Tese Silane Aparecida Ferreira Da Silva.Pdf

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INSTITUTO NACIONAL DE PESQUISAS DA AMAZÔNIA UNIVERSIDADE FEDERAL DO AMAZONAS PROGRAMA DE PÓS-GRADUAÇÃO EM BIOLOGIA TROPICAL E RECURSOS NATURAIS DA AMAZÔNIA

PALINOLOGIA DO NEÓGENO DA BACIA DO ALTO SOLIMÕES, AMAZÔNIA OCIDENTAL, BRASIL: ASPECTOS SISTEMÁTICOS, BIOESTRATIGRÁFICOS E PALEOECOLÓGICOS

SILANE APARECIDA FERREIRA DA SILVA

Manaus, Amazonas FEVEREIRO, 2008

SILANE APARECIDA FERREIRA DA SILVA

PALINOLOGIA DO NEÓGENO DA BACIA DO ALTO SOLIMÕES, AMAZÔNIA OCIDENTAL, BRASIL: ASPECTOS SISTEMÁTICOS, BIOESTRATIGRÁFICOS E PALEOECOLÓGICOS

Dr. MARIA LUCIA ABSY Dr. CARLOS A. JARAMILLO

Tese apresentada ao PIPG-BTRN como parte dos requisitos para obtenção do título de Doutor em

Ecologia, área de concentração em Paleoecologia.

Manaus, Amazonas Fevereiro, 2008

ii S586 Silva, Silane Aparecida Ferreira da Palinologia do Neógeno da Bacia do Alto Solimões: Aspectos sistemáticos, bioestratigráficos e paleoecológicos / Silane Aparecida Ferreira da Silva– Manaus: INPA/UFAM, 2008. viii, 182f. il.

Tese (Doutorado) - INPA/UFAM, Manaus, 2008 Orientador: Maria Lúcia Absy Co-orientador: Carlos A. Jaramillo Área de concentração: Ecologia.

1. Paleopalinologia 2. Paleoecologia 3. Bioestratigrafia. I. Palinologia do Neógeno da Bacia do Alto Solimões: Aspectos sistemáticos, bioestratigráficos e paleoecológicos

CDD 19. Ed. 582.0463

Sinopse

Foram estudadas 41 amostras de sedimentos da Fm. Solimões de duas sondagens realizadas no Alto Solimões com o objetivo de obter dados bioestratigráficos e paleoecológicos utilizando-se a palinologia. Como resultado encontrou-se que muitos marcadores estratigráficos utilizados, apresentam-se com baixa freqüência (<3% da associação), sendo necessário, portanto, a utilização de novos marcadores. Uma associação palinológica típica de ambiente de água doce foi encontrada, em contraposição a uma hipótese marinha sugerida para a Amazônia no Neógeno. Muitos gêneros/famílias foram registrados nesse estudo, sendo de suma importância para o uso dessa informação em calibração de relógios moleculares.

Palavra-chaves: Mioceno-Plioceno, pólen e esporos, Formação Solimões, bioestratigrafia quantitativa.

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Aos meus pais, irmãos e esposo por representar a materialização da bondade Divina em minha vida, dedico.

iv AGRADECIMENTOS

Gostaria de agradecer a duas agências federais de apoio ao desenvolvimento científico: CAPES e CNPq pela concessão de bolsas de estudo tanto no Brasil como no exterior.

Aos meus orientadores: Profa. Dra. Maria Lúcia Absy pelo acompanhamento científico durante o mestrado e doutorado; e ao Dr. Carlos Jaramillo, pelos constantes porquês, e por me fazer compreender que a ciência é feita de olhar as coisas sempre por outros ângulos.

À PDVSA, PETROBRÁS e ECOPETROL e Carina Hoorn pela disponibilização dos holótipos e parátipos de muitos grãos identificados durante esse estudo.

À Dra. Cláudia Keller, coordenadora do curso de Ecologia, pela eficiência em agilizar os processos relacionados a bolsa de estágio no exterior.

Aos Drs. Edgardo Latrubesse, Mario Cozzuol, Jackson da Paz e Fátima Praxedes Leite, pelas frutíferas discussões sobre geologia, paleontologia e palinologia da Amazônia.

Ao Dr. Fernando Burgos e Gert Wothje do DNPM, pela facilidade em obtenção e liberação para estudo no exterior de amostras de sedimentos.

Aos amigos do grupo de Bioestratigrafia do ICP- Instituto Colombiano de Petróleo e grupo de paleontologia do STRI pela incondicional ajuda e amizade ao longo desses anos, em especial, a Carolina Vargas, D. Milton Rueda e Dr. Vladimir Torrez.

Pelo apoio logístico do Smithsonian Tropical Research Institute, principalmente pela eficiência dos amigos da biblioteca na obtenção de trabalhos científicos. Gracias, mi amigo Angel!

v À Sra. Gilda Fernandes, bibliotecária do CPRM-Manaus, pelo profissionalismo experiente de saber exatamente a localização dos mais antigos e não-utilizados relatórios internos contidos na biblioteca do CPRM.

À Millerlandy Romero, pela amizade, pelos papers, pelos index cards, pela confecção dos diagramas polínicos e pelos deliciosos almoços caseiros que me fizeram sentir em casa durante minha estadia no Panamá.

À MsC. Carlos Francisco, pelas descontraídas discussões em biogeografia e interpretação de dados moleculares de trabalhos publicados sobre a Amazônia além da ajuda com o enigmático programa End Note.

À MsC. Paula Sucerquia e Hugo Cauper, pela ajuda com os perfis de poços e alguns gráficos.

Ao amigo Enrique Moreno pela paciência e disponibilidade em discutir sobre morfologia e afinidade natural dos grãos que encontrava em meu material.

À Dr. Mauro Toledo e MsC. Alex Correa, pela ajuda nas análises multivariadas, que infelizmente não entraram nessa tese, mas que farão parte do meu próximo manuscrito. Ao Mauro também pela correção do Abstract. Qualquer reclamação a culpa é dele!

À Jean Caminha pelos ensinamentos de velejador, de que: os barcos estão mais seguros no porto mas não foram feitos pra isso; não há mares tranqüilos e que, principalmente, não há vento bom para quem não sabe para onde vai.

Resumo

A Amazônia apresenta uma grande diversidade biológica distribuída em uma grande e heterogênea área geográfica. Para explicar essa alta riqueza muitas hipóteses têm sido sugeridas. Entretanto, poucos estudos sobre a história geológica e paleontológica têm sido desenvolvidos com o objetivo de se conhecer aspectos paleoecológicos da Amazônia em tempos passados. Devido a essa carência em estudos paleontológicos, encontram-se disponíveis na literatura contraditórias hipóteses que tentam explicar a evolução do ambiente amazônico bem como determinados aspectos biogeográficos. Essa tese foi desenvolvida com o objetivo de levantar aspectos gerais da ecologia e estratigrafia da Amazônia usando-se como ferramenta a palinologia. Entretanto, foi observado que a nomenclatura palinológica empregada na literatura, e amplamente usada em trabalhos especializados, necessitava de uma detalhada revisão. Para esse estudo foram usadas 41 amostras de sedimentos de duas sondagens realizadas na região do Alto Solimões. Sistematicamente, foram descritas 112 espécies, cerca de 51 novas espécies, 7 novas combinações foram propostas. Botanicamente, muitos gêneros foram registrados pela primeira vez na Amazônia, sendo que o uso dessas informações são importantes para calibração de relógios moleculares. Estratigraficamente, um novo zoneamento para o Plioceno foi proposto usando-se o método de Associações unitárias para definir as novas associações. Em relação ao ambiente, pode-se afirmar que predominou o sistema fluvial altamente dinâmico, sem nenhum registro indicando ambiente costeiro ou marinho. Desde o Mioceno/Plioceno muitos gêneros de plantas presentes na Amazônia atualmente já estavam presentes, indicando que a diversidade atual pode ser resultado de uma longa história de estabilidade ambiental.

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Abstract

The Amazon region harbors high biologic diversity distributed throughout a huge and heterogeneous area. Many hypotheses try to explain this high diversity present in Amazonia, as well as in other tropical rainforests. However, few studies about the geological and paleontological histories have been developed in order to find out paleoecological patterns of the Amazonian history. In reason of the scarcity of paleontological studies, some contradictory hypotheses that try to explain the evolution of the Amazonian environment, as well as some biogeographical aspects, are available in the literature. The present study was conducted in order to find out some general aspects of the ecology and stratigraphy of the Amazonia using Palynology as the main tool. However, it was observed that the palynological nomenclature used presently needed a review. Forty-one samples from 2 cores located in the Upper Solimões Basin were analyzed. One hundred twelve species were systematically described, with 51 being new species, and 7 new combinations were proposed. Many genera were recorded for the first time in Amazonia. This kind of information is useful to calibrate molecular clocks. New stratigraphic zones were proposed for the Pliocene using the Unitary Association method, and the environment was interpreted as a highly dynamic freshwater system, with no evidence of coastal or marine influence. Many plant genera that exist today were present since the Miocene/Pliocene, suggesting that the high modern biodiversity could be the result of a long history of environmental stability.

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Sumário

Resumo ...... vii

Abstract ...... viii

Lista de Tabelas ...... 10

Lista de Figuras...... 11

1.0 Introdução...... 13

1.1- Considerações Gerais...... 13

1.2- Registros da “Paleoamazônia”...... 13

2.0 Objetivos...... 16

2.1 Objetivo geral...... 16

2.2 Objetivos específicos ...... 16

3.0- Bacia do Solimões...... 17

3.1- Formação Solimões ...... 19

3.1.1 - Ambientes de deposição ...... 24

3.1.2- Palinoestratigrafia da Formação Solimões ...... 27

4.0 Material e Métodos ...... 29

4.1 Área de estudo...... 29

4.1.1- Poço 1AS-27-AM...... 30

4.1.2- Poço 1AS-19-AM...... 32

4.2 Preparação das amostras e contagem dos grãos...... 34

4.3 Análise dos dados...... 35

4.3.1- Sistemática, taxonomia, afinidades botânica e ecológicas dos

esporomorfos...... 35

4.3.2- Bioestratigrafia...... 37

9 5.0 Resultados e discussões ...... 39

5.1 Sistemática...... 39

5.2- Bioestratigrafia ...... 40

5.2.1- Bioestratigrafia tradicional ...... 40

5.2.2- Bioestratigrafia quantitativa ...... 49

5.3- Paleoecologia ...... 53

5.3.1- Relação abundância e raridade na composição palinológica...... 53

5.3.2- Famílias de angiospermas predominantes...... 57

5.3.3 Primeiros registros de famílias e gêneros na Amazônia...... 62

5.3.4 Diversidade da Amazônia durante o Neógeno ...... 63

6.0 Conclusões...... 66

7.0 Referências...... 67

8.0 Anexos...... 72

Lista de Tabelas

Tabela 1: Zonas estabelecidas por Hoorn (1993) com as associações de

espécies...... 28

Tabela 2: Zonas palinológicas estabelecidas para Venezuela e Amazônia. .44

Tabela 3: Tabela mostrando a composição de cada UA. Em amarelo está a

associação típica da UA2. Em azul a espécie encontrada somente na

UA1. Na seção intermediária estão as espécies das UA1/2. A primeira

coluna corresponde aos números contidos nos gráficos orientados e não

orientados...... 51

Tabela 4: Afinidade botânica e hábito de alguns esporos que apresentaram

abundância na associação...... 55

10 Tabela 5: Tabela com alguns tipos polínicos encontrados e suas informações

botânicas...... 56

Tabela 6: Afinidade botânica de alguns fósseis...... 61

Tabela 7: Informações botânicas das famílias/Gêneros registrados pela

primeira vez na Amazônia...... 62

Lista de Figuras

Figura 1: Localização aproximada das Bacias do Estado do Amazonas...... 18

Figura 2: Delimitação das sub-bacias na Bacia do Solimões. Modificado de

Silva, 1987...... 18

Figura 3: Seção de referência da Fm Solimões. Extraída e modificada de

Caputo et al. (1971)...... 21

Figura 4: Seção-tipo da Fm. Solimões. Extraído e modificado de Eiras et al.

(1994)...... 22

Figura 5: Seção-referência da Fm. Solimões. Extraída e modificada de Eiras

et al. (1994)...... 23

Figura 6: Modelo de depósito fluvial com fácies de planície de inundação,

típicos da Fm Solimões...... 27

Figura 7: Mapa de localização onde os poços foram perfurados...... 30

Figura 8: Perfil estratigráfico do poço 1AS-27-AM juntamente com perfis de

raios-gama e resistividade...... 31

Figura 9: Perfil estratigráfico do poço 1AS-19-AM juntamente com perfis de

raios-gama e resistividade...... 33

11 Figura 10: Correlação estratigráfica usando a bioestratigrafia tradicional da

região...... 41

Figura 11: Carta de distribuição do 1AS-27-AM ...... 47

Figura 12: Carta de distribuição do 1AS-19-AM...... 48

Figura 13: Correlações estratigráficas usando-se o método de Associação

Unitária ...... 49

Figura 14: A) gráfico não Orientado, onde os números correspondem as

espécies (vértices) e as setas em azul (arestas) correspondem a relação

de co -ocorrência entre as espécies, B) gráfico Orientado, onde os

números correspondem as espécies (vértices) e as setas em vermelho

(arcos) correspondem a relação de superposição entre as espécies.....51

Figura 15: Gráfico de freqüência (%) de esporos, famílias de angiospermas e

gimnospermas encontradas no Poço 1AS-27-AM...... 54

Figura 16: Gráfico de freqüência de esporos, famílias de angiospermas e

gimnospermas encontradas no Poço 1AS-19-AM...... 54

Figura 17: Diagrama palinológico com abundância de esporomorfos no poço

1AS-27-AM...... 59

Figura 18: Diagrama palinológico com abundância de esporomorfos a nível

de família/gênero no poço 1AS-19-AM...... 60

1.0 Introdução

1.1- Considerações Gerais

Existem duas maneiras de estudar o passado de florestas tropicais. Uma por meio de análise molecular e a outra por meio de paleontologia, sendo a primeira mais moderna, mas dependente da segunda. Isso se deve ao fato de que a análise molecular usa dados obtidos pela paleontologia tais como, estado de caracteres morfológicos e registro de primeiro aparecimento de táxons, para datar tempo de divergência entre espécies (Smith 1998) e calibrar relógio molecular. A paleontologia também depende de outras ciências tais como a geologia, sistemática e ecologia. Aqui, forneceremos fornecer dados sobre a história da floresta Amazônica durante o Neógeno. Algumas famílias/gêneros serão pela primeira vez descritas no registro fossilífero no Norte da América do Sul. Algumas inferências sobre a paleovegetação serão abordadas, desde famílias predominantes e como esses registros podem ser interpretados. Serão discutidos também alguns aspectos de zoneamentos bioestratigráficos atualmente aceitos e sugerida uma nova interpretação estratigráfica usando-se um método de Bioestratigrafia Quantitativa denominado Associações Unitárias e o compararemos com o zoneamento tradicional utilizado na região

1.2- Registros da “Paleoamazônia”

Acreditava-se que a diversidade biológica da Amazônia estava relacionada à adaptação de espécies a novos ambientes devido a mudanças climáticas ocorridas no Pleistoceno. Atualmente, alguns aspectos dessa teoria denominada “teoria dos refúgios” tem sido testada principalmente por

13 análises moleculares de plantas e animais (Schneider et al. 1999; Aleixo 2004). A maioria desses trabalhos apóia a idéia de que a diversificação da Amazônia ocorreu antes das flutuações climáticas do Pleistoceno e, eventos anteriores a esse intervalo de tempo deveriam ter facilitado a especiação e acumulação de espécies. Eventos ocorridos provavelmente, no Mioceno ou Plioceno (Pennington et al. 2004). No Mioceno, a região Amazônica sofria mudanças ambientais ocasionadas principalmente pelo soerguimento da Cordilheira Oriental Andina, o que propiciou a mudança da direção de drenagem dos rios amazônicos no sentido Atlântico e que, possivelmente, gerou o Rio Amazonas com as mesmas características que as atuais Hoorn et al. 1995. Os Andes também foram responsáveis pela formação do Rio Orinoco na Venezuela além de funcionar como barreira e manter o clima estável na Amazônia pelos últimos milhões de anos (Kaandorp et al. 2005). De forma geral, esses resultados fazem parte de uma ampla pesquisa realizada por holandeses que usaram dados de sedimentologia e paleontologia na Amazônia, Venezuela e Colômbia. Vale ressaltar que a Amazônia sul ocidental brasileira está coberta por rochas terciárias pertencentes à Formação Solimões, que apresenta níveis ricos em conteúdo fossilífero de invertebrados, vertebrados e restos vegetais que afloram principalmente no Estado do Acre. Os fósseis coletados estão atualmente depositados na coleção existente na Universidade Federal do Acre que conta com mais de 5.000 mil exemplares obtidos ao longo dos rios Acre, Purus e Juruá. A maioria das informações extraídas desses fósseis está descrita principalmente, em periódicos nacionais, o que limita o conhecimento e a utilização desses registros em outros estudos internacionais. Esses fósseis, principalmente de vertebrados, são do Mioceno Superior (aproximadamente 9 a 6 milhões de anos passados) e carecem de informações mais detalhadas, tais como: 1) controle estratigráfico dos níveis em que os fósseis foram extraídos; 2) datações absolutas ou zoneamentos bioestratigráficos confiáveis e 3) informações geológicas e paleontológicas

14 integradas que possam permitir um quadro geral sobre a paleoecologia da Amazônia. De acordo com dados paleontológicos, o paleoambiente durante o Neógeno foi complexo, com grandes corpos de água doce. altamente produtivos entre áreas abertas e de floresta densa. Um fato marcante é a grande diversidade encontrada, somente em crocodilianos são 16 espécies registradas, fato que não ocorre atualmente em nenhuma parte do mundo (Cozzuol 2006). Ainda há discussões sobre a diversidade encontrada no Acre ocorrer devido a diferenças temporais ou ambientais (Cozzuol, com. pess). Nesse sentido, a palinologia se faz importante na determinação tanto de fatores estratigráficos como ambientais. O fator estratigráfico pode ser definido, em parte, pela presença de marcadores bioestratigráficos do Neógeno definidos para a região Norte da América do Sul por (Germeraad et al. 1968; Lorente 1986; Muller et al. 1987 e Hoorn 1993) como Crassoretitriletes vanraadshoovenii, Grimsdalea magnaclavata e Echitricolporites spinosus ou, como proposto neste trabalho, por um refinamento do zoneamento mais específico com métodos de Bioestratigrafia quantitativa. O fator ambiental é determinado pela inferência pela caracterização da vegetação dominante que se dá por meio da afinidade botânica e ecológica das espécies observadas em amostras de rochas do Neógeno da Amazônia. Integrados, estes dados podem permitir uma completa interpretação biológica da Amazônia ao longo do tempo.

2.0 Objetivos

2.1 Objetivo geral

A presente pesquisa teve como objetivo principal ampliar o conhecimento dos palinomorfos do Terciário Superior encontrados na Formação Solimões, levando-se em consideração os aspectos sistemáticos, bioestratigráficos e paleoecológicos afim de evidenciar características temporais e ambientais da Amazônia durante o Neógeno.

2.2 Objetivos específicos

1) Descrever grãos novos, seguindo descrições morfológicas empregadas em esporomorfos do Paleoceno e Eoceno da Colômbia a fim de padronizar as descrições feitas em áreas tropicais.

2) Revisar a nomenclatura empregada em esporomorfos já descritos, aplicando-se os conceitos sugeridos pelo Código Internacional de Nomenclatura Botânica.

3) Encontrar padrões no registro palinológico que possam colaborar para uma nova interpretação e uso em bioestratigrafia, contribuindo assim para a criação de um arcabouço cronológico de primeiro aparecimento de espécies que possam ser aplicados bioestratigraficamente em outras áreas na Amazônia.

4) Encontrar padrões na composição palinoflorística durante o Mioceno e Plioceno da Amazônia além de obter dados sobre a origem da diversidade amazônica durante esse intervalo.

3.0- Bacia do Solimões

O Estado do Amazonas possui três grandes Bacias: Bacia do Amazonas, Bacia do Solimões e Bacia do Acre e que, são delimitadas pela presença de arcos estruturais. A Bacia Paleozóica do Solimões possui uma área aproximada de 600.000 km2, entre os paralelos 2º e 8º S e meridianos 62 º e 72º W, limita-se ao leste pelo arco do Purus, que a separa da Bacia do Amazonas, e ao oeste pelo arco de Iquitos, que a separa da bacia do Acre (Silva 1987). Os limites norte e sul são delimitados pelos Escudo das Guianas e Escudo Brasileiro, respectivamente (Figura 1). A localização, extensão e tempo em que o arco de Iquitos esteve exposto têm sido controversa e discutida na literatura (Caputo 1984; Roddaz et al. 2005). A bacia do Solimões possui duas sub-bacias: Juruá e Jandiatuba, sendo as duas separadas pelo arco de Carauari (Figura 2). A sub-bacia de Juruá está localizada ao leste do arco de Carauari e está sendo muito estudada devido a exploração de gás pela Petrobrás desde 1997. A Sub- Bacia Jandiatuba ao contrário da Juruá, é pouco conhecida devido a presença de reservas florestais e terras indígenas (Eiras et al. 1994). No entanto, modelos estruturais do Paleozóico foram desenvolvidos para essa sub-bacia (Silva 1987).

Figura 1: Localização aproximada das Bacias do Estado do Amazonas.

Figura 2: Delimitação das sub-bacias na Bacia do Solimões. Modificado de Silva, 1987

18 A carta estratigráfica da bacia do Solimões adotada pela Petrobrás (Eiras et al. 1994) divide a Bacia do Solimões em nove unidades geológicas desde o Pré-Cambriano: sete delas pertencentes ao Paleozóico, uma ao Mesozóico e a última ao Cenozóico.

