelloriids have been collected from in situ Cambrian sec... more Spicules of sponges and sclerites of chancelloriids have been collected from in situ Cambrian sections of the La Laja Formation (San Juan Precordillera). They have also been collected from carbonate olistoliths, which were emplaced from the Cambrian units in the Early Ordovician Los Sombreros Formation (San Juan Precordillera) and Empozada Formation (Mendoza Precordillera). The Cambrian La Laja Formation sequences were deposited in a shallow carbonate platform in the eastern part of the Precordillera. The Cambrian carbonate rocks, which make up the olistoliths in the Los Sombreros and Empozada Formations, record deposition in the slope environments which developed in the western Precordillera. Cambrian Porifera and sponge-like chancelloriid assemblages are known mainly from fragments of skeletal nets, dissociated spicules and sclerites, which enable us to define two assemblages. The first assemblage of spicules was defined from the upper Lower to Middle Cambrian sequences of the La Laja Formation. This assemblage consists of a variety of stauractines and sclerites of Chancelloria WALCOTT. The family Protospongiidae is represented by triradiate prodianes, pentactines and hexactines, all belonging to Kiwetinokia WALCOTT. The second assemblage, which consists of isolated hexactines, pentactines, monaxons and skeletal nets, was defined in the Cambrian derived olistholiths of the Los Sombreros and Empozada Formations. Early hexactinellid Protospongiidae with body preservation (Diagoniella ? and Kiwetinokia) also occur. Demosponges have a very limited record in the Cambrian of the Precordillera. Anthaspidellid sponges had been reported from the La Laja Formation and now from the San Martín olistolith (Empozada Formation). The occurrences of these two assemblages of spicules and sclerites in both the Cambrian platform and slope facies of the Precordillera contribute additional data for a better understanding of the relationships between the eastern and the western facies assemblages, which developed in the Precordillera during the Cambrian. Therefore, they are useful for paleoenvironmental and paleogeographical interpretations of the Cambrian depositional framework.

Stratigraphy and Geological Correlation, 2018

The Argentine Precordillera, which was part of Gondwana in the Ordovician, is characterized by co... more The Argentine Precordillera, which was part of Gondwana in the Ordovician, is characterized by complex geological evolution, which is reflected in a series of bioevents evident from paleontological data (trilobites, conodonts, brachiopods, graptolites, etc.). An important role also belonged to calcareous algoflora as a major constituent of reefs, which is the main focus of the paper. Some calcareous algae are revised.

Spanish journal of palaeontology, Mar 1, 2022

A moderately diverse fauna of hexactinellid sponges is described f r om one Late Cambrian olistol... more A moderately diverse fauna of hexactinellid sponges is described f r om one Late Cambrian olistolith of the Los Sombreros Formation f r om Tres Saltos Gulch in the Tontal Range,Western Precordillera, San Juan Province, Argentina. Protospongia sp., Diagonieffa? sp., Kiwetinokia, anchoring spicules, prodiaenes, diagonally arranged spicules and root tuft are pr esent. The pr eservation degree of the spicules and the patterns allow us to presume that after their death, they were transported not very far f r om the original sponges oases. The Cambrian oolitic grainstone limestones with spicules conform an olistolith which was transported and re sedimented during the Ordovician by gravity nows within a pelitic matrix of the terrigenous-carbonate talus of the Los Sombreros Formation.

Neues Jahrbuch für Geologie und Paläontologie, Jun 1, 2013

A Middle Cambrian faunule from different sections of the San Isidro region, Precordillera of Mend... more A Middle Cambrian faunule from different sections of the San Isidro region, Precordillera of Mendoza Province, western Argentina, include previously unrecorded and new material. Specimens in the collections are simple reticulosan hexactinellids determined as Diagoniella cf. cyathiformis, Diagoniella sp., (?) Diagoniella sp., indeterminate protospongioid spicule assemblages and several root tuft types. In addition a possible scleritome of Chancelloria cruceana Rusconi, 1954 is re-described and illustrated, and sclerites assigned to Archiasterella are here described for the first time.

