Middle-Late Jurassic megaflora of Laguna Flecha Negra locality in Santa Cruz Province, Patagonia, and floristic assemblages of the Bahía Laura Complex
Autor: | Ana Julia Sagasti, Diego Martin Guido, Juan Leandro García Massini, Eduardo Manuel Morel, Ignacio H. Escapa |
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Rok vydání: | 2020 |
Předmět: |
010506 paleontology
biology Ecology Species diversity Araucariaceae Geology Plant community Understory 010502 geochemistry & geophysics biology.organism_classification 01 natural sciences Floristics Equisetales Cheirolepidiaceae Isoetales 0105 earth and related environmental sciences Earth-Surface Processes |
Zdroj: | Journal of South American Earth Sciences. 100:102564 |
ISSN: | 0895-9811 |
Popis: | A Middle-Late Jurassic fossil plant assemblage is described from the Bahia Laura Complex at the Laguna Flecha Negra locality, Santa Cruz Province. The fossil assemblage is autochthonous, preserved in volcaniclastic sediments in the fringes of a geothermal landscape. Taxonomic study of the palaeoflora revealed 17 taxa. The recognized species have been previously described in Jurassic localities of Gondwana and illustrate the diversity of plant communities that lived in a volcanic setting. The dominant elements of this flora are microphyllous conifers of the families Araucariaceae and Cheirolepidiaceae. Fossil leaves of Cycadeoidales co-dominate the community. There is a low diversity and abundance of ferns. Composition of the plant community is compared to coetaneous floras of the Bahia Laura Complex to analyse geographical variations in the diversity of Middle-Late Jurassic assemblages of Santa Cruz Province, and a relative uniformity is recognized. Forest landscapes were dominated by conifer trees, with cycadeoids as small trees or shrubs. The herbaceous understory was dominated by fern communities with low species diversity; Equisetales and Isoetales appeared as subordinated elements. Microphyllous conifers and cycadophytes, as well as a low diversity of ferns, are indicative of relatively dry weather. |
Databáze: | OpenAIRE |
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