3.1- Formação Solimões

A Formação Solimões, unidade geológica que representa o Cenozóico da Bacia do Solimões, está presente também nas bacias do Amazonas e Acre. Pouco consenso existe sobre a sua extensão, ambiente e intervalo de idade dos sedimentos pertencentes a essa unidade (Westaway 2006). O termo Solimões foi designado por Moraes-Rego (1930) que denominou como Série Solimões, as argilas e areias pardas, castanhas e azuis presentes em afloramentos dos rios Acre, Javari, Purus e Solimões (apud RADAMBRASIL 1977). Esse termo foi discutido e revalidado por Caputo et al. (1971). Trabalhos têm tratado a Formação Solimões como correlata de Pebas (Hoorn, 1993; Wesselingh et al. 2001). Essa idéia acabou por se difundir na tentativa de classificação estratigráfica da Fm. Solimões, por exemplo, Almeida (1974) propôs a elevação da Fm. Solimões à categoria de grupo, mantendo a denominação Fm. Pebas para representar uma unidade intermediária do grupo Solimões. Entretanto, Caputo et al. (1971) enfatizam que o termo Pebas somente se refere a algumas camadas fossilíferas aflorantes no Peru e que, esse termo, deveria ser evitado como correlato de Fm. Solimões pois “Pebas” não possui uma descrição formal. Aqui, será utilizada a denominação Formação Solimões por ser uma unidade formalmente descrita. Algumas seções–tipos e de referências distintas (Caputo, et al. 1971; Maia et al. 1977; Eiras et al. 1994) estão descritas para a Formação Solimões e, aqui foram ilustradas duas delas. Caputo et al. (1971), afirmam que a localidade-tipo da Formação Solimões se estende ao longo do Rio Solimões, na Amazônia Ocidental brasileira. A seção de referência corresponde aos primeiros 570 metros de

19 profundidade do poço 2-RCST-1-AM no Rio Curuçá, cuja localização está próxima a fronteira Brasil-Peru (Figura 3). Maia et al. (1977) concorda com a seção-tipo sugerida feita por Caputo et al. (1971) e delimitam geograficamente a seção-tipo entre as cidades de São Paulo de Olivença e Tabatinga, no Estado do Amazonas. A ausência de uma seção-tipo mais específica faz com que Eiras et al. (1994) apresentem um perfil como seção-tipo da unidade, sendo o poço 2- RJ-1-AM (Figura 4) e como seção-referência, o perfil 1-BV-1-AM (Figura 5). O contato inferior da Fm. Solimões com a Formação Alter do Chão é marcado pela redução dos raios gama devido à passagem de argila para areia (como mostrado nos perfis abaixo), e seu contato superior é feito com depósitos de praias e planícies de inundação (Caputo et al. 1971). Em contraposição, Maia et al. (1977) sugerem uma nova unidade denominada Formação Içá para esse depósito. A Fm. Içá composta de arenitos amarelo- avermelhados, fino a conglomerático e friável se sobrepõe a Formação Solimões.

Figura 3: Seção de referência da Fm Solimões. Extraída e modificada de Caputo et al. (1971).

Figura 4: Seção-tipo da Fm. Solimões. Extraído e modificado de Eiras et al. 1994

Figura 5: Seção-referência da Fm. Solimões. Extraída e modificada de Eiras et al. (1994).

23 Ainda de acordo com Caputo et al. (1971), a Formação Solimões consiste litologicamente de: 1) argilitos vermelhos, cinzas e variegadas, sílticos, laminados, com abundantes camadas contendo gipsita em níveis marrons ou cinza-esverdeado; 2) arenitos variando de finos a médios, cinza- esverdeado, branco e marrom-avermelhado, friáveis, com laminação cruzada; 3) conglomerados intraformacionais, com seixos compostos de argilito e siltito e; 4) camadas de linhito de 2 a 10 metros nos primeiros 300 m de profundidade. Em relação à idade em que os sedimentos foram depositados, Caputo et al. (1971) sugerem Paleoceno a Pleistoceno, sendo que trabalhos bioestratigráficos realizados por Daemon e Contreiras (1971) suportavam essa idade. Posteriormente, por meio de associações palinológicas sugeriu idade mais recente (mio/pliocênica) para as seções estudadas. Essa idade proposta por Cruz (1986) foi confirmada dados de vertebrados. A presença de vertebrados fósseis no Estado do Acre permitiu refinar a idade da Formação Solimões no intervalo em que essa unidade aflora, sugerindo o intervalo Mioceno Superior. Latrubesse et al. (1997) registram a presença de roedores: Potamarchus, Neopiblema horridula, Phoberomys burmeisteri e do Toxodonte Trigodon, que indicam idade Mioceno Superior/Plioceno (Huayquerense/Montehermosane). A idade de 9-6.5 Ma poderia ser sugerida baseando-se em SALMA (Huayquerian/Mesopotamian South America land Mammal) com grande similaridade faunística encontrada na Argentina. No entanto, Cozzuol (2006) re-avaliando a idade da fauna do Acre encontrou somente indicativos de Mioceno Superior (Huayquerian South America land Mammal), com a ausência de registros mais recentes.

3.1.1 - Ambientes de deposição

De forma sucinta, Roddaz et al. (2005) sumarizam 5 contraditórias hipóteses que tentam explicar o tipo de ambiente predominante durante a deposição de sedimentos da Formação Solimões. As duas primeiras propõem idade mais recente do que a aceita atualmente na literatura, e são as que afirmam que:

24 1) Os sedimentos foram depositados devido a uma inundação pleistocena vinda do Lago Tititaca (Campbell e Frailey 1984). 2) Eles apresentam uma deposição típica de delta de um grande lago pleistoceno denominado lago Amazonas (Frailey et al. 1988)

As outras três propõem idade miocena e pliocena para a origem da Formação Solimões. 3) Apresentam sedimentos do Mioceno/Plioceno que foram depositados em um sistema de leque aluvial (Latrubesse et al. 1997). 4) São depositados em um sistema fluvial Hoorn 1993) com episódios de incursões marinhas. Nuttall 1990 e Hoorn et al. (1995) sugeriram ainda, que incursões marinhas atingiram o Noroeste da Amazônia brasileira oriundas do Mar Caribenho. 5) Dados sedimentológicos indicam que houve ambientes de maré durante o Mioceno Superior (Rasanen et al. 1995).

E, acrescentando mais uma importante hipótese, não citada no trabalho de Roddaz et al. (2005). 6) A Formação Solimões foi depositada em um sistema de um grande lago que existiu desde o Mioceno Inferior até o início do Mioceno Superior (Wesselingh e Salo 2006). Vonhof et al. (1998) e Wesselingh et al. (2002) baseados em composição de moluscos e isótopos sugeriram que a Amazônia durante o Mioceno Médio Superior apresentava mais características de ambiente lacustre do que de ambiente de planície fluvial e que, portanto, foi coberta por um lago predominantemente de água doce, que atingiu o Norte do Brasil, Colômbia e Peru. Eles sugeriram ainda, que o denominado então “Lago Pebas” teve características semelhantes ao lago de Maracaibo, devido a presença de organismos adaptados à água salobra. Eles acrescentam que, episódios de incursão marinha poderiam ter passado pelos Los Llanos. Dados palinológicos indicam que durante o Mioceno, a Amazônia foi coberta por uma extensa área inundada com abundância de esporos e palmeiras. As bacias do Solimões e Amazonas apresentavam baixa sinuosidade e sistema de drenagem em direção nordeste (Hoorn et al. 1995).

25 A abundância de grãos de Rhizophora (Zonocostites ramonae) e palinomorfos marinhos (dinoflagelados e foraminíferos) sugere incursões marinhas em dois intervalos: uma no Mioceno Inferior (zonas de Verrutricolporites e Psiladiporites-Crototricolpites) e outra no Mioceno Médio/Superior (Zonas de Crasoretitriletes e Grimsdalea) (Hoorn 1994a). Os registros de incursões marinhas foram corroborados por dados moleculares que afirmam que a presença atual de animais descendentes de linhagens marinhas na Amazônia, tais como: peixes, peixes-boi, botos e arraias devem-se a eventos marinhos ocorridos durante o Mioceno Inferior (Lovejoy et al. 1998). No Mioceno Médio/Superior, índices de isótopos de estrôncio confirmam uma incursão marinha na zona de Grimsdalea invadindo um ambiente flúvio-lacustre (Vonhof et al. 1998). Durante esse período, ocorreram mudanças no padrão de drenagem dos rios amazônicos, que passaram a drenar no sentindo atual, com direção de transporte ao Oceano Atlântico. Para o Mioceno Superior existe muita controvérsia em relação a ambiente deposicional e dados palinológicos são escassos para testar os ambientes propostos. Um dos trabalhos mais debatidos é o que propõe um imenso mar intracontinental (hipótese 5) que ligou o caribe com o Atlântico Sul (Rasanen et al. 1995). Esse trabalho descreve que durante o Mioceno Superior, a Amazônia bem como parte do continente sul-americano foi coberto por um mar epicontinental. Essa hipótese foi usada para explicar padrões na distribuição de vegetação na América do Sul (Webb 1995). Apesar dados palinológicos assim como fósseis de vertebrados rejeitarem ambiente marinho/costeiro e apontarem para um ambiente de água doce com pântanos, floresta aberta e com matas de galerias (Cozzuol, 2006; Latrubesse et al. 2007/Anexo2), recentes estudos sedimentológicos também apóiam a presença de marés (Hovikoski et al. 2007). RADAMBRASIL (1977) afirma que todos os afloramentos da Fm. Solimões visitados pelo projeto apontam para um ambiente fluvial com características de ambientes de planícies de inundação (Figura 6).

Figura 6: Modelo de depósito fluvial com fácies de planície de inundação, típicos da Fm Solimões RADAMBRASIL 1977.

3.1.2- Palinoestratigrafia da Formação Solimões

O primeiro arcabouço palinoestratigráfico para o Neógeno desenvolvido em áreas tropicais foi descrito por Germeraad et al. (1968) para África e América do Sul. Esse arcabouço foi posteriormente melhorado Regali et al. 1974; Lorente 1986; Muller et al. 1987) e parcialmente calibrado com o uso de foraminíferos. A aplicação dessas zonas palinoestratigráficas na Amazônia ocorreu poucos anos depois (Daemon e Contreiras, 1971), no entanto, somente na década de 90 foi amplamente divulgada e usada em outros estudos paleontológicos (Hoorn 1993, 1994). No caso do Mioceno e Plioceno, existem poucos e inexatos estudos no que se refere a idade estabelecida a eventos de primeiro aparecimento e extinção de espécies utilizadas bioestratigraficamente, devido a incertezas na correlação com zonas de planctônicos (Germeraad et al. 1968, pg. 247). Somente na década de 90, um trabalho minucioso de bioestratigrafia tradicional foi realizado em dois testemunhos de sondagem perfurados na região do Alto Solimões, permitindo a elaboração de novas biozonas locais usando-se associações Hoorn 1993) que, na prática tem sido usada como marcadores cronoestratigráficos (Wesselingh et al. 2002).

27 Hoorn (1993) estabeleceu para a área, cinco zonas palinológicas do Mioceno Inferior até o intervalo do Mioceno Médio para o Superior. De modo geral, as zonas puderam ser definidas pela presença/ausência e/ou abundância/escassez de espécies (Tabela 1).

Tabela 1: Zonas estabelecidas por Hoorn (1993) com as associações de espécies.

Idade Zonas Associações /limites das zonas Mioceno E: Grimsdalea Topo: indefinido Médio/ Base: primeiro aparecimento de G. Superior magnaclavata D: Crassoretitriletes Topo: antes do primeiro aparecimento de G. Mioceno magnaclavata Médio Base: primeiro aparecimento de C. vanraadshoovenii. C: Psiladiporites- Topo: antes do primeiro aparecimento de Crototricolpites C.vanraadshoovenii. Base: Primeiro aparecimento de P. minimus, C. annemariae, Proxapertites tertiaria ou Mioceno Retimonocolpites absyae. Inferior B: Retitricolporites Topo: Abundância de R. guianensis Base: : decréscimo de V. rotundiporus A: Verrutricolporites Topo: decréscimo de V. rotundiporus Base: Abundância de V. rotundiporus

De acordo com Hoorn (1993) as zonas acima descritas foram modificadas a partir de zonas estabelecidas anteriormente por Lorente (1986) na Venezuela. As idades das zonas palinológicas definidas para a três Bacias na Venezuela foram calibradas usando-se dados de foraminíferos e nanofósseis calcáreos (Lorente 1986). No entanto, algumas espécies utilizadas como marcadores bioestratigráficos necessitam ser revisadas pelo fato do ambiente estar controlando sua a presença. Por outro lado, alguns marcadores usados nessa abordagem têm seu primeiro aparecimento mais antigo do que se afirmava. Leite (2007) registrou zonas mais recentes do que as proposta por Hoorn (1993). Em suas amostras da sondagem 1AS-33-AM foi registrada a presença de Psilatricolporites caribbiensis marcando portanto, rochas pliocenas na área.

4.0 Material e Métodos

4.1 Área de estudo Na década de 70 dois grandes projetos foram financiados pelo governo federal na região do Alto Solimões e executados pela CPRM e DNPM, favorecendo assim, o conhecimento geral do ambiente amazônico que até então, havia sido estudado por pequenos grupos de pesquisa atuando em áreas pontuais. O primeiro projeto denominado “Projeto carvão do Alto Solimões” tinha como finalidade explorar áreas com potencial para produção e exploração de carvão. Com esse projeto foi possível a perfuração de alguns poços de sondagem cobrindo uma extensa área no Alto Solimões, atingindo a Fm. Solimões, Fm. Içá e Fm. Alter do chão. Esses testemunhos de sondagens estão atualmente depositados na litoteca do DNPM-Manaus. Simultaneamente, foi desenvolvido o segundo projeto denominado como RADAMBRASIL- Programa de integração Nacional, que tinha como objetivo o levantamento de recursos naturais na região. Nesse projeto foram realizados levantamentos sobre geologia, geomorfologia, pedologia e inventários florísticos em toda Amazônia. Informações e material de sondagem desses dois projetos foram utilizados para a elaboração dessa tese. Dois poços, 1AS-27-AM (folha SB 19 XA) e 1AS-19-AM (folha SB 19 VB) foram escolhidos (figura 7), levando-se em consideração dois fatores: posição mais central dentro da Bacia e estado de conservação desse material na litoteca. Na folha SB 19 Juruá, onde os poços estão localizados, a Formação Solimões apresenta duas formas de relevo, o planalto rebaixado da Amazônia e depressão do Rio Acre-Javari. De acordo com o RADAMBRASIL (1977), essa área é composta por contrastes morfológicos e texturais em que os relevos podem estar associados com tipos da litologia da Fm Solimões: 1) relevo colinoso mais baixo associados com sedimentos síltico-argiloso de

29 depósitos de transbordamento; e 2) relevo colinoso mais elevado associados com depósitos arenosos típicos de barras em pontal. Esses dois ambientes estão relacionados com ciclos fluviais.

Figura 7: Mapa de localização onde os poços foram perfurados.

4.1.1- Poço 1AS-27-AM De acordo com o RADAMBRASIL (1977), a área em que a sondagem foi realizada é caracterizada geologicamente por arenitos terciários que se apresentam em forma de: 1) interflúvios tabulares, 2) relevos dissecados (cristas ou colinas) e 3) superfície ondulada e faixas com áreas de acumulação de sedimentos recentes próximo aos rios (terraços, áreas inundadas e inundáveis). A área de sedimentos terciários é dominada por vegetação de Floresta Densa com dominância de árvores com porte de 30-40 m e por florestas de palmeiras. Em terrenos Quaternários, a Floresta densa somente

30 domina os terraços sendo que nas planícies inundáveis e inundadas há dominância de palmeiras. O poço 1AS-27-AM, com coordenadas de 04°17’S e 67°5’W, tem 402,5 metros de profundidade, localizado próximo a Tamanduá, no Rio Jutaí. De acordo com o perfil estratigráfico, ele atinge três Formações geológicas: Içá, Solimões e Ramon. O perfil litológico e geofísico dessa sondagem com a localização das amostras encontra-se na figura 8.

Figura 8: Perfil estratigráfico do poço 1AS-27-AM juntamente com perfis de raios-gama e resistividade.

4.1.2- Poço 1AS-19-AM Atualmente, a área em que o poço 1AS-19-AM foi perfurado é coberta principalmente por arenitos terciários (interflúvios tabulares, relevos dissecados em cristas e colinas e superfície ondulada) seguido de depósitos Quaternários (terraços e planícies aluviais)(Figura 7). O inventário florístico feito pelo RADAMBRASIL (1977)- folha SB 19 VB, mostra que a área é dominada por florestas de palmeiras que se estendem sobre áreas de depósitos Quaternários e Terciários seguida de áreas com florestas emergentes. O poço 1AS-19-AM (04°33’S/69°10’W) é mais raso que o 1AS-27-AM tendo somente 255,7 metros de profundidade. Essa sondagem foi feita próximo ao igarapé Boa vista e Rio Jandiatuba, no Município de São Paulo de Olivença, Amazonas. No perfil estratigráfico realizado pela CPRM está descrito que toda a seção pertence ao Terciário e somente os 3 primeiros metros de areia pertencem ao Holoceno. Como pode se observar abaixo, toda a seqüência está composta de argila intercalada com níveis de areias. No intervalo de 100 a 220 metros de profundidade estão descritos alguns níveis fossilíferos, calcíferos e carbonosos, com material orgânico bem preservado (Figura 9).

Figura 9: Perfil estratigráfico do poço 1AS-19-AM juntamente com perfis de raios-gama e resistividade.

4.2 Preparação das amostras e contagem dos grãos

No total 41 amostras foram estudadas nos dois poços. Essas amostras foram preparadas no Instituto Colombiano del Petroleo-ICP seguindo a metodologia descrita em Traverse (1988) e detalhadamente descrita em vários trabalhos (Antonioli 2001; Leite 2007). As amostras foram selecionadas de acordo com a cor do sedimento (materiais mais escuros são mais promissores) e de granulometria média (material argiloso) (Antonioli 2001). A metodologia consiste no ataque com ácido clorídrico e fluorídrico de modo que não restem mais resíduos de materiais inorgânicos como: carbonatos, silicatos e matéria orgânica carbonizada. Em linhas gerais o tratamento empregado foi:

1) Maceração das amostras, ataque com HCl a 32% por 2 horas para eliminação de carbonatos.

2) ataque com HF a 40% por 18 horas para eliminação de silicatos, para retirada do produto resultante (fluorsilicato) utilizou-se HCl a 10%.

3) O material foi lavado, em todas as etapas, com água destilada por três vezes para neutralizar a ação dos ácidos.

4) Após a acidificação das amostras, peneirou-se em malha de 200µm visando-se eliminar a parte inorgânica grosseira e assim concentrar os palinomorfos na fração restante.

5) Nos casos de amostras com material orgânico carbonizado utilizou- se uma solução composta por HNO3 e KCLO3 de 15 min. a 1 hora dependendo do grau de oxidação da amostra. O tempo de duração é determinado pela mudança da cor de preto para castanho (Antonioli 1998). A solução usada para oxidar parte da matéria orgânica foi utilizada em uma parte de cada amostra, sendo também utilizada essa fração para a contagem dos grãos. Estruturas morfológicas dos grãos são mais facilmente

34 distinguíveis quando as amostras são oxidadas. Entretanto, grãos com exina muito sensível podem ser perdidos durante essa etapa do processo químico. Por isso, preferiu-se usar duas lamínulas na mesma lâmina, uma com material oxidado e a outra com material não oxidado.

6) Após a lavagem com HCl a 10% e lavagem com água destilada preparando a amostra para a separação de constituintes pela diferença da densidade entre eles. Esse método consiste na separação por flotação utilizando ZnCL2 de densidade entre 1,95 a 2,0 que é então, centrifugado por 20 minutos em velocidade de 1500 a 2000 rpm. A parte sobrenadante é retirada e novamente submetida a centrifugação com Cloreto de zinco por 20 min. a 1500-2000 rpm.

7) O material sobrenadante é colocado em outro tubo com álcool comercial e centrifugado por 5 min. a 1500-2000 rpm. O resíduo foi lavado com água destilada por 1 min. e em seguida centrifugado com HCl a 10% por 1 min. em velocidade de 1500-2000 rpm.

8) Finalmente, as amostras foram lavadas por três vezes com água destilada. No entanto, havendo permanecido material húmico nas amostras . Esta foi aquecida por 15 min. com KOH. Após essas etapas o resíduo foi então peneirado com malha de 10 µm e a fração retida na peneira foi transferida para tubos de 10 ml para a preparação de lâminas palinológicas.

9) Uma lâmina de cada amostra foi confeccionada e analisada em Microscópio Zeiss, Eclipse 200 em objetivas de 20x e 100x. Quando possível, 300 grãos de pólen e esporos foram contados em cada lâmina, além de esporos de fungos e algas.

4.3 Análise dos dados

4.3.1- Sistemática, taxonomia, afinidades botânica e ecológicas dos esporomorfos.

Os trabalhos de Van der Hammen (1956a) foram pioneiros na Palinologia tropical. Entretanto, alguns gêneros fósseis propostos nesses

35 trabalhos possuem espécies recentes como espécie-tipo, o que vai de encontro com as normas do Código Internacional de Nomenclatura Botânica- ICBN (sigla em inglês), o que os tornam gêneros inválidos. Esses gêneros foram revisados e substituídos por gêneros válidos fazendo-se novas combinações, conforme sugestões (Jansonius e Hills 1976; Jansonius 1978; Burger 1994). Na a revisão realizada nesse trabalho,foram utilizadas as descrições genéricas feitas em Jansonius e Hills (1976) e suplementos. Novas espécies foram detalhadamente descritas, utilizando-se a nomenclatura de morfologia polínica sugerida em Punt et al. (2007) e foi seguido como modelo as descrições de Jaramillo e Dilcher (2001). Para esporos um índice (TLI-para triletes e MLI-para monoletes) foi usado para indicar a relativa proporção do radius x comprimento do grão, para esporos triletes: TLI (index trilete) = comprimento do radius/ (diâmetro do esporo/2) e para monoletes: MLI (index monolete) = comprimento da laesura/ comprimento do esporo.

Na descrição do pólen, dois índices foram usados CPi e CPe para indicar a proporção do colpi X dimensões do grão. Pólen em vista equatorial:

Cpi (comprimento do colpi/diâmetro polar) e pólen em vista polar: CPe (comprimento do colpi/ diâmetro equatorial).

No mínimo duas medidas foram tiradas para expressar a dimensões dos grãos. Os tamanhos extremos (máximo e mínimo) e a média de tamanho entre parênteses, o desvio padrão, as proporções de diâmetro polar x diâmetro equatorial e o número de grãos que foram medidos (n). O comprimento do diâmetro equatorial e largura foram medidas em vista equatorial dos grãos. Os diâmetros polar e equatorial foram medidos em vista polar. Para a correta identificação dos grãos de pólen e esporos e comparações, vários holótipos descritos (Regali et al. 1974, Lorente 1986, Hoorn 1993, Hoorn 1994b e Jaramillo e Dilcher 2001) foram detalhadamente analisados.