Journal of Paleontology

The Lower–Middle Ordovician (Ibexian, Whiterockian) sedimentary rocks exposed at Rancho Las Noria... more The Lower–Middle Ordovician (Ibexian, Whiterockian) sedimentary rocks exposed at Rancho Las Norias includes the informally named Las Norias formation, which consists of an intercalation of carbonate and clastic sediments with abundant marine fauna. These deposits occur as the most austral sedimentary rocks of Ordovician age for Laurentia, providing a critical link to understand the distribution of Ordovician marine faunas of North America. An investigation of the gastropod fauna from the upper portion of the Las Norias formation, Sonora, Mexico, is undertaken for the first time. The gastropod assemblage includes Maclurites acuminatus, ?Monitorella sp., Lecanospira sp., Malayaspira aff. M. rugosa, Lophospira perangulata, and Hormotoma? sp. This assemblage indicates a paleogeographic relationship with Laurentia, including the USA (Nevada), Canada (British Columbia, Newfoundland), Greenland, and the Argentine Precordillera.

Acta geológica lilloana, 1981

Spanish Journal of Palaeontology, 2022

A moderately diverse fauna of hexactinellid sponges is described f r om one Late Cambrian olistol... more A moderately diverse fauna of hexactinellid sponges is described f r om one Late Cambrian olistolith of the Los Sombreros Formation f r om Tres Saltos Gulch in the Tontal Range,Western Precordillera, San Juan Province, Argentina. Protospongia sp., Diagonieffa? sp., Kiwetinokia, anchoring spicules, prodiaenes, diagonally arranged spicules and root tuft are pr esent. The pr eservation degree of the spicules and the patterns allow us to presume that after their death, they were transported not very far f r om the original sponges oases. The Cambrian oolitic grainstone limestones with spicules conform an olistolith which was transported and re sedimented during the Ordovician by gravity nows within a pelitic matrix of the terrigenous-carbonate talus of the Los Sombreros Formation.

Neues Jahrbuch für Geologie und Paläontologie - Monatshefte, 2006

... and Pseudokainella sp.), small linguliform brachio-pods and the sponge material described her... more ... and Pseudokainella sp.), small linguliform brachio-pods and the sponge material described herein (Ricci & Villanueva 1969; Tortello et al ... from the Orcomato Formation is housed at the Paleontological Collection of the Facultad de Ciencias Naturales and Instituto Miguel Lillo as ...

Journal of Paleontology, 1994

Anthaspidellid sponges are reported from the La Laja Formation in the Chica de Zonda Range in the... more Anthaspidellid sponges are reported from the La Laja Formation in the Chica de Zonda Range in the Precordillera Oriental, Argentina. These are generically unidentifiable fragments of trabs and more or less well-defined dendroclone spicules. They occur as skeletal elements in small transported fragments and are the only Cambrian occurrence of anthaspidellids known thus far from South America.Walcott (1920) proposed to include an array of dissociated spicules, including triradiate prodiaenes, hexactines, and probable monactine spicules, in the genus Kiwetinokia. Assemblages tentatively identified as Kiwetinokia utahensis? Walcott, 1920, are reported from the Estancia San Martin Formation, of latest Early Cambrian and early Middle Cambrian age from San Isidro Gulch near Mendoza. Similar spicule assemblages occur in the La Laja Formation from the Chica de Zonda Range, in the Precordillera Oriental near San Juan, and in the Los Sombreros Formation in the Tontal Range of the Precordillera...

Episodes, 2010

stratigraphic control and detailed analysis of different facies settings. The work on the rapid e... more stratigraphic control and detailed analysis of different facies settings. The work on the rapid evolution of early ecosystems on land and their interaction with sedimentary processes, climate, and palaeogeography, both on land and in marine settings, was scheduled for the duration of the project (2004-2009). For that reason studies included individual palaeoecosystems and their components as well as their palaeo-biogeographic distribution which should provide a better understanding of the Devonian system with respect to the evolution of palaeoecosystems and to palaeogeographical and palaeoclimatical changes. The project was developed in close collaboration with the Sub-commission on Devonian Stratigraphy (SDS) and many workshops were organized worldwide (Fig. 1), some of them as joint IGCP 499/ SDS meetings.

