Flora Gimnospérmica de la Formación Ñirihuau (Oligoceno Tardío-Mioceno Temprano), Provincia de Río Negro, Argentina

Falaschi, Paula; Zamaloa, María del Carmen; Caviglia, Nicolás; Romero, Eva Juana Rodríguez

doi:10.5710/amgh.14.2.2012.518

Cited by 18 publications

(16 citation statements)

References 56 publications

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“…Paleofloristic reports include a Proteaceae leaf (Frenguelli, 1943), Polygonaceae fruits (Menéndez, 1960), and leaves of Araucaria (Menéndez and Caccavari, 1966). More recently, Falaschi et al (2012) studied the gymnosperms and pollen, and…”

Section: N P R E S Smentioning

confidence: 99%

The first fossil record of a giant horsetail (Equisetum, Equisetaceae) is from the Miocene of Patagonia, Argentina

Zamaloa

Cornou

Martínez

et al. 2022

andgeo

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A Miocene macroflora recovered from Ñirihuau Formation sediments exposed at Quebrada Vera site in northwesterern Patagonia, Argentina, is recorded and described for the first time. The assemblage is composed exclusively of free-sporing plants, mainly by Equisetum remains with subordinate occurrences of four fern morphotypes (represented by bi-, tri- and pinnate fronds). Equisetum imprints and molds include distinctive jointed stems with whorls of linear and basally fused leaves, numerous scars of lateral branches arranged in a radially symmetrical pattern situated at the nodes, and nodal diaphragms of up to 4 cm in diameter. The large size and regular branching of the stems link the fossils to the South American giant members of the genus and they probably represent a new fossil species. This is the first conclusive fossil record of a giant Equisetum worldwide, and consequently, it is biogeographically and evolutionarily relevant. The new findings attest that members of the giant horsetail clade were components of the Patagonian vegetation in the Miocene, implying that the age of the clade must predate that estimated from morphological and/or molecular data. The plant fossil assemblage represents part of a wetland community probably growing close to a riverside or lakeshore in coincidence with previous sedimentological estimates.

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Section: N P R E S Smentioning

confidence: 99%

The first fossil record of a giant horsetail (Equisetum, Equisetaceae) is from the Miocene of Patagonia, Argentina

Zamaloa

Cornou

Martínez

et al. 2022

andgeo

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“…Leaves of A. lefipanensis also differ markedly from those of the previously known Patagonian fossil species A. grandifolia Feruglio, A. pararaucana Panti, and A. nathorsti Dusén (Table ; Dusén, ; Berry, ; Feruglio, ; Menéndez and Caccavari, ; Del Fueyo and Archangelsky, ; Panti et al., ; Falaschi et al., ; Ohsawa et al., ). The Early Cretaceous A. grandifolia Feruglio has triangular‐lanceolate leaves similar to those found in Araucaria section Intermedia , although Del Fueyo and Archangelsky () classified this species as part of the section Araucaria because its leaves are more imbricated than those of the extant species of section Intermedia .…”

Section: Discussionmentioning

confidence: 83%

“…The Eocene‐Oligocene species, A. pararaucana Panti, has a leaf morphology similar to that of the O‐shaped morphology of A. lefipanensis , but differ in size, and stomatal orientation (Table , Panti et al., ). Finally, the Oligocene‐Miocene A. nathorstii Dusén has leaves that are similar to the new species in shape and stomatal morphology, but that are larger, and associated cone scale complexes with a different general outline and degree of wing development (Table ; Dusén, ; Berry, ; Menéndez and Caccavari, ; Falaschi et al., ; Ohsawa et al., ).…”

Section: Discussionmentioning

confidence: 99%

“…One consisting of only a change in leaf size (hereafter type I dimorphism), similarly to what occurs in the extant South American species Araucaria angustifolia (Bertol.) Kuntze, and in the extinct species Araucaria bladenensis Berry, A. alexandrensis Cantrill and Falcon‐Lang, Araucarites marshalli Edwards, and A. nathorstii Dusén (Tables ; Dusén, ; Berry, ; Edwards, ; Berry, ; Menéndez and Caccavari, ; Cantrill and Falcon‐Lang, ; Falaschi et al., ; Stults et al., ). The second type of dimorphism is characterized by two distinct leaf shapes (hereafter, type II dimorphism).…”

Section: Discussionmentioning

confidence: 99%

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Araucaria lefipanensis(Araucariaceae), a new species with dimorphic leaves from the Late Cretaceous of Patagonia, Argentina

Andruchow‐Colombo

Escapa

Cúneo

et al. 2018

American J of Botany

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The leaf dimorphism of A. lefipanensis is similar to that of extant A. bidwillii, where dimorphism is considered to be related to seasonal growth. The leaf dimorphism in A. lefipanensis is consistent with the paleoclimatic and paleoenvironmental reconstructions previously suggested for the Lefipán Formation, which is thought to have been a seasonal subtropical forest. The new species shows evidence of mosaic evolution, with cone scale complexes morphologically similar to section Eutacta and leaves similar to the sections of the broad-leaved clade, constituting a possible transitional form between these two well-defined lineages. More complete plant concepts, especially those including both reproductive and vegetative remains are necessary to understand the evolution of ancient plant lineages. This work contributes to this aim by documenting a new species that may add to the understanding of the early evolution of the sections of Araucaria.

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“…La unidad está expuesta en una ancha faja NNO limitada por corrimientos. Incluye sedimentitas clásticas, calizas con ostrácodos, tobas y brechas tobáceas con niveles carbonosos ricos en restos de angiospermas, en especial Nothofagaceae (Caviglia & Zamaloa, 2014), y gimnospermas (Falaschi et al, 2012), depositadas en un medio fluviolacustre con conexiones marinas ocasionales. Los afloramientos aparecen normalmente plegados con anticlinales y sinclinales como en el cerro La Buitrera (Giacosa & Heredia, 2005;Paredes et al, 2009) (Fig.…”

Section: Minas De Petróleo En La Buitreraunclassified

Sobral y la geología del Ã?irihuau

Ottone

2016

RMLP

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Sobral fue el Jefe de la comisión que exploró y desarrolló dos pozos petroleros en el Ñirihuau desde fin de 1932 a mediados de 1934. Durante ese lapso reconoció la estructura de la comarca del cerro La Buitrera, realizando también observaciones menores entre Ingeniero Jacobacci y Pilcaniyeu, la zona del río Foyel y los alrededores de Bariloche, además de colaborar en la descripción de las perforaciones Ñirihuau 1 y 2. El detalle de sus interpretaciones sobre la geología de la zona permaneció inédito en sus libretas de campo. Se comentan las notas y dibujos insertos en ellas y reproducen parcialmente, poniendo de relieve su valor histórico y geológico.

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Flora Gimnospérmica de la Formación Ñirihuau (Oligoceno Tardío-Mioceno Temprano), Provincia de Río Negro, Argentina

Cited by 18 publications

References 56 publications

The first fossil record of a giant horsetail (Equisetum, Equisetaceae) is from the Miocene of Patagonia, Argentina

The first fossil record of a giant horsetail (Equisetum, Equisetaceae) is from the Miocene of Patagonia, Argentina

Araucaria lefipanensis(Araucariaceae), a new species with dimorphic leaves from the Late Cretaceous of Patagonia, Argentina

Sobral y la geología del Ã?irihuau

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