36 As afinidades botânicas dos grãos foram estabelecidas e comparadas com grãos atuais usando-se tanto a literatura especializada (Absy, 1979; Hooghiemstra 1984; Roubik e Moreno 1991) como a coleção de palinologia do INPA e coleção do Amazonas do STRI. Informações botânicas como: hábitos, estratégia reprodutiva das famílias e gêneros além de dados interpretação ambiental dessas famílias foram obtidas em (Absy 1979; Poumot 1989, Bush 1995Ribeiro et al. 1999).

4.3.2- Bioestratigrafia

No presente estudo, foram utilizadas duas formas de se analisar dados bioestratigráficos: 1) A bioestratigrafia tradicional, que leva em consideração, a presença/ausência ou abundância de marcadores bioestratigráficos para determinar idade aos sedimentos. A interpretação dos dados foi feita de acordo com o zoneamento estabelecido para o norte da América do Sul (Germeraad et al. 1968; Regali et al. 1974; Lorente, 1986; Muller et al. 1987; Hoorn, 1993). 2) A bioestratigrafia quantitativa, sendo escolhido o método de Associações Unitárias (Unitary association- UA) devido à natureza das seções disponíveis para esse estudo. O método de associações unitárias foi desenvolvido por Guex (1991) para a correlação bioestratigráfica de afloramentos pertencentes a diferentes localidades. Esse método utiliza matrizes e conceitos em teoria de gráficos para estabelecer relações de co- existência e superposição entre as espécies. Desse modo, o método constrói uma escala cronológica de eventos, descrevendo uma seqüência de intervalos usando-se associações denominadas UA. Com a utilização desse método será possível estabelecer novas zonas com novas associações de espécies além de permitir a correlação entre os dois poços. Para essa análise, 41 espécies foram selecionadas (tabela 3) conforme sugestões feitas por Guex (1991), tais como: eliminar espécies endêmicas, ou seja presentes em somente uma seção; eliminar espécies que

37 co-existem com todas as outras ou seja, espécies com ampla distribuição temporal foram retiradas da análise para se evitar erro na correlação. O método das associações unitárias trará zoneamentos alternativos aos depósitos da Fm. Solimões, pois acredita-se que os zoneamentos estabelecidos para esta região têm sido feitos em seções cujos intervalos são pequenos e não seções completas como têm sido interpretadas. Essa premissa, da qual parte esse trabalho, se deve ao fato de que, quando comparamos ao Mioceno de outras regiões (Urumaco na Venezuela com cerca de 9 km), encontramos seções com apenas 300 metros de espessura na Amazônia interpretadas como abrangendo quase todo o Mioceno Hoorn 1993. Sendo que, esse intervalo recobre menos de 30% do valor mínimo descrito para a espessura da Fm. Solimões (Caputo et al. 1971).

5.0 Resultados e discussões

5.1 Sistemática

Menos de 10 trabalhos palinológicos do Mioceno e Plioceno do norte da América do Sul foram realizados desde a década de 60 (Germeraad et al. 1968, Regali et al. 1974, Lorente 1986, Muller et al. 1987 Hoorn 1993). Desde então, todos os grãos e esporos foram descritos utilizando-se a mesma nomenclatura genérica proposta e empregada em Van der Hammen 1956b. Jansonius e Hills (1976) afirmam que os gêneros descritos principalmente nos trabalhos de Van der Hammen são gêneros inválidos devido à utilização de grãos atuais como espécies-tipo para suportar a descrição do gênero fóssil. Gêneros com nomenclatura artificial amplamente utilizada em palinologia, tais como: Psilatricolporites, Retitricolporites e Fenestrites, necessitam ser revisados e trocados por nomes genéricos válidos. Por outro lado, nomes de gênero que usam caracteres morfológicos deveriam ser evitados (artigo 20.2), de acordo com o Código Internacional de Nomenclatura Botânica (Código de Saint Louis, 2000), Nesse trabalho, foram detalhadamente descritos e revisados no total 112 esporomorfos. Desses, 51 são esporomorfos descritos pela primeira vez na literatura. Sete novas combinações, aplicando-se gêneros válidos, foram propostas como sugerida pelo Código. Essa revisão resultou em um detalhado trabalho taxonômico e sistemático que está sendo revisado com as morfoespécies encontradas nos poços 1AS-19-AM e 1AS-27-AM e que será brevemente submetido. No anexo 1 encontra-se o manuscrito (em fase de revisão) que será submetido a Paleontographica B, nível B internacional (segundo Qualis-CAPES).

5.2- Bioestratigrafia

5.2.1- Bioestratigrafia tradicional

De acordo com a bioestratigrafia tradicional as seções aqui estudadas são interpretadas e correlacionadas da seguinte maneira:

1) 1AS-27-AM: esta sondagem possui duas biozonas: 1) intervalo mais inferior, (354.5 m a 221 m): Zona de Asteraceae- subzona de Fenestrites- descritas por Lorente (1986) como características do Mioceno Superior; 2) intervalo superior (221 m até 43 m): zona de Psilatricolporites caribbiensis que pertence ao Plioceno. Na amostra mais antiga (400 m) não foi observada a presença de nenhum importante marcador, aqui o incluiremos no intervalo da Zona de Asteraceae. Em todo o intervalo estudado, houve presença de Grimdalea magnaclavata e Crassoretitriletes vanraadshoovenii.

2) 1AS-19-AM: toda a seção estudada de 218 m pertenceria à zona de Psilatricolporites caribbiensis, devido a presença do marcador estratigráfico que tem o mesmo nome da zona. Esta seção seria correlacionada com a parte superior da sondagem anteriormente descrita. A correlação entre poços encontra-se na figura 10.

Figura 10: Correlação estratigráfica usando a bioestratigrafia tradicional da região.

Levando-se em consideração a presença dos marcadores bioestratigráficos, essas duas seções são mais recentes do que o poço 1AS- 4a-AM estudado por Hoorn (1993) e são contemporâneas com o poço 1AS- 33-AM de Leite (2007). De acordo com a bioestratigrafia tradicional, as associações encontradas em seções do Mioceno Superior/Plioceno são compostas de três importantes grãos: Fenestrites spinosus, Pachydermites diederixii (Symphonia) e Stephanocolpites evansii (Rubiaceae, Borreria?). No entanto, nenhum desses três marcadores foi observado em nossas duas seções. Lorente (1986) reporta que Pachydermites diederixii somente é encontrado em uma das três Bacias por ela estudada, a Bacia da Oriental da Venezuela, sendo completamente ausente das Bacias de Falcon e

41 Maracaibo. O mesmo ocorre em sedimentos do Quaternário, observando-se diagramas polínicos da Amazônia Absy 1979, Symphonia está apenas registrada em duas (lago cuminã e Costa da Terra Nova-IA) das seis seções analisadas. Nessas localidades, a freqüência do grão de Symphonia apresenta baixa percentagem, com menos de 5% de toda associação polínica sendo, portanto, considerado raro. A ausência de Pachydermites diederixii provavelmente possa estar relacionada à especificidade de habitat da planta ou baixa incidência populacional no Mio/Plioceno da Amazônia. Germeraad et al. 1968) sugerem que Symphonia globulifera ocorre em áreas de pântanos costeiras na África e América do Sul, mas Ribeiro et al. (1999) descreve que atualmente Symphonia globulifera está presente na floresta de terra firme na Reserva Ducke, Amazônia Central com ampla distribuição e freqüência. No caso do o grão de Stephanocolpites evansii, Lorente (1986), coloca o seu primeiro aparecimento na zona NN11 de nanoplâncton e na zona de foraminíferos planctônicos Globorotalia dutertrei e Globorotalia acostaensis (Tortoniano/Mioceno Superior). Muller et al. (1987) registra o primeiro aparecimento de Stephanocolpites evansii no Plioceno. Hoorn (1994) também registra a presença de Stephanocolpites evansii em seções da Colômbia e Peru de Três Islãs III, Mariname III, Santa Sofia, Mocagua, Los chorros I E e Pijuayal. A ausência de marcadores “raros” na associação faz com que sejam estabelecidas idades errôneas a algumas seções como provavelmente, foi publicado por Hoorn (1994) que ignora a presença de um marcador do Mioceno Superior/Plioceno (Stephanocolpites evansii) devido a ausência de outras espécies do Mioceno Superior. Apesar dessa importante interpretação, e como enfatizado em Latrubesse et al. (2007), novas seções necessitam ser estudadas e um novo zoneamento feito para avaliar essas inconsistências antes de se inferir idade para sedimentos. As biozonas estabelecidas para o Mioceno e Plioceno estão baseadas na ocorrência de poucas espécies marcadoras de idade ou espécies que aparecem em baixa freqüência no registro fossilífero. McGowran (2005) afirma que os bons marcadores bioestratigráficos apresentam duas características: abundância no registro e ampla dispersão

42 geográfica. Fato não observado em seções do Mioceno Superior e Plioceno. Uma outra característica fundamental na procura por espécies-guia é o fácil e exato reconhecimento morfológico do grão. Na tabela 2 está descrito o zoneamento elaborado para a Venezuela e usado na Amazônia.

Tabela 2: Zonas palinológicas estabelecidas para Venezuela e Amazônia.

As espécies-guias usadas para marcar o Mioceno Inferior (tabela 1) possuem grande controle ambiental como no caso de V. rotundiporus. As outras possuem baixo potencial de fossilização (Psiladiporites minimus, Echitricolporites maristellae). Psiladiporites minimus tem afinidade botânica com Fícus (Moraceae), que de acordo com Bush (1995) é raramente fossilizado devido à baixa produção de pólen e sua especificidade com o polinizador. No caso de Echitricolporites maristellae, normalmente sua presença é marcada sempre pela baixa freqüência na associação. O oposto acontece no Mioceno Médio e Médio/Superior, pois existem dois excelentes marcadores que caracterizam esse intervalo (Crassoretitriletes vanraadshoovenii e Grimsdalea magnaclavata). Eles são bons marcadores devido à alta freqüência observada tanto nos seus primeiros aparecimentos quanto em todo o intervalo de sua existência. Quanto à extinção desses marcadores, somente Grimsdalea se torna extinto provavelmente, no início do Pleistoceno (Lorente 1986). Em relação ao Mioceno Superior e Plioceno, o grande problema é que os grãos utilizados apresentam sempre baixa freqüência nas associações (e.g. Fenestrites spinosus e Fenestrites longispinosus (Asteraceae), Psilatricolporites caribbiensis, Stephanocolpites evansii (Borreria?), Pachydermites diederixii (Symphonia) e Echitricolporites mcneilly (Ambrosia- Asteraceae). Em parte isso se deve a síndrome de polinização que em áreas tropicais que tendem a ser especificas e com baixa produção polínica quando comparadas a aquelas anemófilas (Bush 1995). Por isso, há necessidade em encontrar outras espécies mais eficientes que possam ser utilizadas como marcadores do Mioceno Superior e Plioceno na Amazônia. No anexo 2 está um trabalho publicado que trata sobre os erros de interpretação cometidos na literatura usando-se os elementos palinoestratigráficos atuais. Como pode ser observado nas cartas de distribuição dos poços 1AS- 27-AM (Fig. 13) e 1AS-19-AM (Fig. 14), a freqüência dos marcadores: Fenestrites longispinosus (Cichoreacidites longispinosus) e Psilatricolporites

45 caribbiensis (Horniella? caribbiensis) é sempre menor que 3% da associação (Figuras 11 e 12). Outro problema observado foi o primeiro registro de Clavainaperturites microclavatus (Hedyosmum) em seções da Colômbia e Peru. Hoorn (1994) interpreta seu primeiro registro no Mioceno Médio. Entretanto, nesse mesmo trabalho, Clavainaperturites microclavatus está associado a Stephanocolpites evansii em muitas seções tais como, Santa Sofia, Mocagua, Los chorros I E, Pijuayal, o que indica idade mais recente para essas localidades. Van der Hammen et al. (1973) registra o primeiro aparecimento de Hedyosmum nos Andes colombianos ocorrendo no Plioceno Inferior. Entretanto, o primeiro aparecimento de Hedyosmum ainda permanece em discussão, pois em seções estudadas na Colômbia pelo Instituto Colombiano del Petróleo esta espécie aparece desde o Mioceno Médio (Rueda,com. pess.). A. Antonelli (com. pess.) afirma que o primeiro clado de Hedyosmum começa a radiar a 11.2 Ma. Diante do exposto, e baseando-se nas zonas estabelecidas para o Mio/Plioceno, as presenças de Fenestrites longispinosus e Psilatricolporites caribbiensis indicam, de acordo com a bioestratigrafia tradicional, que as seções são mio/pliocenicas, sendo esse, juntamente com o poço 1AS-33-AM Leite 2007, os primeiros registros de seções dessa idade na Amazônia. Certa precaução será tomada em referir-se ao Plioceno, pois novos métodos de bioestratigrafia quantitativa deverão ser aplicados além de novas localidades amostradas para se poder afirmar essa idade para seções da Fm. Solimões no Estado do Amazonas.

Figura 11: Carta de distribuição do 1AS-27-AM

Figura 12: Carta de distribuição do 1AS-19-AM.

5.2.2- Bioestratigrafia quantitativa

Devido aos fatores mencionados no tópico de Bioestratigrafia tradicional, foi optado pelo o uso de métodos quantitativos para evitar erro na interpretação de dados devido a ausência de marcadores ocasionada pela baixa freqüência no registro polínico. De acordo com o método de Associação unitária, e confirmando a interpretação dada anteriormente, as duas seções foram correlacionadas e são contemporâneas (Figura 13), permitindo assim que algumas biozonas sejam estabelecidas.

Figura 13: Correlações estratigráficas usando-se o método de Associação Unitária

49 A Associação Unitária apresentou em 2 AU’s resultantes de 5 cliques maximal (maximal cliques) e 12 máximos residuais. Somente 2 contradições foram encontradas. Os cliques maximal foram encontrados nos intervalos: seção 27- 161,2m, 27- 280,2m, 19-143m, 19-4,5m e 19- 218m. Isso significa que nessas seções/amostras foram encontrados o número máximo de espécies co-ocorrendo do que em qualquer outro intervalo. Já que o método trabalha com zonas de amplitude (Concurrent zone), é a partir desses cliques maximal que as AU são sugeridas. As figuras 14 a e b ilustram os gráficos de co-ocorrência (a) e superposição (b) entre as espécies. Observa-se que todas as espécies correlacionam entre si, isso significa dizer que as espécies têm uma ampla distribuição geográfica e temporal, tornando-se difícil a correlação entre localidades por separação em zonas. No entanto, o gráfico de superposição mostra que a espécie 20 (Margocolporites muelleri) tem superposição com 8 espécies, sendo esta uma importante característica para a escolha do bom marcador. Os números dos vértices correspondem às espécies (tabela 3). O método permitiu o estabelecimento de duas zonas, aqui chamadas de AU 1 e AU 2.

12 11 10 12 11 13 13 10 9 9 14 14 8 8 15 15 7 7 16 16 6 6 17 17 5 5 18 18 4 4 19 19 3 3 20 20 2 2 21 21 1 1 22 22 41 41 23 23 40 40 24 24 39 25 39 38 25 26 38 37 26 27 37 36 27 28 36 35 28 29 35 30 34 31 33 29 32 30 34 31 32 33

A B

Figura 14: A) gráfico não Orientado, onde os números correspondem as espécies (vértices) e as setas em azul (arestas) correspondem a relação de co -ocorrência entre as espécies, B) gráfico Orientado, onde os números correspondem as espécies (vértices) e as setas em vermelho (arcos) correspondem a relação de superposição entre as espécies.

A UA 1 é composta de 80% da associação polínica e a presença de Margocolporites muelleri n. sp. está restrito a essa zona. A UA 2 tem 8 espécies presentes nessa zona (tabela 3). A tabela 3 mostra a composição de espécies usada para construir cada UA e as zonas de intervalo sugeridas. No total 8 espécies, sendo que a maioria delas é novas espécies, apresentam-se como bons marcadores bioestratigráficos locais: Bombacacidites fossulatus, Clavainaperturites microclavatus, Margocolporites muellerae, Retitrescolpites sp. 2, Retitriletes murielevatus, Siltaria sp.1, Striasyncolporites anastomosus e Echiperiporites estelae. Entretanto, esses marcadores também apresentaram baixa freqüência polínica na associação.

Tabela 3: Tabela mostrando a composição de cada UA. Em amarelo está a associação típica da UA2. Em azul a espécie encontrada somente na UA1. Na seção intermediária estão as espécies das UA1/2. A primeira coluna corresponde aos números contidos nos gráficos orientados e não orientados.

2 Bombacacidites fossulatus 5 Clavainaperturites microclavatus 9 Echiperiporites estelae 29 Retistephanocolporites sp1 32 Retitriletes murielevatus 31 Retitrescolpites sp2 35 Siltaria sp1 37 Striasyncolporites anastomosus

1 Arecipites perfectus 3 Bombacacidites nacimentoensis 4 Bombacacidites zuatensis 6 Crassiectoapertites colombianus

51 7 Ctenolophonidites suigeneris 8 Echinatisporis muelleri 10 Echiperiporites intectatus 11 Foveotricolporites pseudodubiosus 12 Heterocolpites incomptus 13 Heterocolpites rotundus 14 Heterocolpites verrucosus 15 Horniella caribbiensis 16 Horniella morenae 17 Hydrosporis minor 18 Kuylisporites waterbolkii 19 Ladakhipollenites floratus 21 Margocolporites pseudodemicolpatus 22 Margocolporites vanwijhei 23 Parsonsidites brennacII 24 Podocarpites sp 25 Polypodiisporites planus 26 Proteacidites triangulatus 27 Proxapertites tertiaria 28 Psilastephanoporites herngreenii 30 Retistephanoporites crassiannulatus 33 Rhoipites gigantiporus 34 Rhoipites guianensis 36 Siltaria tectus 38 Striatricolporites digitatus 39 Striatricolporites poloreticulatus 40 Tetracolporopollenites sp1 41 Tricolpites sp

20 Margocolporites muellerae

O poço 1AS-27-AM mostrou associação presente nas duas UA’s e funcionou como modelo para comparar com o 1AS-19-AM. Como dito anteriormente, de acordo com UA, as seções são contemporâneas e a correlação entre poços sugerida. O uso das espécies com potencial estratigráfico aqui sugerido e mostrado na tabela 3 servirá para avaliar sua aplicabilidade em outras seções e Bacias.

5.3- Paleoecologia

A paleoecologia contribui para a compreensão da biodiversidade em uma ampla escala de tempo e área geográfica (Odgaard 1999). De acordo com Morley (2000) os registros de grãos de pólen e esporos evidenciam padrões da vegetação em escala regional devido a sua ampla dispersão, produção e facilidade em fossilizar em vários ambientes de deposição. Entretanto, essas evidências deveriam ser interpretadas com precaução devido a problemas tafonômicos, que poderiam interferir na qualidade do registro fossilífero. Alguns indicadores paleopalinológicos de florestas tropicais poderiam ser a identificação de famílias tropicais tais como: Annonaceae, Combretaceae, Malvaceae (Dilleniaceae, Bombacaceae) e Guttiferae, além de mudanças na abundância polínica de determinados tipos de vegetação (Morley 2000). Nesse estudo foi registrada a presença de muitas famílias denominadas tropicais, tais quais: Bombacaceae e Annonaceae indicando condições tropicais similares as atuais com uma floresta bem estruturada. No entanto, nossos resultados mostraram abundância de esporos, gramíneas e palmeiras, fato relacionado a alta produção e facilidade de dispersão desses esporomorfos.

5.3.1- Relação abundância e raridade na composição palinológica

Observou-se na composição palinoflorística abundância de esporos nas associações dos dois intervalos estudados (Figura 15 e 16), com mais de 50% do total da associação encontradas nos dois poços.

Figura 15: Gráfico de freqüência (%) de esporos, famílias de angiospermas e gimnospermas encontradas no Poço 1AS-27-AM.

Figura 16: Gráfico de freqüência de esporos, famílias de angiospermas e gimnospermas encontradas no Poço 1AS-19-AM.

Esses resultados corroboram com os trabalhos de Hoorn (1993), Rull (2001) e Leite (2007) que registram abundâncias de Laevigatosporites tibuensis e Polipodiisporites usmensis em seções do Mioceno Inferior até o Mioceno Superior/Plioceno. Este fato pode ser explicado pela alta resistência de esporos ao transporte a longas distâncias e a alterações ambientais

54 (Poumot 1989; Playford e Dettman 1996). Por outro lado, a necessidade por localidades mais úmidas para dispersão de esporos, poderia estar favorecendo a representação desses em nossa análise palinológica. Em ambientes costeiros, a abundância em esporos indicaria uma baixa no nível do oceano. Durante este intervalo, a atividade fluvial se torna mais ativa, transportando mais esporos, que devido a sua melhor resistência, se fossilizam com mais facilidade (Poumot 1989). Os esporos triletes (Crassoretitriletes vanraadshoovenii, Deltoidosporis adriennis) e os monoletes (Laevigatosporites tibuensis e Polypodiisporites usmensis) indicam a presença de ambiente com alta umidade e com árvores, pois a maioria das pteridófitas encontradas na associação polínica possui afinidade botânica atual com espécies com hábitos de lianas, epífitas ou hemi-epífitas, como mostrado na tabela 4.

Tabela 4: Afinidade botânica e hábito de alguns esporos que apresentaram abundância na associação.

Nome Fóssil Afinidade Hábito Referência botânica Echitriletes muelleri Selaginella Ervas Ribeiro et al. 1999 Crassoretitriletes Lygodium Lianas/hemiepífitas Ribeiro et al. 1999 vanraadshoovenii Magnastriatites Ceratopteris Ervas aquáticas Frederiksen 1985 grandiosus Polypodiaesporites Pteris Porte arbóreo Ribeiro et al. 1999 gemmatus Polipodiisporites Polypodium Epífitas Ribeiro et al. 1999 usmensis Laevigatosporites Lianas Frederiksen 1985

Além de esporos, houve também predominância de grãos de Poaceae e Arecaceae nas duas seções estudadas. Isso se deve a síndrome de polinização dessas plantas que por dispersarem os grãos pelo vento necessitam de alta produtividade polínica. Bush (1995) afirma que apesar de as plantas anemófilas serem raras em florestas tropicais (2.5% de todas as árvores), elas são bem representadas no espectro polínico (27%).