Acta geológica lilloana, 1981

Geological Society, London, Special Publications, Feb 8, 2023

In Mexico, Ordovician sedimentary rocks are exposed in the states of Baja California, Sonora, Chi... more In Mexico, Ordovician sedimentary rocks are exposed in the states of Baja California, Sonora, Chihuahua and Oaxaca, comprising approximately 30 stratigraphic successions ranging from Lower to Upper Ordovician. The ages of the sequences have been established primarily by utilizing conodonts and graptolites, which have also allowed us to differentiate between platform and oceanic basin environments. The State of Sonora has the most complete Ordovician stratigraphic sequences, ranging from Tremadocian to Hirnantian. The deposits in Baja California are Floian in age, while the sequences of Chihuahua range from Sandbian to Katian, and the deposits in Oaxaca are Tremadocian. The Ordovician deposits of northern Mexico (Baja California, Sonora, and Chihuahua) present a palaeogeographic relationship to the North American craton, mainly owing to faunal interspecific affinities, while the southern deposits (Oaxaca) are controversial owing to the high degree of endemism of the faunas; however, they show affinity with Gondwana, Baltica and Avalonia, with a possible insular origin. The biotic assemblages of the Ordovician of Mexico include a variety of taxa, including algae, poriferans, corals, bryozoans, brachiopods, molluscs, trilobites, echinoderms, graptolites and conodonts as predominant elements. Despite many years of field studies in Mexican Ordovician localities, biostratigraphic correlations are as yet insufficient and incomplete or are based on limited interpretations. Thus, the Ordovician biostratigraphic data from Mexico compiled in the present paper have great potential and significant value. The advancement in the knowledge of the Ordovician biostratigraphy of Mexico will contribute to a major understanding of the relationships with the Ordovician System to a continental scale. Future advances will come mainly through increasing the amount and quality of data as well as improving biocorrelations among the Ordovician sequences of Mexico.

Revista española de paleontología, Dec 1, 2000

Journal of Paleontology, Mar 1, 1994

Anthaspidellid sponges are reported from the La Laja Formation in the Chica de Zonda Range in the... more Anthaspidellid sponges are reported from the La Laja Formation in the Chica de Zonda Range in the Precordillera Oriental, Argentina. These are generically unidentifiable fragments of trabs and more or less well-defined dendroclone spicules. They occur as skeletal elements in small transported fragments and are the only Cambrian occurrence of anthaspidellids known thus far from South America.Walcott (1920) proposed to include an array of dissociated spicules, including triradiate prodiaenes, hexactines, and probable monactine spicules, in the genus Kiwetinokia. Assemblages tentatively identified as Kiwetinokia utahensis? Walcott, 1920, are reported from the Estancia San Martin Formation, of latest Early Cambrian and early Middle Cambrian age from San Isidro Gulch near Mendoza. Similar spicule assemblages occur in the La Laja Formation from the Chica de Zonda Range, in the Precordillera Oriental near San Juan, and in the Los Sombreros Formation in the Tontal Range of the Precordillera Occidental.Sclerites of the sponge-like Chancelloria eros Walcott, 1920, are described from the upper Lower to lower Middle Cambrian La Laja Formation. Chancelloria sclerites are also reported here from rocks of the Middle Cambrian Glossopleura Zone in the San Isidro Formation in Empozada Gulch in the San Isidro area of the Precordillera Austral, west of Mendoza, in Mendoza Province. Sponges and chancelloriids from the Cambrian of Argentina are known basically from dissociated skeletal elements.

LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas), 2017

En esta contribución se da a conocer una nueva localidad fosilífera en la Cantera Los Guanacos de... more En esta contribución se da a conocer una nueva localidad fosilífera en la Cantera Los Guanacos del extremo norte de la sierra de Las Higueras, a 10.5 km de la localidad de Salagasta, Precordillera de Mendoza, oeste de Argentina. Se trata de un nivel carbonático lenticular fosilífero intercalado entre la unidad mixta pelítica/ carbonática (transfacies) correlacionable con la base de la Formación Los Azules. Éste se caracteriza por un límite erosional de espesor milimétrico y por una distribución mecánica de bioclastos e intraclastos, por encima del mudstone basal oscuro. La capa bioclástica se interpreta como el depósito de un evento tempestítico acaecido en la plataforma carbonática. Se determinan las microfacies carbonáticas y las asociaciones de macro y microfauna. Se registran y describen los trilobites Mendolaspis salagastensis y especies indeterminadas de Agnostidae, Illaenidae, Leiostegiidae, Encrinuridae, Telephinidae y Trinucleidae. Se reconocieron braquiópodos indeterminados de la familia Obolidae. Los graptolitos son comparables con Levisograptus cf. austrodentatus y en base a la fauna de conodontos se reconoce la Zona de Yangtzeplacognathus crassus de edad darriwiliense temprana (Ordovícico Medio). Se discuten las implicaciones bioestratigráficas de estos registros, que permiten la correlación de estos niveles de la Precordillera de Mendoza con otras regiones de la Precordillera de San Juan, del Noroeste argentino y del mundo. Se brindan además algunas consideraciones paleoambientales surgidas del análisis de estos registros faunísticos y de las microfacies carbonáticas.

