ABSTRACT Implications of a new collection of lycophytes of the genera Haplostigma Seward and Pale... more ABSTRACT Implications of a new collection of lycophytes of the genera Haplostigma Seward and Paleostigma Kräusel and Dolianiti from southern Bolivia and northern Argentina are presented. Fragmented herbaceous stems of lycophytes preserved as compressions, impressions and casts come from the Middle and Late Devonian Pescado (Huamampampa), Los Monos and Iquiri formations at Mataral, Yesera, Angosto del Pescado and Balapuca. The interbedded shales and siltstones bearing the lycophytes were also examined for palynology. They yielded mostly terrestrial palynomorphs with Grandispora pseudoreticulata and other Eifelian to Givetian species and fewer microplanktonic species (i.e., acritarchs, prasinophytes, chitinozoans). At Yesera, diagnostic spores and elements of the microplankton suggest a Givetian-Frasnian up to early Famennian age for the Haplostigma beds. Moreover, presence of the same brachiopod taxon in the Haplostigma intervals at Yesera Dique (palynologically barren) and Yesera Centro supports their correlation. This new information supports terrestrial connections between these Bolivian and Argentine areas and other regions of South America in the Eifelian – Givetian Afrosouthamerican Subrealm, which extended up to the early Famennian.
ABSTRACT Globular phytoliths have been mainly assigned to palms, woody trees, and other monocotyl... more ABSTRACT Globular phytoliths have been mainly assigned to palms, woody trees, and other monocotyledon families from tropical regions. The lack of detailed descriptions of this phytolith morphology and its correct assignments to particular groups could lead to erroneous interpretations of phytolith records. In order to improve paleobotanical interpretations of phytoliths records, we analyzed the phytolith content and described the quantitative and qualitative characters of globular phytoliths of Arecaceae, Bromeliaceae, Cannaceae, Marantaceae, Orchidaceae, Strelitziaceae, and Zingiberaceae species from Argentina. Phytoliths were extracted by calcination and multivariate analyses were used to analyze their taxonomic relevance. Phytolith assemblages allowed the differentiation 1) among Zingiberales species; 2) among Arecaceae species; 3) between Orchidaceae, Arecaceae, and Bromeliaceae families; and 4) between Zingiberales and the rest of the groups. The study of distinguishing features of globular morphologies (such as size, roundness, reniformity, number of spines, spine length, and density of spines) allowed the discrimination between two Arecaceae subfamilies, and among Bromeliaceae, Cannaceae, and Zingiberaceae families. This work showed the importance of both analyses (phytolith assemblages and phytolith morphometric) in the identification of groups at different levels and represented the first detailed and comparative description of globular phytoliths of palms and other monocotyledons from Argentina.
A palaeoecological study of a standing Late Triassic forest containing 150 silicified stumps from... more A palaeoecological study of a standing Late Triassic forest containing 150 silicified stumps from the Río Blanco Formation of Mendoza province, Argentina is described. A mapped portion of the forest floor provides quantitative data—tree density, mean separation of ...
... CHRISTOPHER M. BERRY * ,* , EDUARDO MOREL , JAIRO MOJICA and CARLOS VILLARROEL ... larger ver... more ... CHRISTOPHER M. BERRY * ,* , EDUARDO MOREL , JAIRO MOJICA and CARLOS VILLARROEL ... larger version (30K): [in this window] [in a new window], Figure 2. Location map of the two fossil localities mentioned in this report: (1) Puerto Arepas; (4) Quebrada Potrero Rincón. ...
... is consistent both with one based on brachiopods from exposures to the west of Tarabuco (Rach... more ... is consistent both with one based on brachiopods from exposures to the west of Tarabuco (Racheboeuf & Branisa, 1985; Benedetto, Sanchez & Brussa, 1992) and on brachiopods and graptolites (Davila & Rodriguez, 1967). In summarizing all palaeontological evi-dence, Berry ...