55 Essa facilidade em dispersão pode se explicar o padrão encontrado em sedimentos do Mioceno/Plioceno. O autor acima citado também, afirma que plantas presentes na proximidade de lagos ou pântanos têm maior chance em aparecer no registro em relação a aquelas de floresta de terra firme. A presença de gramíneas poderia estar indicando dois tipos de ambientes distintos: 1) de vegetação aberta tipo savana ou cerrado e, 2) ambientes próximos a rios ou lagos e que, se acumulam em forma de “floating meadows” (Absy 1979). Estudos do Pleistoceno utilizam a alta freqüência de gramíneas no registro polínico para inferir a presença de áreas abertas na Amazônia (Van der Hammen 1972) e suportar a idéia de refúgios, porém essa interpretação tem sido avaliada (Absy 1979). A expansão de gramíneas no Mioceno Superior poderia também estar relacionada com o grande aporte de sedimentos ricos em nutrientes vindos dos Andes Hoorn 1993 e co-evolução com animais pastadores (grazers) como peixes-boi (Retallack 2001). Em relação às palmeiras, a maioria delas indica áreas de pântanos Absy 1979. Esses dois elementos, somado a abundância de esporos, indicam áreas aquáticas/pantanosas nas proximidades das áreas amostradas. A tabela 5 representa as estratégias reprodutivas, mecanismos de polinização e hábitos das plantas que tem seus grãos de pólen representados nesse estudo. Informações retiradas de Bush (1995) e Morley (2000).

Tabela 5: Tabela com alguns tipos polínicos encontrados e suas informações botânicas. Tipos de pólen Estrutura Polinizadores reprod. Alchornea Dióica Vento Poaceae Monóica Vento Mauritia Dióica Insetos generalistas Euphorbiaceae Mon/dio Ins. gen/abelhas Tubuliflorae Hermafrodita Ins. gen./borboletas Arecaceae Mono/dio Insetos generalistas Ilex Dio/Herm Insetos generalistas Cróton Monóica Insetos generalistas Loranthaceae Herm/mon Insetos generalistas

56 Malpighiaceae Hermafrodita Abelhas Malvaceae Herm/Dio Abelhas Polygonum Hermafrodita Abelhas Rubiaceae Hermafrodita Abelhas Sapium Monóica Insetos generalistas Amanoa Monóica Insetos generalistas Apocynaceae Hermafrodita Abelhas Caryophyllaceae Hermafrodita Abelhas Ludwigia Hermafrodita Abelhas Pachira Hermafrodita Morcegos Podocarpus Monóica Vento Byttneria Hermafrodita Abelhas Gomphrena Hermafrodita Abelhas Humiria Hermafrodita Abelhas

Dois padrões são bem distinguíveis em análises palinológicas de sedimentos da Amazônia: poucas espécies muito abundantes e muitas espécies raras. Essa mesma tendência também é encontrada em estudos de inventários florísticos em florestas tropicais (Terborgh e Andresen 1998). Bush (1995) faz uma comparação entre mecanismos reprodutivos e a representação de grãos de pólen no registro polínico. Ele encontrou que plantas monóicas e dióicas são mais bem representadas do que as hermafroditas. Isso explicaria em parte, a baixa freqüência de Byttneria, Gomphrena e Caryophyllaceae (menos que 3 grãos cada) registrada em nosso estudo. Em relação à espécies raras, e como pode ser observado no diagrama polínico, a maioria dos grãos encontrados pode ser considerados raros (<3% da associação) ou aparecendo somente uma vez no registro.

5.3.2- Famílias de angiospermas predominantes

No poço 1AS-27-AM (figura 19), cerca de 4330 grãos foram contados (com exceção a contagem dos esporos). Em 28% da associação não foi possível determinar a afinidade botânica/ecológica dos grãos. Esses elementos aparecem raramente na associação (muitas vezes somente um grão é encontrado) e/ou possuem morfologia simples, o que dificulta comparações com grãos descritos e conhecidos atualmente. Resultados

57 similares são descritos em Bush (1995), onde 70-98% são grãos identificados a nível genérico ou de família. Cerca de 30 famílias puderam ser identificadas e a seqüência de abundância foi: Arecaceae, Poaceae, Bombacaceae (aqui essa família será mantida devido a diferença morfológica entre grãos de Bombacaceae e Malvaceae, Euphorbiaceae (Alchornea), Malpighiaceae, Humiriaceae (Humiria) e Melastomataceae (Miconia). Bush et al. 2001) afirmam que altos valores de pólen de Euphorbiaceae (Alchornea) associado com alta diversidade de grãos de pólen raros são bons indicadores da presença de floresta de terra-firme. Em todo perfil do poço foi encontrado pólen de Euphorbiaceae, sendo que na parte inferior em maior abundância. De acordo com Webster (2004) a maior diversidade genérica dessa família é encontrada na Amazônia, principalmente devido aos gêneros endêmicos dessa região. A figura abaixo (Figura 17) representa a contagem e predominância de grãos feita por amostra no poço 1AS-27-AM.

Figura 17: Diagrama palinológico com abundância de esporomorfos no poço 1AS-27-AM.

No poço 1AS-19-AM, somente 910 grãos foram contados, totalizando 19 famílias, sendo que Poaceae, Arecaceae, Malpighiaceae, Euphorbiaceae, Bombacaceae, Melastomataceae e Onagraceae tiveram predominância (fig. 18).

59 A composição e abundância nos dois poços apresentaram grande similaridade, poucas exceções podem ser ressaltadas como a presença de grãos de Polygonaceae.

Figura 18: Diagrama palinológico com abundância de esporomorfos a nível de família/gênero no poço 1AS-19-AM.

60 Gentry (1988) registra 11 famílias abundantes que são: Leguminosas, Lauraceae, Annonaceae, Rubiaceae, Moraceae, Myristicaceae, Sapotaceae, Meliaceae, Palmae (Arecaceae), Euphorbiaceae e Bignoniaceae, sendo que estas contribuem em média com 52% da riqueza de espécies em florestas neotropicais. Dentre essas 11 famílias, somente 7 foram encontradas no registro polínico, pois esses grãos são facilmente reconhecidos em nível de família e gêneros. De forma geral, a tabela abaixo mostra todas as famílias e gêneros encontrados na Amazônia durante o Mioceno Superior/Plioceno.

Tabela 6: Afinidade botânica de alguns fósseis Família Gênero Nome fóssil Acanthaceae Sanchezia Multimarginites vandehammenii Teliostachya Retitrescolpites? traversei Amaranthaceae Gomphrena Gomphrenipollis minimus Annonaceae Crematosperma Proxapertites tertiaria Apocynaceae Rauvolfia Retibrevitricolpites hoornii Arecaceae Mauritia M.franciscoi Asteraceae Tubuliflorae Echitricolporites spinosus Liguliflorae Fenestrites longispinosus Chloranthaceae Hedyosmum Clavainaperturites microclavatus Euphorbiaceae Croton Crototricolpites type, Crotonoideaepollenites reticulatus Sapium Horniella? caribbiensis Alchornea Ranunculacidites operculatus Humiriaceae Humiria Psilabrevicolporites devriesi Loranthaceae Loranthacites psilatus Malpighiaceae Brachypteris,Bunchosia, Perisyncolporites pokorny Hiraea, Mascagnia, Stigmatophyllum, Tetrapterys

Malvaceae Byttnerioidea: Byttnneria, Ayennia Byttneripollis ruedae Bombacoideae:Pachira Bombacacidites baculatus Bombacoideae:Ceiba Bombacacidites aracuarensis Bombacoideae: Quararibea Retistephanoporites crassiannulatus Bombacoideae: Bombacopsis Bombacacidites muinaneorum

61 Thespesia, Hibiscus ou Echiperiporites estelae Convolulaceae Melastomataceae Miconia Heterocplpites incomptus Onagraceae Ludwigia Corsinipollenites type Phyllanthaceae Amanoa, Pseudolachnostylis Retitrescolpites? irregularis

Poaceae Monoporopollenites annulatus Polygonaceae Polygonum Glencopollis curvimuratus Rubiaceae Psychotria Inaperturopollenites solimoensis

5.3.3 Primeiros registros de famílias e gêneros na Amazônia

Aproximadamente 200 morfo-espécies foram identificadas e alguns gêneros/famílias descritos pela primeira vez no registro fossilífero da Amazônia, devido a facilidade de reconhecimento morfológico. São eles: Sapium (Euphorbiaceae), Byttneria (Malvaceae), Polygonum (Polygonaceae), Rauvolfia e Geissospermum (Apocynaceae), Loranthaceae, Psychotria (Rubiaceae), Caryophyllaceae e Gomphrena (Amaranthaceae), sendo esses registros atualmente, muito importantes para a calibração de relógios moleculares. O RADAMBRASIL registra a presença da maioria dessas plantas atualmente na área de estudo. Na tabela 7 estão descritas as características botânicas dessas famílias. Essas informações foram retiradas de Ribeiro et al. (1999).

Tabela 7: Informações botânicas das famílias/Gêneros registrados pela primeira vez na Amazônia. Família Gênero Hábito Ambiente Amaranthaceae Gomphrena Ervas Ambientes pertubados Apocynaceae Geissospermum Árvores de dossel Platôs e vertentes Rauvolfia Árvores sub- Campinaranas bosque Caryophyllaceae herbáceo ou Pioneiras em subarbustivo solos expostos Euphorbiaceae Sapium Árvores Platôs e vertentes Loranthaceae Hemi-parasitas Polygonaceae Polygonum Rubiaceae Psychotria Vários hábitos Vários ambientes

Como se pode observar com esses registros, a floresta Amazônica possuía representantes com vários hábitos e adaptados diferentes ambientes, indicando a presença de uma floresta bem-estruturada com árvores de dossel, árvores e arbustos de sub-bosque, hemi-parasitas e espécies pioneiras distribuídas em distintos ambientes.

5.3.4 Diversidade da Amazônia durante o Neógeno

Por muitos anos acreditou-se que a diversidade da Amazônia estava relacionada a eventos de especiação causados pelo isolamento da biota por meio da fragmentação de florestas por extensas áreas abertas tipo savana. Essa fragmentação teria ocorrido por adaptação das espécies frente às mudanças climáticas ocorridas no Quaternário (Haffer 1969). Essa hipótese foi amplamente discutida (Colinvaux et al. 2000) e atualmente dados moleculares tem suportado a diversificação da Amazônia antes das mudanças ocorridas no Pleistoceno. Corroborando com uma diversificação mais antiga do que a inicialmente proposta, Hooghiemstra e Van der Hammen (1998) compararam números de grãos de pólen e esporos encontrados em amostras de sedimentos do Mioceno e Quaternário de Caquetá na Colômbia e afirmaram que no Mioceno a Amazônia foi mais diversa do que é atualmente. Essa diversidade estaria relacionada à dinâmica ambiental ocasionada por incursões marinhas, mudanças na drenagem de rios e soerguimento da cordilheira oriental. Um fato também que deve ser ressaltado é a influência ocasionada pela conexão com a América do Norte por meio do Istmo do Panamá que ocorreu no Plioceno (Coates et al. 1992), permitindo a imigração de taxa entre esses continentes (Morley 2000). Fazendo-se a mesma comparação feita por Hooghiemstra e Van der Hammen (1998) foram encontrados em 33 amostras de sedimentos Mio/Pliocênicos 197 morfo-espécies. Absy (1979) registra em 72 amostras

63 de sedimentos retirados na localidade de Costa da Terra Nova, na Amazônia, apenas 91 tipos de grãos, corroborando com a afirmação acima citada. Entretanto, quando se refere à diversidade usando-se dados palinológicos, alguns fatores necessitam ser mencionados e levados em consideração antes de serem feitas essas comparações: 1) Ambiente de deposição seria um importante fator, sendo que ambientes lacustre teriam vantagem em relação a ambientes fluviais. 2) Número de grãos contados por amostra, pois quando maior o número de grãos contados maior será o número de espécies encontradas e, portanto, a diversidade será maior. 3) Estudos de Quaternário não fazem muita diferenciação entre esporos, sendo que sempre são criadas grandes categorias morfológicas tais como: monolete psilado, monolete verrugado, etc. 4) A separação morfológica de grãos é subjetiva, sendo que alguns palinológicos preferem juntar como mesma espécie grãos com variações morfológicas e outros, que preferem separar as espécies que são unidades morfologicamente distintas.

De qualquer modo, nossos dados sugerem que mais do que um aumento ou decréscimo no número de espécies entre o Terciário e Quaternário, a diversidade na Amazônia poderia ser explicada pela estabilidade no número de espécies ao longo do tempo geológico. Pelo menos, é o que se observa no Mioceno e Plioceno, onde não há grandes eventos de origens e extinções de espécies nos dois intervalos estudados. Essa ausência de eventos bem marcados dificulta também a aplicação de conceitos bioestratigraficos nessas seções. A razão de altas taxas de especiação e baixa de extinção usada para explicar a diversidade em florestas tropicais, não foi observada nesse estudo. Provavelmente, a escala temporal aqui estudada, tenha sido tão pequena a ponto de não mostrar nenhum padrão. No entanto, esse seria um dado que

64 poderia ser testado em outros estudos, principalmente aqueles que abordam estudos polínicos no Quaternário. De forma geral, no poço 1AS-19-AM observa-se grandes diferenças entre o número de espécies observadas entre amostras, porém isso se deve a grandes intervalos entre as amostragens. O número mínimo de espécies foi 25 (amostra 189) e máximo de 45 espécies (amostra 90) com média de 33 espécies. Entretanto, diferenças maiores são observadas no poço 1AS-27- AM, onde se encontra 19 espécies na amostra 400.5 m e 59 espécies na amostra 192 m com media de 35.5 espécies.

6.0 Conclusões

1) Foram descritas 112 morfo-especies encontradas em amostras de rochas do Neógeno da Amazônia, sendo essa a primeira revisão sistemática dos grãos já descritos para o Norte da América do Sul, resultando em sete novas combinações e cerca 51 novos grãos. Sendo muitos deles encontrados pela primeira vez no registro fossilífero. 2) Em relação à bioestratigrafia, foram encontrados dois marcadores estratigráficos anteriormente estabelecidos (Fenestrites spinosus e Psilatricolporites caribbiensis) e indicadores do Mioceno Superior e Plioceno. No entanto, devido a sua baixa freqüência (<3% da associação), foi aplicado métodos de Bioestratigrafia Quantitativa. Resultando, em novas biozonas que deverão ser testadas em outras seções para avaliar sua aplicabilidade. 3) Conforme já discutido em trabalhos paleontológicos, nenhuma evidência de áreas marinhas ou costeiras foi encontrada, sendo rejeitada, portanto, a hipótese de um “seaway” na Amazônia durante o Mioceno Superior. 4) Abundância de esporos, gramíneas e palmeiras sugerem a presença de áreas pantanosas e aquáticas. A presença de muitas famílias de angiospermas indica áreas de florestas de terra firme nas proximidades da localidade de deposição. 5) Sugerimos que a floresta foi bem estruturada com a presença de sub- bosques e dossel e grande diversidade de epífitas além de espécies pioneiras. 6) A diversidade no Mioceno/Plioceno pelo menos nos intervalos estudados não ocorreu devido a altas taxas de especiação somadas a baixas de extinção, aparentemente, o que se observa hoje na Amazônia é devido à longa estabilidade no número de famílias ao longo dos últimos milhões de anos.

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8.0 Anexos

72 ANEXO I: MANUSCRITO QUE SERÁ SUBMETIDO A PALAEONTOGRAPHICA B.

73 Neogene palynology of Upper Amazonas Basin, South America, Brazil.

Silane A. F. Da Silva1,2, Carlos A. Jaramillo2, Maria Lucia Absy1, Millerlandy Romero-Baez2.

1 Instituto Nacional de Pesquisas da Amazonia-INPA,. Coordenação de Pós- graduação em Ecologia-PGEC, Laboratório de Palinologia-CPBO. P.O Box- 478, Cep: 69011-970 Manaus, AM, Brazil.

2 Smithsonian Tropical Research Institute-CTPA. Apartado 0843-03092, Balboa, Ancon, Panamá.

Summary:

Neogene palynology in the North South America has been poorly studied. Most of the palynological studies have been conducted in the coastal regions of Colombia and Venezuela with the objective of improving the biostratigraphical framework to be applied to oil research. So far, very few have done a detailed palynological study emphasizing a taxonomic revision of the pollen grains and spores. We are presenting a taxonomic revision of the Neogene Brazilian Amazonia using core sediments collected from Solimões Formation in Amazonas state, Brazil. We studied 41 samples of two sections located in northwestern Amazonia. A total of 112 species were described, being 51 new species. In addition, 7 previously described species were also revised in order to apply valid genus, as suggested by the ICBN. The age of those sections were established based on the presence of Fenestrites longispinosus and Clavainaperturites microclavatus (Hedyosmum) as Late Miocene/Early Pliocene. We also used Unitary association analysis to improve the biochronological framework and to determine correlations between those sections. As biostratigraphical results we found that the sections are contemporaneous.

Keywords: Palynology- taxonomy- Pliocene- Amazonia- Unitary Association.

Zusammenfassung Die neogene Palynologie in Amazonien wurde bisher wenig erforscht. Die meisten Studien wurden in den Küstengebieten von Kolumbien und Venezuela mit dem Ziel durchgeführt, den palniostratographischen Rahmen zur Ölsuche zu verbessern. Es gibt bisher sehr wenige palynologische Studien mit dem Schwerpunkt auf taxonomischer Revision. Wir präsentieren eine palynologisch taxonomische Revision des neogenen basilianischen Amazonien mit Hilfe von Sedimenten aus Solimoes Formationen. Wir untersuchten 41 Arten zweier Sektionen in Nordwest Amazonien. Wir beschreiben insgesamt 112 Arten, von denen 51 neue Arten sind. Zusätzlich wurden 7 bereits beschriebene Arten revidiert um diese einer korrekten Gattung, wie vom ICBN vorgeschlagen, zuzuordnen. Wir benutzten die Unitary Association Analyse zur Bestimmung von biostratographischen Korrelationen zwischen diesen Sektionen, welche demnach gleichzeitig entstanden sind. Aufgrund des Vorkommens von Clavainaperturites microclavatus (Hedyosmum) datieren wir das Alter der Sedimente in das Pliozän. Schlusselworter: Palynologie – Taxonomie – Pliozän – Amazonien - Unitary Association

Table of Contents

1. INTRODUCTION ...... 3

2. METHODOLOGY ...... 3

2.1 STUDY AREA...... 3

2.2- BIOSTRATIGRAPHICAL ANALYSIS...... 4

2.3 PREPARATION OF THE SAMPLES AND DESCRIPTION OF THE GRAINS ...... 5

3. RESULTS...... 5

3.1 BIOSTRATIGRAPHYCAL RESULTS ...... 5

3.2 SYSTEMATICAL PART...... 7 3.2.1 SPORES...... 7 3.2.2 POLLEN ...... 22

5. ACKNOWLEDGEMENTS ...... 79 6. REFERENCES ...... 79

1. Introduction Few palynological studies in the northern South America have been conducted. Most of the research has discussed the vegetation response to both Pleistocene and Holocene climatic changes and human impacts (Bush Bush, 2005, 2005). Others have emphasized improvement of the Tertiary palynostratigraphical framework for oil exploration research in coastal zones from Colombia, Venezuela, Trinidad and Brazil. Miocene and Pliocene in the northern South America have been palynologically studied since the 1960’s (Germeraad, et al., 1968, Regali, et al., 1974, Lorente, 1986, Muller, et al., 1987 and Hoorn, 1993). Since that time, the same pollen and spores nomenclature has been used. However, some nomenclatural problems can be emphasized: 1) posterior studies have been accepted some invalid genera, mainly that ones described in Van der Hammen 1954, 1956a and b, that use recent pollen as species type to support the genera description (Jansonius and Hill, 1976) and 2) according to International Code Botanical Nomenclature-ICBN-St. Louis 2000 (article 20.2) generic names that use morphological characteristics should be avoid unless if it was published before 1912. In order to do a complete revision of the systematical nomenclature applied to pollen and spores in northwestern South America, a detailed description of the sporomorphs found in the Neogene sediments from Amazonia is herein present. A total of 112 species, proposing 51 new species and 7 new combinations are described.

2. Methodology

2.1 Study area The sediments herein studied were drilled by the CPRM-Brazilian Geological company-in the 1970’s to find out potential areas to lignite exploration. Approximately 80 wells were drilled in that area reaching Neogene sediments belonging to the Solimões Formation (Moraes-Rego, 1930; Caputo, 1984) in the Upper Amazonas area, Brazil. The Solimões Formation is lithologically composed by grayish to gray- greenish clays, separated by sandbanks, lignite and gipsy levels Caputo, 1973, Schobbenhaus, et al., 1984 typically deposited in a lacustrine/fluvial environments Caputo, 1973. The unity shows Miocene and Pliocene deposits and is paleontologically known by the vertebrate and invertebrate fossiliferous sites, found mainly in Acre state. Two cores were studied in the present study: The well 1AS-27-AM (04°17’S/67°5’W) with 402, 5 meters depth near to Tamanduá-Jutaí Rivers in Amazonas State, Brazil. The well 1AS-19-AM (04°33’S/69°10’W) with 255,70 meters deep, Felicidade–Rio Jandiatuba Rivers, near to São Paulo de Olivença city, Amazonas state, Brazil. Their locations and of the another wells studied in the same area can be observed in text-Fig. 1. In this work just the Upper part of Solimões Formation was analyzed. The presence of Fenestrites longispinosus indicates late Miocene/Early Pliocene Lorente, 1986. Clavainaperturites microclavatus characterizes Pliocene age based on First Appearance Datum (FAD) dated in Colombia as Zone II belonging to Early Pliocene Van der Hammen, et al., 1973.

2.2- Biostratigraphical analysis The Neogene biostratigraphical framework used in this work was compared with previous biozonations established by Germeraad, et al., 1968, Regali, et al., 1974, Lorente, 1986, Muller, et al., 1987 and Hoorn, 1993. However, to do some biostratigraphical correlation between our cores, we used Unitary Association method, herein cited as UA Guex, 1991. The UA method uses a species matrix to establish assemblages showing co-occurrences, superposition and/or exclusive relations between species. It creates a biochronological assemblages, describing a sequence of intervals of events. Taxa assemblages can be used to construct zones with chronological meaning and consequently, correlation between the different sections can be made. For detailed information, see Guex, 1991 and its application in Angiolini&Bucher, 1999 Mailliot, et al., 2006. The software PAST Hammer, et al., 2001 was used. 35 species were chosen to compose the analysis taken into account two considerations: 1) species that show narrow distribution (i.e., wide range species were removed) and 2) the species present in both sections.