Revista española de paleontología, 1997

Journal of South American Earth Sciences, Jul 1, 2003

This paper describes an Upper Jurassic association of siliceous sponges from the Neuquén basin, s... more This paper describes an Upper Jurassic association of siliceous sponges from the Neuquén basin, southern Mendoza province, at Río Potimalal. Wackestones crop out in this stratigraphic section, and massive sponge-bearing micritic limestones of the La Manga formation (Plicatilis zone) have been deposited in outer shelf to slope settings. Sponges are regularly preserved as whole bodies. Their skeletons are mostly calcified, but the skeletal siliceous structure is sometime preserved. The siliceous sponges belong to the Order Hexactinosa (Class Hexactinellida, Subclass Hexasterophora) (Laocoetis sp., L. parallela, L. procumbens, Cribrospongia sp., C. clathrata, C. cucullata, Ordinatus sp., Linonema calyx) and Lyssakinosa (Poligonatyum sphaeroides). The majority of the sponge specimens correspond to the Families Cribrospongiidae (genus Cribrospongia) and Laocoetidae (genus Laocoetis). The Upper Jurassic carbonates are interpreted as deposits of a highstand systems tract, similar to other Oxfordian sequences found around the world.

Geologica Acta, Jan 11, 2003

Spicules of sponges and sclerites of chancelloriids have been collected from in situ Cambrian sec... more Spicules of sponges and sclerites of chancelloriids have been collected from in situ Cambrian sections of the La Laja Formation (San Juan Precordillera). They have also been collected from carbonate olistoliths, which were emplaced from the Cambrian units in the Early Ordovician Los Sombreros Formation (San Juan Precordillera) and Empozada Formation (Mendoza Precordillera). The Cambrian La Laja Formation sequences were deposited in a shallow carbonate platform in the eastern part of the Precordillera. The Cambrian carbonate rocks, which make up the olistoliths in the Los Sombreros and Empozada Formations, record deposition in the slope environments which developed in the western Precordillera. Cambrian Porifera and sponge-like chancelloriid assemblages are known mainly from fragments of skeletal nets, dissociated spicules and sclerites, which enable us to define two assemblages. The first assemblage of spicules was defined from the upper Lower to Middle Cambrian sequences of the La Laja Formation. This assemblage consists of a variety of stauractines and sclerites of Chancelloria WALCOTT. The family Protospongiidae is represented by triradiate prodianes, pentactines and hexactines, all belonging to Kiwetinokia WALCOTT. The second assemblage, which consists of isolated hexactines, pentactines, monaxons and skeletal nets, was defined in the Cambrian derived olistholiths of the Los Sombreros and Empozada Formations. Early hexactinellid Protospongiidae with body preservation (Diagoniella ? and Kiwetinokia) also occur. Demosponges have a very limited record in the Cambrian of the Precordillera. Anthaspidellid sponges had been reported from the La Laja Formation and now from the San Martín olistolith (Empozada Formation). The occurrences of these two assemblages of spicules and sclerites in both the Cambrian platform and slope facies of the Precordillera contribute additional data for a better understanding of the relationships between the eastern and the western facies assemblages, which developed in the Precordillera during the Cambrian. Therefore, they are useful for paleoenvironmental and paleogeographical interpretations of the Cambrian depositional framework.

Stratigraphy and Geological Correlation, 2018

The Argentine Precordillera, which was part of Gondwana in the Ordovician, is characterized by co... more The Argentine Precordillera, which was part of Gondwana in the Ordovician, is characterized by complex geological evolution, which is reflected in a series of bioevents evident from paleontological data (trilobites, conodonts, brachiopods, graptolites, etc.). An important role also belonged to calcareous algoflora as a major constituent of reefs, which is the main focus of the paper. Some calcareous algae are revised.

Spanish journal of palaeontology, Mar 1, 2022

A moderately diverse fauna of hexactinellid sponges is described f r om one Late Cambrian olistol... more A moderately diverse fauna of hexactinellid sponges is described f r om one Late Cambrian olistolith of the Los Sombreros Formation f r om Tres Saltos Gulch in the Tontal Range,Western Precordillera, San Juan Province, Argentina. Protospongia sp., Diagonieffa? sp., Kiwetinokia, anchoring spicules, prodiaenes, diagonally arranged spicules and root tuft are pr esent. The pr eservation degree of the spicules and the patterns allow us to presume that after their death, they were transported not very far f r om the original sponges oases. The Cambrian oolitic grainstone limestones with spicules conform an olistolith which was transported and re sedimented during the Ordovician by gravity nows within a pelitic matrix of the terrigenous-carbonate talus of the Los Sombreros Formation.