ABSTRACT Implications of a new collection of lycophytes of the genera Haplostigma Seward and Pale... more ABSTRACT Implications of a new collection of lycophytes of the genera Haplostigma Seward and Paleostigma Kräusel and Dolianiti from southern Bolivia and northern Argentina are presented. Fragmented herbaceous stems of lycophytes preserved as compressions, impressions and casts come from the Middle and Late Devonian Pescado (Huamampampa), Los Monos and Iquiri formations at Mataral, Yesera, Angosto del Pescado and Balapuca. The interbedded shales and siltstones bearing the lycophytes were also examined for palynology. They yielded mostly terrestrial palynomorphs with Grandispora pseudoreticulata and other Eifelian to Givetian species and fewer microplanktonic species (i.e., acritarchs, prasinophytes, chitinozoans). At Yesera, diagnostic spores and elements of the microplankton suggest a Givetian-Frasnian up to early Famennian age for the Haplostigma beds. Moreover, presence of the same brachiopod taxon in the Haplostigma intervals at Yesera Dique (palynologically barren) and Yesera Centro supports their correlation. This new information supports terrestrial connections between these Bolivian and Argentine areas and other regions of South America in the Eifelian – Givetian Afrosouthamerican Subrealm, which extended up to the early Famennian.
ABSTRACT Globular phytoliths have been mainly assigned to palms, woody trees, and other monocotyl... more ABSTRACT Globular phytoliths have been mainly assigned to palms, woody trees, and other monocotyledon families from tropical regions. The lack of detailed descriptions of this phytolith morphology and its correct assignments to particular groups could lead to erroneous interpretations of phytolith records. In order to improve paleobotanical interpretations of phytoliths records, we analyzed the phytolith content and described the quantitative and qualitative characters of globular phytoliths of Arecaceae, Bromeliaceae, Cannaceae, Marantaceae, Orchidaceae, Strelitziaceae, and Zingiberaceae species from Argentina. Phytoliths were extracted by calcination and multivariate analyses were used to analyze their taxonomic relevance. Phytolith assemblages allowed the differentiation 1) among Zingiberales species; 2) among Arecaceae species; 3) between Orchidaceae, Arecaceae, and Bromeliaceae families; and 4) between Zingiberales and the rest of the groups. The study of distinguishing features of globular morphologies (such as size, roundness, reniformity, number of spines, spine length, and density of spines) allowed the discrimination between two Arecaceae subfamilies, and among Bromeliaceae, Cannaceae, and Zingiberaceae families. This work showed the importance of both analyses (phytolith assemblages and phytolith morphometric) in the identification of groups at different levels and represented the first detailed and comparative description of globular phytoliths of palms and other monocotyledons from Argentina.
A palaeoecological study of a standing Late Triassic forest containing 150 silicified stumps from... more A palaeoecological study of a standing Late Triassic forest containing 150 silicified stumps from the Río Blanco Formation of Mendoza province, Argentina is described. A mapped portion of the forest floor provides quantitative data—tree density, mean separation of ...
... CHRISTOPHER M. BERRY * ,* , EDUARDO MOREL , JAIRO MOJICA and CARLOS VILLARROEL ... larger ver... more ... CHRISTOPHER M. BERRY * ,* , EDUARDO MOREL , JAIRO MOJICA and CARLOS VILLARROEL ... larger version (30K): [in this window] [in a new window], Figure 2. Location map of the two fossil localities mentioned in this report: (1) Puerto Arepas; (4) Quebrada Potrero Rincón. ...
... is consistent both with one based on brachiopods from exposures to the west of Tarabuco (Rach... more ... is consistent both with one based on brachiopods from exposures to the west of Tarabuco (Racheboeuf & Branisa, 1985; Benedetto, Sanchez & Brussa, 1992) and on brachiopods and graptolites (Davila & Rodriguez, 1967). In summarizing all palaeontological evi-dence, Berry ...
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