2.3 Preparation of the samples and description of the grains The samples were prepared in ICP-Instituto Colombiano del Petroleo following the standard palynological method Traverse, 1988. About 41 samples were studied, and approximately 300 grains were counted by slide. The holotypes and paratypes described here were deposited in the Palynology Laboratory at the INPA-Instituto Nacional de Pesquisas da Amazônia- INPA/Manaus, Brazil. The sporomorphs are organized in genera alphabetical order. The new combinations are proposed when the genera used in the literature is an invalid name as discussed in Jansonius&Hills, 1976. To determine valid genera, we used the key to the genera fossil Jansonius, 1978. To indicate new species distinctive morphological characteristics were taken into account and at least two grains were measured. The coordinates are given using an England Finder (EF) slide. The pollen grains and spores were described using the nomenclature used by Punt, et al., 2007, and following descriptions based on Jaramillo&Dilcher, 2001. For pollen grains found in polar view, CPi (colpi length/equatorial diameter), equatorial length, equatorial width and equatorial diameter length/width and in equatorial view CEi (colpi length/polar diameter), polar diameter, equatorial diameter and polar/equatorial (P/E) measurements were taken. Spores found in lateral view were measured both equatorial diameter and polar diameter. Equatorial diameter length and equatorial diameter width were measured in polar view. To indicate the relation between the radius and the spore diameter, the TLI (radius length /(trilete spore diameter/2) and MLI (laesura length/(monolete spore diameter) also were taken.

3. Results

3.1 Biostratigraphical results

The biozonation established by Lorente (1986) were used to compare with our data. The Fenestrites longispinosus Interval Zone proposed to late Miocene/Early Pliocene is based on the first appearance of Stephanocolpites evansii and the top is characterized by the first occurrence of Alnipollenites verus. The Fenestrites longispinosus is present in the entire interval of the zone. The zone is divided in three subzones: Stephanocolpites evansii Interval Subzone, Psilatricolporites caribbiensis Interval Subzone, Echitricolporites-Alnipollenites Interval Subzone. Despite of the absence of the Stephanocolpites evansii, the assemblage found in the Amazonas sections indicates late Miocene/Early Pliocene, based on the presence of Psilatricolporites caribbiensis. Data input from Solimões Formation in Unitary association method were composed of 2 sections, 41 samples and 35 species data were used. The UA analysis resulted in 5 maximal cliques based on 11 residual maximal horizons, 2 contradictions and 2 unitary associations. The 5 maximal cliques were found in the samples: Oboh-Ikuenobe, et al., 19-11, (2) 19-2, (3) 27-98, (4) 19-6 and Oboh-Ikuenobe, et al., 27-60. The contradictions were found mainly in the pairs of cliques: 2-5 and 1-6. No forbidden graphs were generated. The biostratigraphic graph for the sporomorphs is in text-fig. 2 and it shows strong co-occurrences between all species (figure 2a) and their superposition (figure 2b).

3.1.1- Unitary association zones:

- UA 1 and UA 2 In text-figure 3 is a graphical representation of the species composition used to construct each UA. The UA 1 is composed by 77% of the assemblage. The presence of Margocolporites muelleri n. sp. is restricted to this zone. The sections are contemporaneous according to UA reproducibility. The well 1AS-27-AM showed assemblages of all UA’s and it worked as a model to compare with another section. The correlation between sections and relationship with UA’s is in text-Fig. 4. Comparisons between sections were based on the extension of the UA’s range assumed by the presence of the lowest and uppers UA’s assemblages. 3.2 Systematical part

3.2.1 SPORES

Genus Cingulatisporites Pflug&Thomson, 1953 in Thomson&Pflug, 1953

Cingulatisporites pteriformis n. sp. Plate 1, Figs. 1,2,3

Diagnosis: Trilete, triangular-obtuse-convex, mid-sized (39-40 µm), laevigate on the both faces, marginate. Specimens: AM27-24, EF: O 46 ½, pl. 1, figs 1,2,3, AM27-2, EF: K39 2 Description: Spores single, symmetry radial, triangular-obtuse-convex; trilete, curvatura absent, radii ~17 µm, TLI 1, commissurae raised, borders convex, ends rounded, margo very thick, 3 µm thick, margo protruding, highly distinct, reaching the equator; sporoderm 1 µm thick; cingulate, cingulum 7 µm thick, decreasing to 4 µm towards radial area; sculpture laevigate on both faces. Dimensions: equatorial diameter length 39 (39.5) 40 µm, SD 0.7; equatorial diameter width 37(40.5) 44 µm, SD 4.9; P/dv length/width 1, n=2. Comparisons: Cingulatisporites Pflug&Thomson, 1953 in Thomson&Pflug, 1953 accommodates cingulate trilete spores.

Cingulatisporites rugulatus n. sp. Plate 1, Figs. 4,5,6

Diagnosis: Trilete, triangular-obtuse-convex to circular, mid-sized (22 µm), rugulate on proximal face and scabrate on the distal face, cingulate, curvatura perfecta. Specimens: Holotype: AM27-31, EF: W26 ¾, pl. 1, figs 4,5,6 Type locality: Well 1AS-27-AM Etymology: After the ornamentation on proximal face Description: Spores single, symmetry radial, triangular-obtuse-convex to circular; trilete, curvatura perfecta present, TLI 1, commissurae waving, margo distinct; sporoderm 1 µm thick; cingulate, cingulum 2 µm thick; sculpture rugulate on proximal face and scabrate on distal face. Dimensions: equatorial diameter length 22 µm; equatorial diameter width 22 µm; P/dv length/width 1, n=1. Comparisons: Cingulatisporites ornatus (van Hoeken-Klinkenberg 1964) has cingulum thicker (5 µm) and laesura indistinct.

Genus Crassoretitriletes Germeraad, et al., 1968

Crassoretitriletes vanraadshoovenii Germeraad et al. 1968. Plate 1, Fig. 7

Diagnosis: Trilete, triangular-obtuse-convex to subcircular, big-sized (51-80 µm), reti-fossulate. Specimens: AM27-22, EF: M55 2/4; 27-153, EF: N26 3 pl. 1, fig. 7 Description: Spores single, symmetry radial, triangular-obtuse-convex to subcircular, rounded corners; trilete, curvatura absent, radii 28 µm, TLI 0.87, margo absent, comissurae straight, ends pointed; sporoderm thick, sporoderm 5 µm thick; sculpture reti-fossulate, coarsely reticulate, muri 3 µm wide, 4 µm high, lumina varying from elongated to circular, 2-3 µm wide. Dimensions: equatorial diameter length 51 (62.5) 80 µm, SD 12.8; equatorial diameter width 55 (63.5) 80 µm, SD 11.6; P/dv length/width 1, n=4.

Genus Cyathidites Couper 1963 emend. Romanovskaya 1980

Cyathidites sp. 1 Plate 1, Figs. 8,9

Diagnosis: Trilete, triangular-obtuse-concave, mid-sized (35 µm), slightly cingulate, laevigate, granulate near to laesurae. Specimens: AM27-19, EF: V33 1/2 pl. 1, figs 8,9 Description: Spores single, symmetry radial, triangular-obtuse-concave; trilete, curvatura perfect, radii 18 µm, TLI 1, reaching the equator, margo 0.5 µm near to equator, increasing to 1 µm near to trilete mark, commissurae straight; intexine 0.4 µm thick; cingulate, cingulum 2 µm thick; sculpture laevigate, granulate near to laesurae. Dimensions: equatorial diameter length 35µm; equatorial diameter width 36 µm; equatorial/polar diameter 1 µm, n=1. Comparisons: Cyathidites Couper 1963 emend. Romanovskaya 1980 accommodates triangular spores with rounded angles and straight to concave sides (Jansonius & Hills, 1983, card 4084).

Genus Deltoidospora Miner, 1935 Potonié, 1956

Deltoidospora adriennis Potonié&Gelletich, 1933 Frederiksen, 1983 Plate 1, Figs. 16

Diagnosis: Trilete, triangular-obtuse-convex to subcircular, big-sized (43-85 µm), laevigate. Specimens: AM27-26, EF: L49 3/4 pl. 1, figs 16 Description: Spores single, symmetry radial, triangular-obtuse-convex to subcircular, rounded corners; trilete, curvatura absent, radii 15 µm, TLI 0.66, margo absent, comissurae straight, ends pointed; intexine 2 µm thick; sculpture laevigate on both faces. Dimensions: equatorial diameter length 43 (59.3) 85 µm, SD 22.5; equatorial diameter width 45 (60) 87 µm, SD 23.4; P/dv length/width 1, n=3.

Genus Distaverrusporites Muller, 1968

Distaverrusporites margaritatus Muller, 1968 Plate 1, Figs. 11,12,13,14

Diagnosis: Trilete, triangular-obtuse-convex, mid-sized (26 µm), gemmate- verrucate on distal face and laevigate on proximal face. Specimens: AM27-27, EF: U51 ½ pl. 1, figs 11,12,13,14 Description: Spores single, symmetry radial, triangular-obtuse-convex; trilete, curvatura absent, radii 13 µm, TLI 1.0, margo 1 µm, commissurae straight; at the end of each radii, there are prominent gemmae that are larger than the another; intexine 1 µm thick; sculpture gemmate-verrucate on distal face, 4 µm high, 3-4 µm wide, verrucae also are present, 2 µm high, 3 µm wide, both verrucae and gemmae are mixed together, no pattern were observed, laevigate on proximal face. Dimensions: equatorial diameter length 26 (27) 28 µm, SD 1.4; equatorial diameter width 23 (23.5) 24 µm, SD 0.7; equatorial/polar diameter 1.2, n=2.

Genus Echinatisporis Krutzsch, 1959

Echinatisporis circularis n. sp. Plate 1, Figs. 15,16

Diagnosis: Trilete, circular to subtriangular, mid-sized (17-23µm), echinate on both proximal and distal faces, spines cylindrical, curvatura perfecta. Specimens: Holotype AM27-23, EF: Y34 1 pl. 1, figs 15,16, paratype: AM27- 23, EF: M 24 1. Type locality: Well 1AS-27-AM Etymology: After the spore shape Description: Spores single, symmetry radial, circular; trilete, curvatura perfecta, laesura distinct, radii 10 µm, TLI 1, margo absent, commissurae straight; intexine 1 µm thick; sculpture echinate, echinae 1.5- 2 µm high, 1 µm thick, 1-2 µm apart, spines cylindrical, tips pointed. Dimensions: equatorial diameter length 17 (20) 23 µm, SD 4.2; equatorial diameter width 16 (18) 20 µm, SD 2.8; equatorial/polar diameter 1.1 µm, n=2. Comparisons: Echitriletes muelleri Regali, et al., 1974 has longer spines (> 6 µm and larger (32-35 µm). Echinatisporis minutus Van der Kaars, 1983 has laesura indistinct. Echinatisporis brevispinosus Jaramillo&Dilcher, 2001 has margo.

Echinatisporis muelleri Regali et al. 1974 n. comb. Plate 1, Fig. 21

1974 Echitriletes muelleri Regali et al., p. 265 pl. 14, Fig. 8.

Diagnosis: trilete, circular, mid-sized (27 µm), echinate, spines 6-9 long, sparsely distributed. Specimens: AM27-30, EF: X26 3 pl. 1, fig. 21 Description: Spores single, symmetry radial, circular; trilete, curvatura indistinct, laesura also indistinct; intexine 1.5 µm thick; sculpture echinate, echinae 6-9 µm long, 1-2 µm thick, 7 µm apart, sparsely distributed, echinae present in both faces, surface interspines laevigate. Dimensions: equatorial diameter length 27 µm; equatorial diameter width 20 µm; equatorial/polar diameter 1.4 µm, n=1. Comparisons: Echitriletes Van der Hammen 1955 is a nomen nodum Jansonius&Hills, 1976. Echitriletes Potonié 1956 accommodates trilete megaspores (Jansonius&Hills, 1976). Echinatisporis Krutzsch, 1959 accommodates spores triangular-convex to subcircular spores with spines distributed all over spore surface.

Genus Foveotriletes Van der Hammen ex Potonié, 1956

Foveotriletes ornatus Regali, et al., 1974 Plate 1, Figs. 17,18

Diagnosis: Trilete, triangular-obtuse-convex, mid-sized (28µm), foveolate on distal face and laevigate on proximal face, intexine decreases towards radial area. Specimens: AM27-23, EF: W 30 1/2, pl. 1, figs. 17,18 Description: Spores single, symmetry radial, triangular-obtuse-convex; trilete, curvatura absent, radii long, TLI 1.0, commissurae simple, margo absent, borders straight, ends distinct; intexine 1.5 µm thick, decreasing to 0.5 µm towards radial area; sculpture laevigate on the proximal face, foveolate on the distal face, foveos 0.5-1 µm wide, circular, 2-3 µm apart. Dimensions: equatorial diameter length 28 µm; equatorial diameter width 29 µm; P/dv length/width 1, n=1.

Genus Hydrosporis KRUTZSCH, 1962

Hydrosporis minor n. sp. Plate 1, Figs. 23,24

Diagnosis: Trilete, circular, small-sized (15-17 µm), laevigate, thin margo, margo granulate, thick exine. Specimens: Holotype AM27-17, EF: U28 ½ pl. 1, figs 23,24 Type locality: Well 1AS-27-AM Etymology: After the small size of the spore. Description: Spores single, symmetry radial, circular; trilete, curvatura absent, laesura distinct, radii 8 µm, TLI 1.0, reaching the equator, margo very thin, margo <1µm, granulate, commissurae straight; intexine very thick, 1.5 µm thick; sculpture laevigate, thickness constant. Dimensions: equatorial diameter length 15 (16) 17 µm, SD1.4; equatorial diameter width 16 µm; P/dv length/width 1 µm, n=2. Comparisons: Hydrosporis Krutzsch, 1962 accommodates laevigate spores with morphology that are known in Salvinia and Azolla’s spores Jansonius&Hills, 1976 card 1278. Psilatriletes martinensis SARMIENTO, 1992 has thicker sporoderm (3-4 µm) Affinities: Salvinia, Salviniaceae.

Genus Kuylisporites Potoníe, 1956

Kuylisporites waterbolkii Potoníe, 1956 Plate 1, Figs. 19,20

Diagnosis: Trilete, triangular-obtuse-straight, mid-sized (29 µm), laevigate. Specimens: AM27-2, EF: E36 1, pl. 1, figs 19,20 Description: Spores single, symmetry radial, triangular-obtuse-straight; trilete, curvatura absent, laesura distinct, radii 10 µm, TLI 0.7, almost reaching the equator, margo absent, commissurae straight, ends pointed, corners flats; interradial thickening with a aperture resembling a large pori, rounded, 8 µm wide; intexine 1-3 µm thick; sculpture laevigate. Dimensions: equatorial diameter length 29 µm; equatorial diameter width 31 µm; P/dv length/width 0.9 µm, n=1.

Genus Magnastriatites Germeraad et al. 1968

Magnastriatites grandiosus Kedves&De Porta, 1963 Dueñas, 1980 Plate 1, Fig. 22

Diagnosis: Trilete, triangular-obtuse-straight, big-sized (76 µm), cicatricosate on distal face, laevigate on proximal face. Specimens: AM27-1, EF: T31 ½ pl. 1, fig. 22 Description: Spores single, symmetry radial, triangular-obtuse-straight; trilete, curvatura absent, laesura distinct, radii 20 µm, TLI 0.3, margo 2 µm, commissurae straight; sporoderm 2-layered, 5 µm thick; sculpture cicatricosate on distal face, striae 3 µm high, 4 µm wide, 3 µm apart, laevigate on proximal face. Dimensions: equatorial diameter length 56 (64.6) 76 µm, SD 7.6; equatorial diameter width 55 (64.4) 75 µm; P/dv length/width 1.0 µm, n=9.

Genus Matonisporites Couper, 1958 emend. DETTMANN, 1963

Matonisporites muelleri Playford 1982 Plate 1, Figs. 29,30

Diagnosis: Trilete, triangular-obtuse-straight, mid-sized (24-30µm), laevigate. Specimens: AM27-2, EF: S25 2, pl. 1, figs 29,30 Description: Spores single, symmetry radial, triangular-obtuse-straight; trilete, curvatura perfect, radii 12 µm, TLI 1.0, reaching the equator, margo thin, 1 µm thick commissurae straight to waving; intexine1 µm thick, thickness increasing towards radial area to 1.5 µm; sculpture laevigate. Dimensions: equatorial diameter length 24 (39.7) 65 µm, SD 22.1; equatorial diameter width 20 (34.7) 60 µm, SD 22; equatorial/polar diameter 1.2 µm, n=3.

Genus Microfoveolatosporis Krutzsch 1959

Microfoveolatosporis sp.1 Plate 1, Figs, 27, 28

Diagnosis: Monolete, reniform, mid-sized (51µm), foveolate, marginate. Specimens: AM27-23, EF: L35 ¾ pl. 1, figs. 27,28 Description: Spores single, symmetry bilateral, reniform; monolete, curvatura absent, laesura with 30 µm, MLI 0.58, marginate, margo 2 µm wide, margo segmented, commissurae straight, ends pointed; intexine 2.0 µm thick; sculpture foveolate, foveolae 1-2 µm wide, 2-3 apart, 0.5-1 µm deep, circular to slightly elongate, uniformly distributed. Dimensions: equatorial diameter 52 µm; polar diameter 32 µm; equatorial/polar diameter 1.6, n=1. Comparisons: Microfoveolatosporis Krutzsch 1959 accommodates monolete and foveolate spores with foveolae shallow and rounded. Foveomonoletes Van der Hammen, 1954 ex MATHUR, 1966 also accommodates foveolate monolete spores. However, the type species, Foveomonoletes brevitriletes, is smaller (39µm), the mark is smaller (17µm) and has margo poorly developed. Microfoveolatosporis skottsbergii Selling, 1946 Srivastava, 1971 is larger (60- 89µm) and foveolae are densely distributed.

Genus Polypodiaceiosporites Potonié 1951 ex Potonié 1956

Polypodiaceiosporites? laevigatus n. sp. Plate 1, Figs. 25,26

Diagnosis: Trilete, triangular-obtuse-straight, mid-sized (28-40µm), fossulate on distal face and laevigate on proximal face. Specimens: Holotype: AM27-2, EF: K38 3 pl. 1, figs 25,26 Description: Spores single, symmetry radial, triangular-obtuse-straight, corners rounded; trilete, curvatura absent, radii ~10 µm, TLI 0.7, almost reaching the equator, commissurae straight, ends rounded to pointed; intexine 1 µm thick; cingulate, cingulum 2 µm thick; sculpture fossulate on distal face, fossulae varying from rounded to elongated, of 2 to 10 µm long, borders rounded, 1-2 µm wide, muri 1.5 wide, laevigate on proximal face. Dimensions: equatorial diameter length 28 (34) 40µm, SD 6; equatorial diameter width 32 (34) 36 µm, SD 2; P/dv length/width 1, n=3. Comparisons: Polypodiaceoisporites? fossulatus Jaramillo&Dilcher, 2001 is verrucate on proximal face. Polypodiaceiosporites pseudopsilatus Lorente, 1986 is rugulate on distal face. Cingulatisporites verrucatus Regali, et al., 1974 is verrucate and has cingulum thicker (6-8 µm thick). Foveotriletes sp. 1 (Jaramillo & Dilcher, 2001) is not cingulate.

Polypodiaceiosporites pseudopsilatus Lorente 1986 Plate 2, Figs. 1,2,3

1994a Psilatriletes peruanus Hoorn, p. 234, Pl. 2, Fig.10

Diagnosis: Trilete, triangular-obtuse-straight, mid-sized (27 µm), foveo- fossulate-rugulate on distal face and laevigate on proximal face, with a triangular ridge in distal face. Specimens: AM27-2, EF: K38 3 pl. 2, figs 1,2,3 Description: Spores single, symmetry radial, triangular-obtuse-straight, corners rounded; trilete, curvatura absent, radii indistinct in the observed grains, margo distinct, 2 µm wide, commissurae almost reaches the equator, commissurae straight, ends pointed; sporoderm 1-layered, intexine 1 µm thick; cingulum 2-3 µm thick, decreasing in radial region; sculpture foveolate- fossulate-rugulate on distal face, laevigate on proximal face, with a triangular ridge in distal face. Dimensions: equatorial diameter length 27 µm; equatorial diameter width 27 µm; P/dv length/width 1, n=1.

Genus Polypodiisporites Potonié1931? in Potonié&Gelletich, 1933 ex 1956, emend. Khan&Martin, 1972

Polypodiisporites aff. specious Sah, 1967 Plate 2, Figs. 6,7

Diagnosis: Monolete, reniform, mid sized (42-44 µm), verrucate on the distal face and scabrate on proximal face. Specimens: AM27-33, EF: L53 ½ pl. 2, figs 6,7 Description: Spores single, symmetry bilateral, reniform; monolete, curvatura absent, laesura indistinct; intexine 1 µm thick; sculpture verrucate on distal face, warts 1-2µm high, 2-3 µm wide and scabrate on the proximal face, evenly distributed. Dimensions: equatorial diameter 42 (43) 44 µm, SD 1.4; polar diameter 30 (30.5) 31 µm, SD 0.71; equatorial/polar diameter 1.4, n=2. Comparisons: Polypodiisporites aff. specious Sah, 1967 accommodates a wide variation of spores that have warts flats. Polypodiisporites usmensis Van der Hammen, 1956 Germeraad, et al., 1968 Khan&Martin, 1972 is also gemmate.