Neues Jahrbuch für Geologie und Paläontologie, Jun 1, 2013

A Middle Cambrian faunule from different sections of the San Isidro region, Precordillera of Mend... more A Middle Cambrian faunule from different sections of the San Isidro region, Precordillera of Mendoza Province, western Argentina, include previously unrecorded and new material. Specimens in the collections are simple reticulosan hexactinellids determined as Diagoniella cf. cyathiformis, Diagoniella sp., (?) Diagoniella sp., indeterminate protospongioid spicule assemblages and several root tuft types. In addition a possible scleritome of Chancelloria cruceana Rusconi, 1954 is re-described and illustrated, and sclerites assigned to Archiasterella are here described for the first time.

Journal of Paleontology

The Lower–Middle Ordovician (Ibexian, Whiterockian) sedimentary rocks exposed at Rancho Las Noria... more The Lower–Middle Ordovician (Ibexian, Whiterockian) sedimentary rocks exposed at Rancho Las Norias includes the informally named Las Norias formation, which consists of an intercalation of carbonate and clastic sediments with abundant marine fauna. These deposits occur as the most austral sedimentary rocks of Ordovician age for Laurentia, providing a critical link to understand the distribution of Ordovician marine faunas of North America. An investigation of the gastropod fauna from the upper portion of the Las Norias formation, Sonora, Mexico, is undertaken for the first time. The gastropod assemblage includes Maclurites acuminatus, ?Monitorella sp., Lecanospira sp., Malayaspira aff. M. rugosa, Lophospira perangulata, and Hormotoma? sp. This assemblage indicates a paleogeographic relationship with Laurentia, including the USA (Nevada), Canada (British Columbia, Newfoundland), Greenland, and the Argentine Precordillera.

Acta geológica lilloana, 1981

Spanish Journal of Palaeontology, 2022

A moderately diverse fauna of hexactinellid sponges is described f r om one Late Cambrian olistol... more A moderately diverse fauna of hexactinellid sponges is described f r om one Late Cambrian olistolith of the Los Sombreros Formation f r om Tres Saltos Gulch in the Tontal Range,Western Precordillera, San Juan Province, Argentina. Protospongia sp., Diagonieffa? sp., Kiwetinokia, anchoring spicules, prodiaenes, diagonally arranged spicules and root tuft are pr esent. The pr eservation degree of the spicules and the patterns allow us to presume that after their death, they were transported not very far f r om the original sponges oases. The Cambrian oolitic grainstone limestones with spicules conform an olistolith which was transported and re sedimented during the Ordovician by gravity nows within a pelitic matrix of the terrigenous-carbonate talus of the Los Sombreros Formation.

Neues Jahrbuch für Geologie und Paläontologie - Monatshefte, 2006

... and Pseudokainella sp.), small linguliform brachio-pods and the sponge material described her... more ... and Pseudokainella sp.), small linguliform brachio-pods and the sponge material described herein (Ricci & Villanueva 1969; Tortello et al ... from the Orcomato Formation is housed at the Paleontological Collection of the Facultad de Ciencias Naturales and Instituto Miguel Lillo as ...

Journal of Paleontology, 1994

Anthaspidellid sponges are reported from the La Laja Formation in the Chica de Zonda Range in the... more Anthaspidellid sponges are reported from the La Laja Formation in the Chica de Zonda Range in the Precordillera Oriental, Argentina. These are generically unidentifiable fragments of trabs and more or less well-defined dendroclone spicules. They occur as skeletal elements in small transported fragments and are the only Cambrian occurrence of anthaspidellids known thus far from South America.Walcott (1920) proposed to include an array of dissociated spicules, including triradiate prodiaenes, hexactines, and probable monactine spicules, in the genus Kiwetinokia. Assemblages tentatively identified as Kiwetinokia utahensis? Walcott, 1920, are reported from the Estancia San Martin Formation, of latest Early Cambrian and early Middle Cambrian age from San Isidro Gulch near Mendoza. Similar spicule assemblages occur in the La Laja Formation from the Chica de Zonda Range, in the Precordillera Oriental near San Juan, and in the Los Sombreros Formation in the Tontal Range of the Precordillera...