Ferigolo J.,Seccao de Paleontologia |
Meneghel M.,Institute Ecologia y Ciencias Ambientales |
Laurin M.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments
Historical Biology | Year: 2012
The earliest undisputed crown-group amniotes date back to the Late Carboniferous, but the fossil record of amniotic eggs and embryos is very sparse, with the oldest described examples being from the Triassic. Here, we report exceptional, well-preserved amniotic mesosaur embryos from the Early Permian of Uruguay and Brazil. These embryos provide the earliest direct evidence of reproductive biology in Paleozoic amniotes. The absence of a recognisable eggshell and the occurrence of a partially articulated, but well-preserved embryo within an adult individual suggest that mesosaurs were viviparous or that they laid eggs in advanced stages of development. Our finds represent the only known documentation of amniotic embryos in the Paleozoic and the earliest known case of viviparity, thus extending the record of these reproductive strategies by 90 and 60 Ma, respectively. © 2012 Copyright Taylor and Francis Group, LLC.
Domenico F.C.D.,University of Sao Paulo |
Bentos-Pereira A.,Institute Ecologia y Ciencias Ambientales
Journal of Orthoptera Research | Year: 2011
This paper proposes new synonyms and combinations for species of Bolidorhynchus, Cephalocoema, Orienscopia, Pseudastroma and Scleratoscopia; phallic complexes, seminal receptacles and distributions are illustrated. Most of the synonymized species were originally described by Dr. Salvador de Toledo Piza Jr., whose types were found in the collection of the Museu da Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, São Paulo, Brasil.
Rodriguez-Gallego L.,Institute Ecologia y Ciencias Ambientales |
Masciadri S.,Institute Ecologia y Ciencias Ambientales |
Nin M.,Vida Silvestre Uruguay
Estuaries and Coasts | Year: 2012
Pollen studies and their relationship with modern vegetation facilitate paleoecological reconstructions while changes in pollen abundance are indicators of environmental fluctuations. We analyzed the relationships between recent pollen deposits in the sediments of four Uruguayan coastal lagoons and catchment vegetation and analyzed the temporal dynamics of submerged aquatic vegetation (SAV). We mapped terrestrial vegetation, sampled SAV biomass, and analyzed the pollen record in each lagoon. The sediment samples represented the last 49-76 years of deposition, and most vegetation types were well represented in the pollen records. Pollen of Chenopodiaceae, proposed as indicators of saltmarshes, decreased in the surface samples of all lagoons, possibly due to the salinity reduction promoted by precipitation changes in the region. Pollen of SAV was found in all lagoons but with gaps in the record, and a submerged vegetated phase was recorded. Simultaneous botanical and pollen analyses better captured the large fluctuations of SAV in coastal lagoons. © 2012 Coastal and Estuarine Research Federation.
Pereira G.,Institute Ecologia y Ciencias Ambientales |
Abadie M.,Federal University of Rio Grande do Sul |
Maneyro R.,Institute Ecologia y Ciencias Ambientales
Studies on Neotropical Fauna and Environment | Year: 2015
We analyzed the reproductive pattern in males of Physalaemus riograndensis (n = 276). To identify the potential breeder males (n = 100), the presence of secondary sexual characters were recorded. These males were found mainly from September to April, and two peaks of abundance were observed. Breeding activity was positively correlated with temperature, but did not correlate with rainfall. As occurs with females of P. riograndensis, the fat bodies increased synchronously with the gametogenic activity, coinciding with the period of highest reproductive activity for the species (October to April). Therefore, these structures could be used as reserves of energy for reproduction in males. © 2015 Taylor & Francis.
Masciadri S.,Institute Ecologia y Ciencias Ambientales |
Masciadri S.,Federal University of Rio Grande do Norte |
Stutz S.,CONICET |
Garcia-Rodriguez F.,Institute Ecologia y Ciencias Ambientales
Revista Brasileira de Botanica | Year: 2013
Modern pollen-vegetation relationships are the basis for any paleo-study and are especially needed to understand fossil pollen assemblages and their ecological inferences. Some authors have proposed that lakes and ponds represent the surrounding vegetation through pollen grains captured by the lake. The aim of this work was to establish the modern pollen-vegetation relationships of coastal plant communities and pollen spectra represented in the surface sediments of a coastal shallow lake, and to evaluate whether spatial heterogeneity was captured by the Lake Chaparral in Perla de Rocha, Rocha, Uruguay. Pollen grains of five surface sediment samples were analyzed and related with a stratified sampling of vegetation communities surrounding the lake. Correspondence analysis and t test were used to determine plant communities and analyze the diversity of pollen assemblages. Several plant species relevant to conservation were registered, and plant communities were differentiated: coastal forest, dunes, prairies, and wetlands. However, due to limitations in taxonomic identification level for the grains of graminoids (Poaceae, Cyperaceae) in pollen assemblages, herbaceous communities highly represented by these botanical families were inferred as open environments. Pollen spectra registered at Chaparral Lake represented local and nearby vegetation well, according to both old and new theoretical models of lakes as a catchment pollen system. Several pollen grains were good indicators of the coastal forest (Myrsine sp., Ephedra tweediana Fisch. & C. A. Mey., Lithraea sp. and Tripodanthus acutifolius (Ruiz & Pav.) Tiegh.), and dunes (Chenopodiaceae, and Ambrosia sp. and Senecio sp.). The modern pollen-vegetation relationship established in this work is similar to those registered for the southern coast of Brazil, due to a shared forest component in both vegetation and pollen spectra. These results constitute primary data for the area, and we think this system is very appropriate for the historic reconstruction of coastal vegetation, particularly the coastal forest. © 2013 Botanical Society of Sao Paulo.