Polypodiisporites pseudoreticulatus n. sp. Plate 2, Figs. 4,5

2001 Polypodiisporites aff. inangahuensis, Jaramillo & Dilcher, 2001, p. 104, Pl.3, Figs.16,17,18

Diagnosis: Monolete, reniform, mid-sized (48-49 µm), positive reticulum, verrucate on distal face and scabrate on proximal face. Specimens: Holotype AM27-23, EF: Q33 2 pl. 2, figs 4,5, paratype AM27-22, EF: S31 3. Type locality: Well 1AS-27-AM. Etymology: After the false reticulum. Description: Spores single, symmetry bilateral, reniform; monolete, curvatura absent, laesura length 32 µm, MLI 0.6, commissurae straight to slightly convex; intexine 2.5µm thick; sculpture verrucate, verrucae narrow, forming a negative reticulum, uniformly distributed, scabrate on proximal face. Dimensions: equatorial diameter 48 (48.5) 49 µm, SD 0.7; polar diameter 34 (36) 38 µm, SD 2.8; equatorial/polar diameter 1.4 µm, n=2. Comparisons: Polypodiisporites specious Sah, 1967 and Polypodiisporites aff. specious Sah, 1967 do not form negative reticulum.

Polypodiisporites usmensis Van der Hammen, 1956 Germeraad, et al., 1968 Khan&Martin, 1972 Plate 2, Figs. 8,9

Diagnosis: Monolete, reniform, mid-sized (35-42 µm), verrucate-gemmate in both faces. Specimens: AM27-25, EF: D54 3 pl. 2, figs. 8,9 Description: Spores single, symmetry bilateral, reniform; monolete, curvatura absent, laesura 25 µm long, MLI 0.7, commissurae straight; intexine 1 µm thick; sculpture verrucate and gemmate, verrucae 1-2 µm high, 2 µm wide, gemmate, gemmae 3 µm high, 3 µm wide, 1-2 µm apart, warts distributed uniformly for whole surface. Gemmae more prominent on the extremities of the grain. Dimension: equatorial diameter length 35 (38.5) 42 µm, SD 4.95; equatorial diameter width 20 (24) 28 µm, SD 5.66; P/Dv length/width 1.7, n=2. Equatorial diameter 32 µm, polar diameter 16 µm, equatorial/polar diameter 2, n=1.

Polypodiisporites? planus n. sp. Plate 2, Figs. 10,11

Diagnosis: Monolete, reniform, mid-sized (35-41µm) clavate-gemmate on distal face and scabrate on proximal face. Specimens: Holotype AM27-20, EF: Q43 2, pl. 2, figs 10,11, paratype: 27-46, EF: Y36 1 Type locality: Well 1AS-27-AM Etymology: After the top of the clave shape Description: Spores single, symmetry bilateral, reniform; monolete, curvatura absent, laesura 25 µm, MLI 0.6, commissurae straight; intexine 1 µm thick; sculpture clavate to gemmate, sculpture 3 µm high, 2-3 µm wide, 3-5 µm apart, rounded to polygonal in plain view, head of clavae is not well developed, sometimes looks like a box, sparsely distributed, scabrate on proximal face. Dimensions: equatorial diameter 35 (38) 41µm, SD 4.2; polar diameter 20 (21.5) 23 µm, SD 2.1; equatorial/polar diameter 1.8, n=2. Comparisons: Polypodiisporites aff. inangahuensis Couper, 1953 Potonié, 1956 emend. Pocknall&Mildenhall, 1984, Polypodiisporites specious Sah, 1967 and Polypodiisporites aff. specious Sah, 1967 are verrucate. Polypodiisporites sp. 1 (Jaramillo & Dilcher, 2001) is smaller (26-35µm) and densely clavate.

Genus Psilatriletes Van der Hammen, 1956, Van der Hammen, 1954 ex Potonié, 1956

Psilatriletes lobatus Hoorn, 1994 Plate 2, Figs. 12,13

Diagnosis: Trilete, triangular-obtuse-convex, mid-sized (25 µm), laevigate, interradial crassitude. Specimens: AM27-33, EF: V22 4, pl. 2, figs. 12,13 Description: Spores single, symmetry radial, triangular-obtuse-convex; trilete, curvatura absent, laesura distinct, radii 7 µm, TLI 0.7, slightly marginate 1 µm, commissurae straight, ends pointed; intexine 0.5 µm, interradial crassitude well developed, 3 µm in radial area increasing to 8 µm towards interradial area; sculpture laevigate. Dimensions: equatorial diameter length 26 µm; equatorial diameter width 29 µm; P/dv length/width 0.9 µm, n=1.

Psilatriletes sp.1 Plate 2, Figs. 14,15

Diagnosis: Trilete, circular, mid-sized (15-17 µm), laevigate, trilete mark reaches the equator. Specimens: AM27-26, EF: K 63 3 pl. 2, figs 14,15 Description: Spores single, symmetry radial, circular; trilete, curvatura absent, laesura distinct, radii 10 µm, TLI 0.7, margo <1µm, commissurae convex, ends pointed; sporoderm 1-layered, intexine 0.4 µm thick; interradial crassitude, 2 µm thick, decreasing to 0.5 µm towards radial region; sculpture laevigate with small perforations on distal face. Dimensions: equatorial diameter length 26 µm; equatorial diameter width 17 µm; P/dv length/width 1 µm, n=1. Comparisons: Psilatriletes lobatus (Hoorn, 1994a) the interradial crassitude is thicker (8 µm).

Genus Pteridaceoisporis SUN&HE, 1980

Pteridaceoisporis gemmatus n. sp. Plate 2, Figs. 16,17,18

Diagnosis: Trilete, triangular-obtuse-convex, mid-sized (28-42µm), rugulate on distal face and gemmate on proximal face, thick cingulum. Specimens: Holotype AM27-2, EF: U 39 4, pl. 2, figs 16,17,18, paratype: AM27-2, EF: V24 1 Type locality: Well 1AS-27-AM Etymology: After the gemmate sculpturing Description: Spores single, symmetry radial, triangular-obtuse-convex; trilete, curvatura absent, radii 10 µm, TLI 0.6, margo absent or indistinct, comissurae concave, ends pointed; intexine 0.8 µm thick; cingulate, cingulum very thick, 5 µm thick; sculpture rugulate on distal face, rugulae 7 µm long, 2 µm wide, 5 µm apart, sparsely distributed, on distal face near to equator there is a zonate ridge just above the cingulum, verrucate, verrucae 1-2 µm long, 1 µm high and 1 µm apart, gemmate on proximal face, gemmae 1-2 µm high, 1 µm wide, 2 µm apart, circular, densely distributed. Dimensions: equatorial diameter length 28(34.7) 42 µm, SD 7; equatorial diameter width 37(38.3) 40 µm, SD 1.5; P/dv length/width 0.9, n=3. Comparisons: Pteridaceoisporis Sun & He 1980 accommodates triangular to circular spores with cingulum, verrucae on distal face and verrucae, granulae or scabrate on proximal face Jansonius&Hills, 1983 card 4145. Polypodiaceoisporetes pseudopsilatus LORENTE, 1986 has proximal face laevigate. Polypodiaceoisporites? fossulatus JARAMILLO&DILCHER, 2001 is verrucate-fossulate.

Genus Retitriletes Pierce 1961

Retitriletes altimuratus n. sp Plate 2, Figs. 25,26

Diagnosis: Trilete, circular, mid-sized (39-40 µm), reticulate, muri raised. Specimens: Holotype: AM27-10, EF: U29 2, pl. 2, figs. 25,26 paratype: AM27- 8, EF: Q29 2 Type locality: Well 1AS-27-AM Etymology: After the raised condition of the muri. Description: Spores single, symmetry radial, circular; trilete, laesura indistinct; intexine 1 µm thick; sculpture reticulate, lumina 2-3 µm wide, polygonal, evenly distributed, muri 0.5 µm thick, the point of intersection of the muri is raised to 1 µm. Dimensions: equatorial diameter length 39 (39.5) 40 µm, SD 0.71; equatorial diameter width 36 (37) 38 µm, SD 1.4; P/dv length/width 1.4 µm, n=2. Comparisons: Retitriletes sp. 1 (Jaramillo & Dilcher, 2001) is larger (60 µm), muri is taller (2 µm) and lumina wider (5-7 µm).

Genus Rugulatisporites Pflug&Thomson, 1953 in Thomson&Pflug, 1953

Rugulatisporites sp. 1 Plate 2, Figs. 21, 22

Diagnosis: Trilete, triangular-obtuse-convex, mid-sized (27 µm), laevigate on proximal face and rugulate on distal face. Specimens: AM27-8, EF: Y36 ½ pl. 2, figs 21, 22 Description: Spores single, symmetry radial, triangular-obtuse-convex; trilete, curvatura absent, laesura distinct, short, radii 11 µm, TLI 0.7, margo absent, comissurae slightly waving and concave, ends pointed; intexine 0.5 µm thick; sculpture laevigate on proximal face and rugulate on distal face, muri 0.5 um wide, 3-4 µm long, elongated, groove 0.5 µm apart, evenly distributed on proximal face. Dimensions: equatorial diameter length 27 µm; equatorial diameter width 31 µm; P/dv length/width 0.9 µm, n=1. Comparisons: Rugulatisporites Pflug&Thomson, 1953 in Thomson&Pflug, 1953 accommodates trilete spores that has elongated elements with uniform heights and irregularly distributed Jansonius&Hills, 1976, card 2460. Camarozonosporites sp. 1 Jaramillo&Dilcher, 2001 has interradial crassitude.

Genus Tuberositriletes Doring 1964

Tuberositriletes? crassus n. sp. Plate 2, Figs. 19,20

Diagnosis: Trilete, triangular-obtuse-convex, mid-sized (27-30µm), verrucate on distal and proximal faces, interradial crassitude. Specimens: Holotype AM27-18, EF: V32 3/4 pl. 2, figs 19,20 Type locality: Well 1AS-27-AM Etymology: After the presence of interradial crassitude. Description: Spores single, symmetry radial, triangular-obtuse-convex; trilete, curvatura absent, radii 12 µm, TLI 0.8, margo absent or indistinct, commissurae almost reaches the equator, commissurae straight, ends pointed; intexine 1 µm thick, increasing to 2-3 µm towards interradial region; interradial crassitude, 2-3 µm thick; sculpture verrucate, on proximal face verrucae shorter, 1 µm wide, rounded, on distal face is bigger, 1-3 µm high, 1 µm apart. Dimensions: equatorial diameter length 27 (28.5) 30 µm, SD 2.1; equatorial diameter width 27 (28.5) 30 µm, SD 2.1; P/dv length/width 1, n=2. Comparisons: These specimens are provisionally inserted in this genus. Tuberositriletes no accommodates spores that have interradial crassitude. Psilatriletes lobatus (Hoorn, 1994a) is psilate.

Genus Verrucatotriletes Van Hoeken-Klinkenberg, 1964

Verrucatotriletes bullatus VAN HOEKEN-KLINKENBERG, 1964 Plate 2, Figs. 23,24

Diagnosis: Trilete, triangular-obtuse-straight, mid-sized (30 µm), verrucate. Specimens: AM19-5, EF: J32 3/4 pl. 2, figs 23,24 Description: Spores single, symmetry radial, triangular-obtuse-straight; trilete, curvatura absent, laesura distinct, long, reaching the equator, radii 18 µm, TLI 1.0, margo absent, commissurae straight; intexine 1 µm thick; sculpture verrucate on both proximal and distal faces, irregularly distributed, on distal face are larger 10 µm wide and 3 µm high, on proximal face, 3 µm wide, 2 µm high, circular to elongated. Dimensions: equatorial diameter length 30 µm; equatorial diameter width 25 µm; P/dv length/width 1.2 µm, n=1.

3.2.2 POLLEN

Genus Arecipites Wodehouse, 1933 emend. Nichols, et al., 1973 Arecipites perfectus n. sp. Plate 3, Figs. 1, 2

Diagnosis: monocolpate, prolate, mid-sized (39-46 µm), micropitted, tectate, colpi mid-sized, borders straight, ends pointed, tapered. Specimens: Holotype AM27-23, EF: O23 ½ pl. 3, figs. 1,2, paratype AM27-32, EF: R22 4 Biochronological range: from UA 1 to UA 3. Etymology: After the perfect sculpture of the grain. Description: Monad, bilateral, anisopolar, prolate; monocolpate, colpi mid- sized, ends pointed, borders straight, tapered, colpi simple, colpi 38 µm long, CEi 0.4; tectate, exine 1 µm thick, nexine 0.3 µm thick, columellae 0.3 µm high, distinct, tectum 0.4 µm thick; sculpture micropitted, lumina < 0.3 µm, circular to elongated, densely distributed, regular, muri <0.3 µm thick. Dimensions: polar diameter 39 (42.9) 46 µm, SD 2.9, equatorial diameter 25 (26.8) 28 µm, SD 1.5, polar/equatorial 1.6, n=4. Comparisons: Arecipites Wodehouse, 1933 emend. Nichols, et al., 1973 accommodates monosulcate grains, tectate with colpi tapered (Jansonius and Hill, 1976, card 166). Psilamonocolpites amazonicus Hoorn, 1993 is psilate and columellae indistinct. Arecipites regio (Van der Hammen & Garcia, 1966) Jaramillo & Dilcher, 2001 has colpi reaching the poles and slightly marginate. Retimonocolpites claris Sarmiento, 1992 is semitectate and colpi rounded.

Arecipites? polaris n. sp. Plate 3, Figs. 3, 4

Diagnosis: monocolpate, prolate, mid-sized (20-24 µm), micropitted, tectate, colpi almost reaching the poles, borders straight, ends pointed, isopolar. Specimens: Holotype AM27-29, EF: X55 1/3, pl. 3, figs. 3,4, paratype AM27- 29, EF: Q45 4 Type locality: Well 1AS-27-AM Etymology: After the rounded polar area of the grain. Description: Monad, bilateral, isopolar, elliptic; monocolpate, colpi long, ends pointed, borders straight, colpi 18 µm long, CEi 0.75; tectate, exine 1 µm thick, columellae indistinct; sculpture micropitted, lumina 0.5 µm wide, densely distributed. Dimensions: polar diameter 20 (22) 24 µm, SD 2.8, equatorial diameter 14 (14.5) 15 µm, SD 0.7, polar/equatorial 1.5, n=2. Comparisons: Arecipites perfectus n. sp. is larger (39-46 µm) and colpi shorter. Psilamonocolpites nanus Hoorn, 1993 and Psilamonocolpites amazonicus Hoorn, 1993 are psilate.

Genus Bombacacidites Couper, 1960

Bombacacidites araracuarensis Hoorn, 1994 Plate 3, Figs. 5, 6

Diagnosis: Tricolporate, reticulate, triangular-obtuse-convex, mid-sized (25-39 µm), semitectate, Bombacacidites-type, pluricolumellate, nexine scabrate, homobrochate, lumina wide, evenly distributed over entire grain. Specimens: AM27-4, EF: S64 3 pl. 3, figs. 5, 6, AM27-22, EF: V39 3. Description: Monad, radial, isopolar, triangular-obtuse-convex; tricolporate, ectocolpi 16 µm wide, CEi 0.61, colpi costate, costae 1.5 µm wide, 2 µm thick, pointed ends, endopores costate, costae 1.5 µm wide, lalongate; semitectate, exine 2 µm thick, nexine 0.5 µm thick, columellae 1 µm thick, distinct, 1 µm wide, 2-3 µm apart, densely scabrate, columellae increases towards muri, tectum 0.5 µm thick; sculpture reticulate, homobrochate, lumina 3-4 µm wide, 3-4 µm long, muri 1 µm wide, pluricolumellate. Dimensions: equatorial length 25 (32) 39 µm, SD 9.9; equatorial width 26 (31) 36 µm, SD 7.1; equatorial diameter length/width 1, n=2. Natural affinities: Ceiba petandra, Malvaceae.

Bombacacidites fossulatus n. sp. Plate 3, Figs. 14,15,16

Diagnosis: Tricolporate, triangular-obtuse-convex, mid-sized (29-44µm), fossulate, colpi short, straight, semitectate, Bombacacidites-type fossulate. Specimens: Holotype AM27-3, EF: R26 2/4 pl. 3, figs. 15,16, paratype: AM27- 17, EF: V54 3, pl. 3, figs. 14, AM27-25, EF: V25 4 Type locality: Well 1AS-27-AM Etymology: After the fossulate sculpturing. Description: Monad, radial, isopolar, triangular-obtuse-convex; tricolporate, colporus intersubangular, colpi short, straight, pointed to rounded ends, colpi 10 µm long, CEi 0.27, costate, costae 2.0 µm wide, 1 µm thick, costae surrounding the entire margin of the colpi; pores indistinct; semitectate, exine 1.8 µm thick, nexine 0.4 µm thick, columellae 1 µm thick, columellae 1 µm wide, distinct, <1 µm apart, regularly distributed, tectum 0.4 µm thick; sculpture fossulate, fossulae uniform at the apocolpia resembling a labyrinth, lumina 1µm wide, 10-12 µm long, muri 1 µm wide, simplicolumellate, gradually decreasing to foveolate towards interangular mesocolpia area, foveos, <0.5 µm wide, circular. Dimensions: equatorial length 29 (35.8) 44 µm, SD 5.1; equatorial width 28 (36.8) 47 µm, SD 6.5; equatorial diameter length/width 1, n=6. Comparisons: Bombacacidites protofoveoreticulatus (Jaramillo & Dilcher, 2001) has both costae (3 µm) and muri (1.5 µm) thicker; foveo-fossulate is uniformly distributed over entire grain. Intraspecific variability: Grains with colpi without costae also were observed.

Bombacacidites nacimientoensis Anderson, 1960 Elsik, 1968 Plate 3, Figs. 17,18

Diagnosis: Tricolporate, triangular-obtuse-straight, mid-sized (52 µm), reticulate, heterobrochate, tectate, simplicolumellate. Specimens: AM27-8, EF: J 47 2 pl. 3, figs. 17,18 Description: Monad, radial, isopolar, triangular-obtuse-straight, corners rounded; tricolporate, colpi 20 µm long, CEi 0.52, marginate, margo 2 µm thick, pores 2 µm wide, 2 µm high, costate, costae 2 µm wide; semitectate, exine 2 µm thick, nexine 0.4 µm thick, columellae 1.2 µm thick, distinct, tectum 0.4 µm thick; sculpture reticulate, lumina 1 µm wide, varying shape, heterobrochate, simplicolumellate, lumina decreasing towards mesocolpia, muri 0.5 µm thick, where becomes micropitted. Dimensions: equatorial length 52 µm; equatorial width 52 µm; equatorial diameter length/width 1, n=1. Comparisons: Bombacacidites nacimentoensis Anderson, 1960 Elsik 1968 is described as pluricolumellate. Every specimen observed here are simplicolumellate. Some grains described in Jaramillo and Dilcher (2001) are also simplicolumellate. Bombacacidites gonzalezii (Jaramillo and Dilcher, 2001) becomes psilate at mesocolpia. Bombacacidites ciriloensis (Muller et al. 1987) is multicolumellate and homobrochate.

Bombacacidites simpliciriloensis n. sp. Plate 3, Figs. 7, 8, 9

Diagnosis: Tricolpate, triangular-obtuse-convex, mid-sized (41-49µm), reticulate, simplicolumellate, semitectate, Bombacacidites-type, lumina decreasing towards apocolpia area. Specimens: Holotype AM27-5, EF: M51 1 pl. 3, figs. 7,8,9, paratype AM27-12, EF: O25 1. Type locality: Well 1AS-27-AM Etymology: After the similarity with Bombacacidites ciriloensis Muller, et al., 1987. Description: Monad, radial, isopolar, triangular-obtuse-convex; tricolpate, colpi short, simple, straight, pointed to rounded ends, colpi 18 µm long, CEi 0.36; semitectate, exine 1.5 µm thick, nexine 0.5 µm thick, columellae distinct, 1 µm thick, 1.5 µm wide, 1 µm apart, regularly distributed, tectum 0.5 µm thick; sculpture reticulate, heterobrochate, lumina 1 µm wide in the apocolpia, polygonal, gradually increasing towards mesocolpia, lumina 2-3 µm wide, 3-5 µm long, muri 0.8 µm, simplicolumellate. Dimensions: equatorial length 41 (45) 49 µm, SD 5.7; equatorial width 41 (46.5) 52, SD 7.8; equatorial diameter length/width 1, n=2. Comparisons: Bombacacidites ciriloensis Muller, et al., 1987 is pluricolumellate. Intraspecific variability: the presence of colpi marginate, margo 2 µm wide.

Bombacacidites zuatensis Lorente, 1986 Plate 3, Fig. 13

1993 Bombacacidites muinaneorum Hoorn, p. 302, pl. 2, fig. 19

Diagnosis: Tricolporate, triangular-obtuse-straight, mid-sized (20 µm), reticulate, heterobrochate, becoming psilate in the mesocolpia, semitectate, constriction in angular area. Specimens: AM27-15, EF: G32 2 pl. 3, fig. 13, 27-20, EF: U36 2 Description: Monad, radial, isopolar, triangular-obtuse-straight; tricolporate, brevicolporate 2 µm wide, colpi costate, costae 1 µm wide, 2 µm thick; pores 1 µm wide, pores 0.5 µm high, pores indistinct; semitectate, exine very thin, 0.7 µm thick, nexine 0.2 µm thick, columellae 0.3 µm thick, distinct, 0.5 µm wide, 1 µm apart, tectum 0.2 µm thick; sculpture reticulate, heterobrochate, lumina 0.5µm wide, decreasing abruptly towards angular mesocolpia area, where becomes psilate, the angular psilate area is constricted, circular to elongated, muri 0.3 µm thick, simplicolumellate. Dimensions: equatorial length 20 (25.3) 36 µm, SD 9.2; equatorial width 19 (26) 39 µm, SD 11.3; equatorial diameter length/width 1, n=3. Comparisons: We saw both holotypes (Bombacacidites zuatensis and Bombacacidites muinaneorum) and they are the same grain, just a variation in the angular area where a constriction was observed.

Bombacacidites sp.1 Plate 3, Figs. 10, 11, 12

Diagnosis: Tricolpate, circular, mid-sized (25-30 µm), foveoreticulate, semitectate. Specimens: AM27-23, EF: R36 3/4 pl. 3, figs. 10, 11, 12 Description: Monad, radial, circular; tricolpate, colpi very short, colpi 10 µm long, CEi 0.4, simple, borders straight, ends pointed; semitectate, exine 1 µm thick, nexine 0.3 µm thick, columellae distinct, 0.5 µm high, 1 µm apart, tectum 0.2 µm thick; sculpture foveo-reticulate, lumina 0.5 µm wide, 0.5 µm apart, slightly elongated to polygonal, homobrochate, foveos restricted to apocolpia area, muri 0.5 µm wide. Dimensions: equatorial length 25 (27.5) 30 µm, SD 3.5; equatorial width 26 (28) 30 µm, SD 2.8; equatorial diameter length/width 1, n=2. Comparisons: Retibrevitricolpites retibolus Leidelmeyer, 1966 is semitectate. Retibrevitricolpites triangulatus Van Hoeken-Klinkenberg, 1966 is triangular- acute-convex. Bombacacidites sp. 1 (Jaramillo and Dilcher, 2001) is brevicolpi costate.

