Rodolfo Dino

Morphology and ultrastructure of elater-bearing pollen from the Albian to Cenomanian of Brazil and Ecuador: implications for botanical affinity

Abstract The morphological range of elaterate pollen grains is reassessed on the basis of detailed light, scanning electron and transmission electron microscope analyses of representatives from upper Albian–Cenomanian sections in Brazil and Ecuador. Included in the elaterate complex are Alaticolpites , Elaterocolpites , Elateroplicites , Elateropollenites , Elaterosporites , Galeacornea , Pentapsis , Regalipollenites , Senegalosporites and Sofrepites . All possess elater-like protuberances, but are otherwise morphologically disparate. Ultrastructural analyses of three taxa, Elateroplicites africaensis , Elaterosporites klaszii and Sofrepites legouxiae , reveals granular-alveolate ektexine and wall organization comparable to that of gnetalean pollen and to fossil Equisetosporites / Ephedripites . A correlation exists between diversity/frequency levels of Elaterates and successive events in opening of the northern part of the South Atlantic Ocean. This is interpreted to reflect rapid diversification of the gnetalean sources of elaterate pollen in response to climatic perturbations associated with opening and enlargement of this ocean. The introduction and diversification of Elaterates coincides with early phases of angiosperm diversification, whereas extinction of the Elaterates-producing gnetalean group at the close of the Cenomanian heralded the rise to dominance of angiosperms in low latitudinal areas fringing the northern South Atlantic.

Late carboniferous palynology from the itararé subgroup (paraná basin) at araçoiaba da serra, São Paulo State, brazil

Abstract Core samples from the A‐IG‐85 well and four outcrops located in South Aracoiaba da Serra, Sao Paulo State, Brazil, have been palynologically investigated. Diverse and well‐preserved palynomorphs, including seventy‐three species of spores, monosaccate, disaccate and taeniate pollen grains, and one species of incertae sedis have been recognized. Among them, sixty species are systematically described including thirty‐four species of spores, twenty‐five pollen grains and one incertae sedis. Eleven species from the Brazilian Parana Basin are published for the first time: Granulatisporites triconvexus Staplin 1960, Dictyotriletes muricatus (Kosanke) Smith & Butterworth 1967, Vallatisporites punctatus (Marques‐Toigo) comb, nov., Cristatisporites rollerii Ottone 1989, Bascaudaspora canipa Owens 1983, Spelaeotriletes triangulas Neves & Owens 1966, Psomospora detecta Playford & Helby 1968, Florinites occultus Habib 1966, Potonieisporites barrelis Tiwari 1965, Costatascyclus crenatus Felix & Burbridge emend...

The upper Paleozoic miospore genus Spelaeotriletes Neves and Owens, 1966, and constituent Gondwanan species

The upper Paleozoic miospore genus Spelaeotriletes Neves and Owens, 1966 is reviewed as a morpho-taxonomic entity and vis-a-vis other similarly constructed (pseudosaccate) genera — Geminospora Balme, 1962, Grandispora Hoffmeister, Staplin, and Malloy, 1955, Rhabdosporites Richardson, 1960, and Retispora Staplin, 1960. Detailed studies of numerous, mainly topotype specimens of Spelaeotriletes ybertii (Marques-Toigo, 1970) Playford and Powis, 1979 from the Lower Permian of Uruguay result in its re-diagnosis, in conjunction with a survey of its exclusively Gondwanan occurrences, particularly in South American strata extending from the Upper Carboniferous (Westphalian) into the Lower Permian, and also in Australian strata of approximately equivalent age. The characteristics of other species of Spelaeotriletes reported from upper Paleozoic deposits of Gondwana are discussed, as are their temporal representations in various broad regions of the supercontinent (South America, North Africa, Australia). These species include two, perhaps three, that, like Spelaeotriletes triangulus/arenaceus, are known also from Euramerica — S. balteatus (Playford, 1963) Higgs, 1996, S. pretiosus (Playford, 1964) Utting, 1987, and possibly S. owensii Loboziak and Alpern, 1978. Other species, such as S. benghaziensis Loboziak and Clayton, 1988, S. giganteus Loboziak and Clayton, 1988, and S. vibrissus Playford and Satterthwait, 1988, have, on present knowledge, exclusively Gondwanan occurrences. S. queenslandensis Jones and Truswell, 1992, known only from Upper Carboniferous strata of northeastern Australia, is formally reassigned on sculptural grounds to Grandispora. Not unexpectedly in a paleogeographic perspective, North Africa and South America are more closely allied with each other than with Australia in terms of shared species of Spelaeotriletes.