Genus Byttneripollis KONZALOVA 1976

Byttneripollis ruedae n. sp. Plate 3, Figs. 21,22

Diagnosis: Triporate, triangular-obtuse-convex, mid-sized (19 µm), reticulate, muri undulating, semitectate, ectopores highly protruding, endopores costate. Specimens: Holotype AM27-19, EF: M28 4 pl. 3, figs 21,22 Type locality: 1AS-27-AM Etymology: In honor to D. Milton Rueda. Description: Monad, radial, isopolar, triangular-obtuse-convex; triporate, ectopores simple, protruding, 2 µm high, endopores costate, costae 3 µm thick, 3 µm wide, atrium is present; semitectate, exine 1 µm thick, nexine 0.3 µm thick, columellae distinct, 0.5 µm thick, tectum 0.2 µm thick; sculpture reticulate, lumina 0.5-1 µm wide, elongated to polygonal, heterobrochate, muri undulating, 0.5 µm wide. Dimensions: equatorial length 19 µm; equatorial width 18 µm; equatorial diameter length/width 1.1, n=1. Comparisons: Byttneripollis coronarius KONZALOVA 1976 is larger (35 µm) and has pores bigger (5 µm). Botanical affinities: Byttneria, Ayennia-Malvaceae

Genus Cichoreacidites Sah, 1967

Cichoreacidites longispinosus Lorente, 1986 n. comb. Plate 3, Figs. 26,27,28

1986 Fenestrites longispinosus Lorente p. 180, pl. 15, figs.1, 2

Diagnosis: Tricolporate, circular, mid-sized (22 µm), fenestrate, echinate, spinae with perforations at the base, tectate. Specimens: AM27-19, EF: G41 4 pl. 3, figs. 26,27,28 Description: Monad, radial, isopolar, circular; tricolporate, colpi seems like simple, pores indistinct; tectate, thin exine, exine 0.6 µm thick, nexine 0.2 µm thick, columellae 0.2 µm thick, distinct, columellae increases at the base of the spines, tectum 0.2 µm thick; sculpture fenestrate-echinate, lacunae 3-4 µm wide, circular to elongated, lophae 2 µm wide, spines 3-4 µm high, 3 µm apart, conical, sometimes join at the top with ridges, every single spine has one perforation in the base, perforation distinct. Dimensions: polar diameter 22 µm, equatorial diameter 19 µm, polar/equatorial 1.2, n=1; equatorial length 16 (20.3) 26 µm, SD 4.4; equatorial width 15 (20.3) 26 µm, SD 4.5; equatorial diameter length/width 1, n=6. Comparisons: Fenestrites Van der Hammen, 1956 is illegitimate and later synonym of Crepis paludosa M., because the type species was based on the recent pollen. Germeraad, et al., 1968 tried legitimate the genus, but the lectogenotype also was based on Crepis Jansonius&Hills, 1976 card 1012. Cichoreacidites Sah, 1967 accommodates tricolporate and grains with fenestrae and echinae on the ridges Jansonius&Hills, 1976 card 470. Variation: In some grains ridges join most of the spines.

Genus Cistacearumpollenites Nagy, 1969

Cistacearumpollenites rotundiporus n. sp. Plate 3, Figs. 19,20

Diagnosis: Tricolporate, prolate, mid-sized (21-24µm), reticulate, semitectate. Specimens: Holotype AM27-19, EF: S37 2 pl. 3, figs. 19,20, paratype: AM27- 19, EF: Q41 2 Type locality: Well 1AS-27-AM Etymology: After the pores shape. Description: Monad, radial, isopolar, prolate; tricolporate, colpi mid-sized, simple, borders slightly convex, ends rounded, colpi 15 µm long, CPi 0.6, pores slightly costate, costae 1 µm wide, pores 2 µm wide, pores 2 µm high, circular; semitectate, exine 1 µm thick, nexine 0.4 µm thick, columellae 0.4 µm high, 0.5-1 µm apart, distinct, tectum 0.2 µm thick; sculpture reticulate, lumina 0.5 µm wide, polygonal, densely distributed, muri 0.5 µm wide. Dimensions: polar diameter 21 (22.5) 24 µm, SD 2.1, equatorial diameter 15 (17.5) 20 µm, SD 3.5, polar/equatorial 1.3, n=2; Equatorial length 20 µm; equatorial width 20 µm; equatorial diameter length/width 1, n=1. Comparisons: Cistacearumpollenites Nagy, 1969 accommodates tricolporate pollen grains with rounded pores Jansonius&Hills, 1976, card 497. Retitricolporites porisconspectus Hoorn, 1994 has pores bigger (5µm) and it has operculum. Rhoipites hispidus (Van der Hammen and Wymstra, 1964) Jaramillo and Dilcher, 2001 has colpi costate. Retitricolporites santaisabelensis (Hoorn, 1994) has pores lalongate. Intraspecific variability: In the ornamentation, some shows a reticulate pattern, lumina 1 µm, heterobrochate, with lumina decreasing towards colpi.

Genus Clavainaperturites Van der Hammen&Wymstra, 1964

Clavainaperturites microclavatus Hoorn, 1994 Plate 3, Fig. 29

Diagnosis: Inaperturate, circular, mid-sized (20-23µm), clavate, intectate, sometimes folded, thick exine. Specimens: AM27-21, EF: X62 4 pl. 3, fig. 29 Description: Monad, radial, isopolar, circular; inaperturate; intectate, exine 1 µm thick; sculpture clavate, clavae 1 µm high, 0.3 µm thick, 0.3 µm wide, circular in plain view, 0.5 µm apart, densely distributed over entire grain. Sometimes, the grains are folded, showing a pentagonal fold in one side of the grain. Dimensions: equatorial length 20 (21) 23 µm, SD 1.7; equatorial width 18 (20.3) 23 µm, SD 2.5; equatorial diameter length/width 1, n=3.

Genus Corsinipollenites Nakoman, 1965

Corsinipollenites collaris n. sp. Plate 3, Figs. 32,33

Diagnosis: Triporate, triangular-obtuse-convex, mid-sized (37µm), pores circular, protruding, psilate, atectate, with a collar thickening. Specimens: Holotype AM27-15, EF: X 30 4 pl. 3, figs. 32, 33 Type locality: Well 1AS-27-AM Etymology: After the pores thickness resembling a collar. Description: Monad, radial, anisopolar, on proximal area there is a Y mark, on distal area the viscid threads are present, triangular-obtuse-convex; triporate, endopores annulate, annuli with 2 µm wide, 2 µm thick, pores 6 µm wide, pores 6 µm long, circular, highly protruding, at the base of the protruding there is a collar-like thickening surrounding the base of the pore, resembling a Normapollis structure; atectate, exine 1 µm thick; sculpture psilate. Dimensions: equatorial length 37 µm; equatorial width 30 µm; equatorial diameter length/width 1.2, n=1. Comparisons: Corsinipollenites undulatus Gonzalez, 1967 Jaramillo&Dilcher, 2001 has rugulate undulating. Corsinipollenites psilatus Jaramillo&Dilcher, 2001 lacks the collar structure. Psilabrevitricolporites triangularis (Van der Hammen & Wymstra, 1964) Jaramillo & Dilcher 2001 is tectate and the costae thicker (5 µm).

Corsinipollenites oculusnoctis Thiergart, 1940 Nakoman, 1965 Plate 3, Figs. 23,24 and 25

Diagnosis: Triporate, triangular-obtuse-convex, mid-sized (33-38 µm), pores lolongate, costate. Specimens: AM27-26, EF: E65 2 pl. 3, figs. 23,24, tetrads: AM27-26, EF: R64 4, pl 3, fig. 25 Description: Monad, radial, anisopolar, triangular-obtuse-convex; triporate, ecto and endopores coinciding, endopores costate, costae 2-3 µm wide, 2 µm thick, pores 3-5 µm wide, 3-5 µm long, lolongate, highly protruding; grains showing a fold resembling a Y mark on apocolpia area; tectate, exine 1 µm thick, nexine 0.3 µm thick, columellae 0.4 µm high, columellae indistinct, tectum 0.3 µm thick; sculpture psilate. Often tetrads are found, tetrads in tetrahedral arrangement. Dimensions: equatorial length 33 (35.3) 38 µm, SD 2.5; equatorial width 28 (33.3) 40 µm, SD 6.1; equatorial diameter length/width 1.1, n=3.

Corsinipollenites scabratus n. sp. Plate 3, Figs. 30, 31

Diagnosis: Triporate, triangular-obtuse-convex, mid-sized (35-39 µm), pores circular, protruding, costate and marginate, scabrate-verrucate, intectate, thick exine Specimens: Holotype AM27-15, EF: H35 2 pl. 3, figs. 30,31 Type locality: Well 1AS-27-AM Etymology: After the ornamentation of the grain. Description: Monad, radial, anisopolar, one of the poles has a distinct Y mark, the another side does not have a fold, triangular-obtuse-convex; triporate, ecto and endopores coinciding, pores costate and marginate, margo 2 µm wide, 3 µm thick, produced by a thin of the exine around the pores, pores 3 µm wide, pores 3 µm long, circular, highly protruding; intectate, exine 2 µm thick, exine decreases to 1.5 µm towards pores; sculpture scabrate, 0.5 µm wide, 0.5 µm apart, densely distributed over entire grain, verrucae isolated, randomly placed in over entire grain. Dimensions: equatorial length 35 (37) 39, SD 2.8; equatorial width 33; equatorial diameter length/width 1.1, n=2. Comparisons: Corsinipollenites undulatus Gonzalez, 1967 JARAMILLO&DILCHER, 2001 is rugulate. Corsinipollenites oculusnoctis Thiergart, 1940 Nakoman, 1965 is psilate.

Genus Cricotriporites Leidelmeyer, 1966

Cricotriporites sp. 1 Plate 4, Figs. 1,2

Diagnosis: Triporate, elliptic, mid-sized (25 µm), psilate-infrascabrate, atectate. Specimens: AM27-29, EF: L49 2/4 pl. 4, figs. 1,2 Description: Monad, radial, isopolar, elliptic; triporate, pores annulate, annulus produced by thickening of the exine, 1-2 µm wide, 1-2 µm thick, pores 2 µm wide, pores 2 µm long, circular; atectate, exine 0.5 µm thick, nexine 0.5 µm thick; sculpture psilate-infrascabrate, densely distributed over entire grain. Dimensions: equatorial length 25 µm; equatorial width 20 µm; equatorial diameter length/width 1.3, n=1. Comparisons: Cricotriporites Leidelmeyer, 1966 accommodates triporate grains with psilate sculpture, pores annulate/costate and a circular shape Jansonius&Hills, 1976 card 655. Cricotriporites minutiporus Muller, 1968 JARAMILLO&DILCHER, 2001 has pores bigger (3-5 µm).

Genus Crotonoideaepollenites Rao&Ramanujam, 1982

Crotonoideaepollenites reticulatus n. sp. Plate 4, Figs. 3,4

Diagnosis: Inaperturate, circular, mid-sized (42-48 µm), clavate-reticulate, intectate, crotonoid pattern. Specimens: Holotype AM19-1, EF: J33 3 pl. 4, figs. 3,4, paratype AM19-1, EF: T55 ½ Type locality: Well 1AS-19-AM Etymology: After the croton pattern associate with reticulate ornamentation. Description: Monad, radial, isopolar, circular; inaperturate; intectate, exine, exine 1 µm thick; sculpture clavate, clavae 3 µm high, the apices of clavae has 1 µm wide, 1 µm apart, showing croton pattern, the nexine is reticulate, the clavae are organized in a line on the top of the reticulum, lumina 1 µm wide, polygonal, muri 0.5-1 µm wide. Dimensions: equatorial length 42 (45) 48 µm, SD 4.2; equatorial width 48 µm; equatorial diameter length/width 0.9, n=2. Comparisons: Crotonoidaepollenites Rao&Ramanujam, 1982 accommodates inaperturate grains with crotonoid pattern Jansonius&Hills, 1976, card 4222. Crototricolpites annemariae Leidelmeyer, 1966 is tricolpate. Inaperturopollenites microclavatus (Regali et al. 1974) is tectate and larger (80µm). Intraspecific variation: thickness of the muri.

Genus Crototricolpites Leidelmeyer, 1966

Crototricolpites finitus n. sp. Plate 4, Figs. 5, 6, 7, 8, 9

Diagnosis: Tricolpate, circular, prolate, mid-sized (27 µm), clavate with croton- pattern only distinct in some areas of the grain, intectate, thick exine, internal body. Specimens: Holotype AM27-25, EF: C22 2 pl. 4, figs. 8, 9; paratype AM19-4, Q37 1 pl. 4, figs. 5,6,7; Type locality: Well 1AS-27-AM and 1AS-19-AM Etymology: due to the presence of the thin clavae. Description: Monad, radial, isopolar, circular, prolate; tricolpate, colpi long, intruding, simple, borders straight, ends rounded, colpi 24 µm long, CEi 0.72; intectate, exine 2 µm thick, nexine 2 µm thick; sculpture clavate, clavae 1 µm high, 0.5-1 µm apart, densely distributed, 0.5 µm wide, usually present distinct croton pattern, rounded to triangular in plain view, clavae increasing towards colpi aperture, with a distinct inner body, psilate that has exine 0.5 µm thick. Dimensions: polar diameter 27 µm, equatorial diameter 22 µm, polar/equatorial 1.2, n=1; Equatorial length 33 µm, equatorial width 33 µm, equatorial diameter length/width 1, n=1. Comparisons: Crototricolpites annemariae Leidelmeyer, 1966 is bigger (48 µm) and has exine thinner (0.7 µm). Crototricolpites protoannemariae JARAMILLO&DILCHER, 2001 has exine thinner (1 µm wide) and clave wider (1 µm wide). Intraspecific variation: in some grains the inner body are absente.

Genus Ctenolophonidites Van Hoeken-Klinkenberg, 1966

Ctenolophonidites suigeneris n. sp. Plate 4, Figs. 10,11,12

Diagnosis: Stephanocolpate, circular, mid-sized (25-39 µm), psilate, atectate, two ringlike are surrounding the colpi. Specimens: Holotype AM27-24, EF: N58 4 pl. 4, figs. 10, 11, 12, paratypes: AM27-15, EF: S37 3; AM27-7, EF: W65 4. Type locality: Well 1AS-27-AM Etymology: After the unnusual sculpture. Description: Monad, radial, anisopolar, circular; stephanocolpate, 4 brevicolpi, colpi 5 µm long, CEi 0.2, indistinct, simple, colpi lie by 2 short ridges, ridges 1 µm wide, 1 µm thick, 4 µm long, 1 µm apart, the small ridge is surrounded by a double ring-ridge, 7 µm wide, 1 µm thick, 0.5 µm apart from another ridge, 15 µm long, the double-ring is also present on the apocolpia; atectate, thin exine, exine 0.5 µm thick, thickening 1 µm thick in the ridges; surface inter- ridge psilate. Dimensions: equatorial length 25 (32) 39 µm, SD 7; equatorial width 20 (24.3) 31; equatorial diameter length/width 1.3, n=3. Comparisons: Ctenolophonidites Van Hoeken-Klinkenberg, 1966 accommodates stephanocolpate grains. Ctenolophonidites costatus Van Hoeken-Klinkenberg, 1964 Van Hoeken-Klinkenberg, 1966 has colpi costate and the ridge is one ring. Ctenolophonidites lisamae (Van der Hammen & Garcia, 1966) Germeraad et al. 1968 is scabrate and colpi costate. Verrustephanocolpites rugulatus (Jaramillo and Dilcher, 2001) is rugulate. Natural Affinities: Geissospermum, Apocynaceae.

Genus Dicolpopollenites Pierce, 1961

Dicolpopollenites obtusipolus n. sp. Plate 4, Figs. 13,14,15,16

Diagnosis: Dicolpate, prolate, mid-sized (32-40 µm), reticulate to micropitted, tectate, colpi long, borders straight, slightly tapered. Specimens: Holotype AM27-28, EF: S36 2 pl. 4, figs. 15,16, 27-19, EF: P38 ½ pl. 4, figs. 13,14. Etymology: After the shape of the grain. Type locality: Well 1AS-27-AM Description: Monad, radial, isopolar, prolate; dicolpate, colpi long, constricted in equatorial area, colpi 30 µm long, CPi 0.86, borders straight, ends rounded, marginate, margo 2 µm wide, margo produced by decreasing of the lumina towards colpi; tectate, exine 2 µm thick, nexine 0.5 µm thick, columellae 1 µm thick, distinct, tectum 0.5 µm thick; sculpture reticulate-micropitted, lumina 0.5 µm wide, rounded, densely distributed over entire grain, muri 0.5-1 µm thick. Dimensions: polar diameter 32 (36.3) 40 µm, SD 3.3, polar diameter 16 (20.8) 25 µm, SD 3.8, polar/equatorial 1.8, n=4.

Genus Echiperiporites Van der Hammen & Wymstra 1964

Echiperiporites estelae Germeraad et al. 1968 Plate 4, Figs. 17, 18, 19

Diagnosis: Pantoporate, circular, mid-sized (42 µm), echinate, spines taller than another specimens described here, tectate. Specimens: AM27-28, EF: F25 4 pl. 4, figs. 17, 18, 19 Description: Monad, radial, isopolar, circular; pantoporate, ectopores simple, endopores costate, costae with 2 µm thick, 10 pores, pores 3 µm wide, pores 3 µm high, circular; tectate, exine 2 µm thick, nexine 1 µm thick, columellae 0.8 µm thick, columellae increases towards echinae, tips distinct, rounded, < 0.4 µm wide, tectum 0.2 µm thick; sculpture echinate, spines 2 µm high, 2 µm wide, conical, 3 µm apart, interspines surface showing tips. Dimensions: equatorial length 42 µm; equatorial width 33 (40.5) 48 µm, SD 10.6; equatorial diameter length/width 1.1, n=2.

Echiperiporites jutaiensis n. sp. Plate 4, Figs. 20, 21

Diagnosis: Pantoporate, circular, mid-sized (28-30 µm), ecto/endopores coinciding, endopores costate, echinate, tectate, nexine very thick, 7-11 pores. Specimens: Holotype AM27-24, EF: E57 2 pl. 4, figs. 20, 21 Type locality: Well 1AS-27-AM Etymology: After the Brazilian river name, where the well 1AS-27-AM was drilled. Description: Monad, radial, isopolar, circular; pantoporate, ecto/endopores coinciding, endopores costate, costae 3 µm wide, 1 µm thick, 7-11 pores, pores 1.5 µm wide, pores 1.5 µm high, circular; tectate, exine 3.5 µm thick, nexine very thick, 3 µm thick, columellae 0.3 µm thick, indistinct, tectum 0.2 µm thick, the tectum above the costae lacks spines; sculpture echinate, echinae 1-2 µm high, 1 µm wide, 2-3 µm apart, conical. Dimensions: equatorial length 28 (29) 30 µm, SD 1.4; equatorial width 28 (28.5) 29 µm, SD 0.7; equatorial diameter length/width 1, n=2. Comparisons: Echiperiporites estelae GERMERAAD, ET AL., 1968 has spines longer (4-7µm) and exine thinner (1.6 µm). Echiperiporites akanthos VAN DER HAMMEN&WYMSTRA, 1964 has pore marginate. Echiperiporites sp. 1 Jaramillo&Dilcher, 2001 is bigger (90 µm) and spines smaller. Intraspecific variability: sometimes gemmae also are observed together echinae.

Echiperiporites intectatus n. sp. Plate 4, Figs. 26, 27

Diagnosis: Pantoporate, circular, pores annulate (3 µm), protruding, echinate, the spines could be in cluster or sparsely distributed usually near to pores, intectate. Specimens: Holotype AM27-13, EF: S27 pl. 4, figs 26, 27 Type locality: Well 1AS-27-AM Etymology: After of the unusual intectate pattern in Echiperiporites. Description: Monad, radial, isopolar, circular; pantoporate, pores annulate, annuli 2-3 µm wide, 2 µm thick, 11-18 pores are present, pores 2 µm wide, pores 2 µm high, circular, protruding; intectate, exine 1 µm thick; sculpture echinate, spines 1-2 µm high, 1 µm wide, sub-conical, slightly constricted in the base, showing two patterns in the distributions: 1) big spines organized in cluster, densely arranged with a distribution in patches, 1 µm apart, usually present near to pores, 2) small spines sparsely distributed, 3-4 µm apart, surface interspines slightly scabrate, scabrate 1 µm wide, < 0.5 µm high, 0.5 µm apart. Dimensions: equatorial length 25 (30.7) 37 µm, SD 6; equatorial width 22 (29) 35 µm, SD 6.6; equatorial diameter length/width 1.1, n=3. Comparisons: Echiperiporites estelae (Germeraad et al., 1968) is tectate. Psilaperiporites multiporus Hoorn, 1994 is psilate.

Echiperiporites lophatus n. sp. Plate 4, Figs. 22, 23

Diagnosis: Pantoporate, echinate, circular, tectate, columellae very high at the spine base, 30 pores, large, ornamentation resembling an echinolophate pattern. Specimens: Holotype AM27-7, EF: S24 pl. 4, figs. 22, 23 Type locality: Well 1AS-27-AM Etymology: After the ornamentation of the grain. Description: Monad, radial, isopolar, circular; pantoporate, endopores simple, 30 pores, pores 3 µm wide, pores 3 µm high, circular; tectate, exine 2.7 µm thick, nexine very thick, 2 µm thick, columellae 0.5 µm thick, distinct, columellae and tectum restricted to the bridge, resembling an echinolophate pattern, columellae increases in the base of echinae reaching 5 µm high, 0.5 µm wide, 0.5 µm apart, tectum 0.2 µm thick; sculpture echinate-lophate, spines very high, 8-10 µm high, 3 µm wide, 5 µm apart, conical, spines are restricted to the bridge surrounded to the pores, lophae 3 µm wide, polygonal, pluricolumellate, lacuna 6 µm wide, polygonal, in the middle of the lacuna lacks sexine. Dimensions: equatorial length 42 µm; equatorial width 33 (40.5) 48 µm, SD 10.6; equatorial diameter length/width 1.1, n=2. Comparisons: Echiperiporites estelae GERMERAAD, ET AL., 1968 has pores annulate. Echiperiporites akanthos VAN DER HAMMEN&WYMSTRA, 1964 has pores marginate. Echiperiporites sp. 1 Jaramillo&Dilcher, 2001 is bigger (90 µm).