Earliest Taeniate Bisaccates from the Amazon basin are not older than Westphalian.

Abstract The so-called “Namurian” taeniate bisaccates newly reported from the Amazon Basin of northern Brazil (Marques-Toigo et al. 1995) are demonstrated to be not older than Westphalian in the light of revised foraminiferal and palynological evidence. Nevertheless, marine microfossil data supports a slightly older age assignment (Westphalian A-B) than miospores (Westphalian C). Correlations of Carboniferous pollen assemblages in the Amazon Basin with those from the Parana Basin, in southeastern and southern Brazil, are hindered by the absence of diagnostic marine microfossils and coeval mid-Carboniferous strata in the latter.

Cenozoic distribution of Ephedripites Bolkhovitina (1953) ex Potonié (1958) emend. Krutzsch (1961) in Brazil

Abstract Here we present a critical revision of the occurrence of Ephedripites pollen grains during the Cenozoic of Brazil along with a new interpretation of the palaeo-biogeographical implications regarding the distribution of E. eocenipites, E. fusiformis, E. lusaticus and E. claricristatus (=E. tertiarius) in continental and marine sediments. Morphological features of these taxa, in general terms, differ from those of Cretaceous forms by the reduced number of plicae and thinner ribs. The revision of the Brazilian literature of Ephedripites point to a Paleocene distribution restricted to 30° S palaeo-latitude, whereas from the Eocene to the Pliocene, this genus is found in higher palaeo-latitudes of south-eastern and southern Brazil, attesting its occurrence in vegetation on dry or well drained soils.

The Pliocene–Pleistocene palynology of the Negro River, Brazil

ABSTRACT Palynological studies in central Amazonia are scarce, especially those concerned with resolving the age of sedimentary deposits. A recent opportunity allowed the stratigraphical and palynological study of a sedimentary unit below the Negro Rivers current channel. Age was constrained by the basal occurrence of Alnipollenites verus, and the top occurrence of Grimsdalea magnaclavata and Paleosantalaceaepites cingulatus, as late Pliocene to early Pleistocene. Here, we provide additional details on the palynostratigraphy and biodiversity of this deposit. Samples yielded 95 palynomorphs that included 58 pollen and 26 spore species, of which we identified botanical affinities with 26 angiosperm, one gymnosperm and four pteridophyte families. Twenty-five new taxa are erected, from which we recognise five angiosperm genera, namely Pacourina/Vernonia (Asteraceae), Myrsine? (Myrsinaceae), Symmeria (Polygonaceae), Faramea (Rubiaceae) and Schefflera (Araliaceae), plus a possible Marcgraviaceae pollen. These taxa, along with the majority of the recovered assemblage, are indicative of Amazonian lowland floras.

Avaliação do potencial gerador de petróleo da seção Aptiana-Albiana da Bacia de Sergipe, integrando análises palinofaciológicas e dados de geoquímica orgânica

Data presented in this investigation refer to studies integrating palynofacies and organic geochemistry analyses that were performed on 51 samples of PEC-41-SE-9 well, located in the Sergipe Basin, Eastern Brazilian continental margin. It was evaluated the potential for oil generation, identifying the type and degree of maturation of the organic matter. Optical analyzes show that the organic matter is composed in greater proportion by amorphous organic matter in good preservation, with high fluorescence. It also presents a 67% average concerning the total composition of the kerogen. The phytoclasts usually are well preserved in almost all the section. The palynomorphs are composed of an association, predominantly, of spores and pollen grains of genus Classopollis, featuring a predominantly arid to semi-arid climate environment at deposition time. Presence of the dinoflagellate in the upper section displays the first marine ingressions that happened in the end of Aptian. Based on the qualitative and quantitative results of kerogen, it was possible to characterize three distinct palynofacies, in which the palynofacies I had the best features for quality and preservation of organic matter. The results show total organic carbon values up to 6.39% and Rock-Eval pyrolysis data pointed to the type II kerogen rich in organic matter suitable for the formation of hydrocarbon accumulations. The hydrogen index is found between 200 and 550 mg HC/g of total organic carbon, which shows good potential for oil and gas generation. Spore color index data conclude that the organic matter is found predominantly on the immature maturation phase, with SCI values of 4.0 to 4.5, corroborating with data of maximum temperature, of up to 432°C.