Genus Foveotricolporites Pierce 1961

Foveotricolporites lenticuloides n. sp. Plate 4, Figs. 39, 40, 41, 42

Diagnosis: Tricolporate, prolate, mid-sized (34-36 µm), foveolate, tectate, pores in lens shape. Specimens: Holotype AM27-22, EFW39 ½ pl. 4, figs 39, 40; 27-60, EF: V23 1, paratype AM27-22, EF: W56 pl. 4, figs. 41, 42 Type locality: Well 1AS-27-AM Etymology: After the pores shape. Description: Monad, radial, isopolar, prolate; tricolporate, colpi long, colpi 29 µm long, CPi 0.8, simple, borders slightly convex, ends pointed, pores simple, lalongate, 10 µm wide, 3 µm high, lens shaped; tectate, exine 1.5 µm thick, nexine 0.5 µm thick, columellae 0.5 µm thick, indistinct, tectum 0.5 µm thick; sculpture foveolate, lumina 0.5 µm wide, elongated, densely distributed, muri 0.5 µm thick. Dimensions: polar diameter 28 (32.7) 36 µm, SD 4.2, equatorial diameter 20 (22.3) 24 µm, SD 2.1, polar/equatorial 1.5, n=3. Comparisons: Foveotricolporites caldensis Gonzalez, 1967 has exine thicker (2 µm) and colpi costate. Foveotricolporites marginatus Gonzalez, 1967 has colpi marginatus. Foveotricolporites florschutzi Van der Hammen, 1954 van der Hammen and Wymstra 1964 is smaller (18 µm).

Foveotricolporites pseudodubiosus n. sp. Plate 4, Fig. 31

Diagnosis: Tricolporate, triangular-obtuse-convex to circular, mid-sized (18-25 µm), foveolate, semitectate. Specimens: Holotype AM27-15, EF: W 26 4 pl. 4, fig. 31 Description: Monad, radial, isopolar, triangular-obtuse-convex to circular; tricolporate, ectocolpi simple, short, 16 µm long, CEi 0.72, endopores costate, costae 2-3 µm thick, very distinct, pores lalongate, pores 1 µm wide, pores 2 µm long; semitectate, exine 1 µm thick, nexine 0.3 µm thick, columellae 0.4 µm, tectum 0.3 µm thick; sculpture reticulate, lumina 0.5 µm wide, 0.5-2 µm long, homobrochate, most of the lumina is rounded, but lumina elongated are also found, densely distributed, multicolumellate, muri 1 µm wide. Dimensions: equatorial length 18 (21.7) 25 µm; equatorial width 20 (23.7) 26 µm; equatorial diameter length/width 0.9, n=3. Comparisons: Retitriporites poriscostatus Jaramillo&Dilcher, 2001 has pores bigger (4µm). Retitriporites federicii Gonzalez, 1967 has larger lumina (3 µm). Retitriporites dubiosus Gonzalez, 1967 is triporate. Foveotricolporites sp. 1 (Jaramillo & Dilcher, 2001) has endopores with fastigium.

Genus Glencopollis Pocknall&Mildenhall, 1984 Glencopollis curvimuratus n. sp. Plate 4, Figs. 32, 33, 34

Diagnosis: pantoporate?, mid-sized (25-26µm), reticulate, polygonum-type, circular, semitectate. Specimens: Holotype AM19-8, EF: V43 1 pl. 4, figs. 32, 33, 34, paratype: AM19-8, EF: J58 4 Type locality: Well 1AS-19-AM Etymology: After the muri pattern. Description: Monad, radial, isopolar, circular; pantoporate?; sometimes lighter areas inside of the lumina is visible, resembling pores aperture; semitectate, exine 3 µm thick, nexine 1 µm thick, nexine echinate in the lumina, spines 0.5 µm wide, 0.5 µm high, 0.5 µm apart, columellae 1.5 µm thick, distinct, 1 µm wide, 2-3 µm apart, tectum 0.5 µm thick, restricted to columellae; sculpture reticulate, lumina 4 µm wide, homobrochate, elongated to circular, 14 lumina are present on the proximal face, muri very thick, 2.0 µm wide, curvimurate, pluricolumellate. Dimensions: equatorial length 25 (25.5) 26 µm, SD 0.7; equatorial width 23 (23.5) 24 µm, SD 0.7; equatorial diameter length/width 1.1, n=2. Comparisons: Glencopollis Pocknall&Mildenhall, 1984 accommodates with affinity to the family Polygonaceae. Retitriporites mirabilis Regali, et al., 1974 has the same reticulum pattern but it is porate. Retipollenites confusus Gonzalez, 1967 has reticulum that is not inserted in the exine.

Genus Gomphrenipollis Anzotegui&Cuadrado, 1996

Gomphrenipollis minimus n. sp. Plate 4, Figs. 24, 25

Diagnosis: Inaperturate, fenestrate, circular, small-sized (14-17µm), 32 lacunas are present, semitectate. Specimens: Holotype AM27-23, EF: Q39 ½ pl. 4, figs. 24, 25, paratype: AM27-1, EF: U33 3 Type locality: Well 1AS-27-AM Etymology: After the small size of the grain. Description: Monad, radial, isopolar, circular; inaperturate; semitectate, thin exine, exine 1.3 µm thick, nexine 0.2 µm thick, columellae 0.8 µm thick, 1 µm wide, 5 µm apart, baculae also is present, 0.7 µm high, <0.5 µm wide, <0.5 µm apart, elongated in plain view, elongation is orthogonal to the lophae, given a segmented aspect inside of the lophae, tectum 0.3 µm thick; the columellae, tectum and nexine are restricted to the base of the lophae; sculpture fenestrate, 27 lacunae are present showing a pattern 9-9-9, lacunae 4 µm wide, hexagonal to pentagonal, lophae 1 µm wide, 2 µm high. Dimensions: equatorial length 14 Oboh-Ikuenobe, et al., 17 µm, SD 1.5; equatorial width 15 (16) 17 µm, SD 1.5; equatorial diameter length/width 1, n=3. Comparisons: Gomphrenipollis Anzotegui&Cuadrado, 1996 accommodates spherical, reticulate, periporate (Sic, Jansonius&Hills, 1976 card 5121) with morphology similar to Gomphrena, Amaranthaceae. Jansonius and Hills, 1976 have suggested the invalid name due the absence of the Holotype information, but they valided the genus name (Jansonius, Hills & Hartkopf- Froder, 1988). Natural affinities: Gomphrena, Amaranthaceae.

Genus Heterocolpites Nagy, 1969

Heterocolpites brevicolpatus n. sp. Plate 4, Figs. 28, 29, 30

Diagnosis: Heterocolpate, sub-prolate, small-sized (16-17 µm), psilate, tectate, pores indistinct, colpi constricted. Specimens: Holotype AM19-1, EF: S19 3 pl. 4, figs. 28, 29, 30; paratype: AM19-1, EF: S26 ½ Type locality: Well 1AS-19-AM Etymology: After the colpi size. Description: Monad, radial, isopolar, subprolate; heterocolpate, 6 aperture-3 colpi alternating with 3 colporus, colpi simple, colpi mid-sized, colpi 8 µm long, CPi 0.5, borders straight, constricted, ends indistinct, pores very small, simple, indistinct, pores 1.5 µm wide, pores 1.5 µm high, circular; tectate, exine 1 µm thick, nexine 0.2 µm thick, columellae 0.4 µm high, indistinct, tectum 0.4 µm thick; sculpture psilate. Dimensions: equatorial length 16 (16.5) 17 µm, SD 0.7, equatorial width 15 µm, equatorial diameter length/width 1.1, n=2. Comparisons: Heterocolpites paluster Gonzalez, 1967 has exine thicker (2 µm) and colpi marginate. Heterocolpites palaeocenica (Van der Hammen and Garcia, 1966) has colpi longer, almost reaching the equator. Heterocolpites incomptus Hoorn, 1993 has pores lalongate.

Heterocolpites rotundus Hoorn, 1993 Plate 4, Figs. 35, 36

Diagnosis: Heterocolpate, subprolate, mid-sized (18-21 µm), psilate, tectate, pores circular. Specimens: AM27-26, EF: F48 3 pl. 4, figs. 35, 36 Description: Monad, radial, isopolar, prolate; heterocolpate, 6 apertures, 3 colpi, 3 colporus, colpi alternating with colporus, colpi simple, colpi mid sized, 10 µm long, CPi 0.55, borders straight, ends indistinct, pores 3 µm wide, 3 µm high, circular, simple; tectate, exine 1 µm thick, nexine 0.3 µm thick, columellae 0.4 µm high, indistinct, tectum 0.3 µm thick; sculpture psilate. Dimensions: polar diameter 18 (19) 21 µm, SD 1.7, equatorial diameter 12 (14) 15 µm, SD 1.7, polar/equatorial 1.4, n=3.

Heterocolpites verrucosus Hoorn, 1993 Plate 4, Figs. 37, 38

Diagnosis: Heterocolpate, circular, prolate, small-sized (16 µm), verrucate, tectate. Specimens: AM27-26, EF: L60 2 pl. 4, figs. 37,38: AM27-26, EF: E47 4 Description: Monad, radial, isopolar, circular, prolate; heterocolpate, 6 apertures, 3 colpi, 3 colporus, colpi alternating with a colporus, colpi mid- sized, colpi 8 µm long, the colpi are often difficult to see, borders straight, ends indistinct, pores 3 µm wide, pores 3 µm high, circular; tectate, exine 1.5 µm thick, nexine 0.5 µm thick, columellae 0.5 µm high, indistinct, tectum 0.5 µm thick; sculpture verrucate, verrucae triangular to rounded, 0.5 µm high, 1 µm wide, densely distributed. Dimensions: polar diameter 14 (16.4) 19 µm, SD 2.1, equatorial diameter 12 (14.4) 16 µm, polar/equatorial 1.2, n=5; Equatorial length 15 µm; equatorial width 15 µm; equatorial diameter length/width 1, n=1.

Genus Horniella Traverse, 1955

Horniella? caribbiensis Muller, et al., 1987 n. comb. Plate 4, Figs. 43, 44

1986 Psilatricolporites caribbiensis Lorente, p. 194, pl. 20, fig. 4 1987 Psilatricolporites caribbiensis Muller et al., p. 48, pl. 4, figs. 9,10.

Diagnosis: Tricolporate, prolate, large-sized (48-52 µm), tectate, psilate. Specimens: AM27-1, EF: S26 4 pl. 4, figs. 43, 44 Description: Monad, radial, isopolar, prolate, polar area is rounded; tricolporate, colpi long, 45 µm long, CPi 0.86, intruding, borders straight, ends reaching the polar area, pores slightly costate, costae 1-2 µm wide, 1 µm high, pores 8 µm wide, pores 6 µm high, lalongate; tectate, exine 2 µm thick, nexine 0.2 µm thick, columellae 1.4 µm thick, indistinct, 0.5 µm apart, 0.5 µm wide, tectum 0.5 µm thick; sculpture psilate. Dimensions: polar diameter 48 (50) 52 µm, SD 2.8, equatorial diameter 36 (40) 44 µm, SD 5.7, polar/equatorial 1.3, n=2. Comparisons: Psilatricolporites Van der Hammen, 1956 ex Pierce, 1961 is an obligate later synonym of Tricolporites Van der Hammen, 1954, because they have the same type species Jansonius&Hills, 1976 card 2234). Horniella TRAVERSE 1955 accommodates tricolporate, reticulate, prolate, and with thin or lacing margo or colpicostate pollen grains (FREDERIKSEN 1983). Jaramillo and Dilcher, 2001 have psilate grains in this genus. Retitricolpites simplex Gonzalez, 1967 is very similar but it is reticulate.

Horniella morenoi n. sp. Plate 5, Figs. 1, 2

Diagnosis: Tricolporate, prolate, mid-sized (21-28 µm), micropitted, heterobrochate, tectate, pores costate, lalongate, colpi simple. Specimens: Holotype AM27-18, EF: U23 1 pl. 5, figs. 1, 2; paratype: AM27-9, EF: Y25 4 Type locality: Well 1AS-27-AM Etymology: in honor to Colombian palynologist, Enrique Moreno Description: Monad, radial, isopolar, prolate; tricolporate, colpi mid-sized, colpi 15 µm long, CPi 0.5, borders straight, ends pointed, pores slightly costate, costae 2 µm thick, pores 7 µm wide, pores 4 µm high, lalongate; tectate, exine 1 µm thick, nexine 0.3 µm thick, columellae 0.5 µm high, 0.5 µm thick, 0.5 µm wide, 1 µm apart, distinct, tectum 0.2 µm thick; sculpture micropitted, lumina 0.5 µm wide, circular, densely distributed, muri 0.3 µm wide. Dimensions: polar diameter 21 (23.8) 28 µm, SD 2.6; equatorial diameter 15 (19) 25 µm, SD 3.9; polar/equatorial 1.3, n=6. Comparisons: Horniella sp. 3 (Jaramillo & Dilcher, 2001) has pores fastigiate. Retitricolporites microreticulatus Herngreen, 1975 has pores simple. Retitricolporites ellipticus VAN HOEKEN-KLINKENBERG, 1966 has colpi costate. Intraspecific variability: sculpture varies of micropitted to reticulate (lumina 1 µm wide), decreasing towards colpi.

Horniella? megaporata n. sp. Plate 5, Figs. 11,12

Diagnosis: Tricolporate, prolate, small-sized (13 µm), psilate, tectate, large pores, lalongate. Specimens: Holotype: 27-75, EF: R52 ½ pl. 5, figs. 11,12 Type locality: Well 1AS-27-AM Etymology: After the big size of the pores. Description: Monad, radial, isopolar, prolate; tricolporate, colpi slightly costate, costae < 1 µm thick, borders straight, ends rounded, almost reaching the equator, colpi 9 µm long, CPi 0.69, pores simple, pores 5 µm wide, pores 2 µm high, lalongate, very large; tectate, exine 1.1 µm thick, nexine 0.3 µm thick, columellae 0.3 µm high, indistinct, tectum 0.5 µm thick; sculpture psilate. Dimensions: polar diameter 13 µm, equatorial diameter 11 µm, polar/equatorial 1.2, n=1. Comparisons: Psilatricolporites garzonii Hoorn, 1993 has thicker exine, pores slightly lalongate, smaller pores size. Psilatricolporites magniporatus Hoorn, 1993 has colpi costate. Psilatricolporites obesus Hoorn, 1993 and Psilatricolporites silvaticus Hoorn, 1993 has exine thicker towards equator.

Genus Ilexpollenites Thiergart, 1938 Potonié, 1960

Ilexpollenites tropicalis n. sp. Plate 5, Figs. 13, 14, 15

Diagnosis: Tricolporate, prolate, mid-sized (25 µm), clavate, clavae increasing to polar area, intectate. Specimens: Holotype AM27-24, EF: J58 ½ pl. 5, figs. 13,14,15, paratype AM27-24, EF: G56 2 Type locality: Well 1AS-27-AM Etymology: After the tropical zone that it is found. Description: Monad, radial, isopolar, prolate, circular; tricolporate, colpi costate, costae 2 µm wide, borders straight, ends rounded, gaping, colpi 16 µm long, CPi 0.64, pores simple, pores width indistinct, pores 3 µm long; intectate, exine 4 µm thick; sculpture clavate, clavae 2-3 µm high, increasing towards polar area, 1 µm wide, surface of clavae is scabrate. Dimensions: polar diameter 25 µm, equatorial diameter 18 µm, polar/equatorial 1.4, n=1. Equatorial length 30 µm, equatorial width 21 µm, equatorial diameter length/width 1.4, n=1. Comparisons: Ilexpollenites megagemmatus McIntyre, 1968 is gemmate and has colpi almost indistinct. Ilexpollenites clifdenensis McIntyre, 1968) has nexine and sexine of almost equal thickness. Ilexpollenites anguloclavatus McIntyre, 1968) has clavae with angular top. Ilexpollenites verrucatus Pocknall&Mildenhall, 1984 is tricolpate and verrucate/gemmate.

Genus Inaperturopollenites Pflug&Thomson, 1953 in Thomson&Pflug, 1953

Inaperturopollenites solimoensis Leite, (in press) Plate 5, Figs. 5,6

Diagnosis: Inaperturate, circular, mid-sized (32-40 µm), reticulate, semitectate, simplicolumellate. Specimens: AM27-29, EF: Q64 ¾ pl. 5, figs. 5, 6 Description: Monad, radial, isopolar, circular; inaperturate; semitectate, thin exine, exine 1 µm thick, nexine 0.3 µm thick, columellae 0.4 µm thick, tectum 0.3 µm thick; sculpture reticulate, lumina1-2 µm wide, heterobrochate, simplicolumellate, densely distributed, pentagonal, circular to oval, muri 0.5 µm wide. Dimensions: equatorial length 32 (36) 40 µm, SD 5.7; equatorial width 29 µm; equatorial diameter length/width 1.2, n=2. Comparisons: Inaperturopollenites curvimuratus Regali, et al., 1974 is tectate and has curvimurate reticulum. Retipollenites sp.1 (Jaramillo & Dilcher, 2001) has tectum thicker (4 µm), lumina wider (4-8 µm). Retipollenites confusus Gonzalez, 1967 has lumina larger (1.5 µm) and exine thicker (3 µm).

Genus Ladakhipollenites Mathur&Jain, 1980

Ladakhipollenites floratus n. sp. Plate 5, Figs. 3, 4

Diagnosis: Tricolpate, circular, mid-sized (23-26µm), colpi long, psilate, tectate, colpi long, marginate, thin margo. Specimens: Holotype AM27-23, EF: S 27 1/3 pl. 5, figs. 3,4 Type locality: Well 1AS-27-AM Etymology: After the grain shape similarity with a flower. Description: Monad, radial, isopolar, circular; tricolpate, colpi long, 24 µm long, CEi 0.92, marginate, margo 2 µm wide, produced by a thinning of the exine, borders straight, ends pointed; tectate, exine 1 µm thick, nexine 0.2 µm thick, columellae 0.6 µm thick, indistinct, tectum 0.2 µm thick, columellae decreasing towards colpi, small polar area, 5 µm wide; sculpture psilate. Dimensions: equatorial length 23 (24.5) 26 µm, SD 2.1; equatorial width 25 (26.5) 28, SD 2.1; equatorial diameter length/width 0.9, n=2. Comparisons: Ladakhipollenites Mathur&Jain, 1980 accommodates tricolpate grains with colpi long, exine psilate to faintly and obscurely sculpture Jansonius&Hills, 1976. Psilatricolpites papilioniformis Regali, et al., 1974 is faint striate. Ladakhipollenites sp. 1 (Jaramillo & Dilcher, 2001) has colpi membrane gemmate. Psilatricolpites clarissimus Van der Hammen, 1954 van der Hammen and Wymstra, 1964 has columellae distinct. Ladakhipollenites simplex Gonzalez, 1967 Jaramillo and Dilcher, 2001 is highly prolate, columellae distinct and thicker nexine (0.6 µm).

Ladakhipollenites rectangularis n. sp. Plate 5, Figs. 7, 8, 9, 10

Diagnosis: Tricolpate, rectangular, mid-sized (25-26 µm), colpi mid-sized, simple, psilate, tectate. Specimens: Holotype AM27-21, EF: T 23 2 pl. 5, figs. 7,8; paratypes AM27- 21, EF: L33 2 and AM27-19, EF: X 37 1 pl. 5, figs 9,10 Type locality: Well 1AS-27-AM Etymology: After the grain shape Description: Monad, radial, isopolar, rectangular; tricolpate, colpi mid-sized, colpi 17 µm long, CPi 0.68, simple, borders slightly convex, ends pointed; tectate, exine 1.2 µm thick, nexine 0.2 µm thick, columellae 0.8 µm thick, distinct, tectum 0.2 µm thick; sculpture psilate, few microechinae scattered over entire grain, <0.4 µm wide and high, tips are visible, <0.3 µm wide. Dimensions: equatorial length 25 (25.5) 26 µm, SD 0.7; equatorial width 17 (17.5) 18 µm, SD 0.7; equatorial diameter length/width 1.5, n=2. Comparisons: Ladakhipollenites floratus n. sp. has colpi long and is psilate. Psilatricolpites polaroides Gonzalez, 1967 has exine thicker in the polar area (4 µm).

Genus Lakiapollis Venkatachala&Kar, 1969

Lakiapollis costatus n. sp. Plate 5, Figs. 20, 21

Diagnosis: Tricolporate, triangular-obtuse-convex, mid-sized (17 µm), colpi marginate and costate, psilate, tectate, columellae indistinct, tectum thick. Specimens: Holotype AM27-28, EF: M54 2 pl. 5, figs. 20, 21; paratype AM27- 27, EF: Q56 2 Type locality: Well 1AS-27-AM Etymology: After the costae of the colpi. Description: Monad, radial, isopolar, triangular-obtuse-convex; tricolporate, colpi short, 12 µm long, CEi 0.6, marginate, margo 2 µm wide, produced by thinning of the nexine near to colpi, segmented, is not present in equatorial area, colpi costate, costae 2 µm wide, 1 µm thick, distinct, absence of the equatorial area, borders straight, ends rounded, colpi length 12 µm, pores simple 4 µm wide, 2 µm high, lalongate, fastigiate; tectate, exine 2 µm thick, nexine 1.5 µm thick, thick nexine, nexine decreases towards colpi, columellae absent, tectum 0.5 µm thick; sculpture psilate. Dimensions: equatorial length 17 µm; equatorial width 18 (19) 20 µm, SD 1.4; equatorial diameter length/width 0.9, n=2. Comparisons: Lakiapollis Venkatachala&Kar, 1969 accommodates brevicolpate, psilate or micropitted grains. Lakiapollis aff. ovatus Venkatachala&Kar, 1969 has pores costate. Psilatricolporites costatus Dueñas, 1980 has columellae distinct, colpi is not marginate. Psilatricolporites marginatus Van der Kaars, 1983 colpi is not costate. Retitricolporites ticuneorum Hoorn, 1993 is micropitted and colpi is not costate.

Genus Loranthacites Mchedlishvili in Samoilovitch&Mchedlishvili, 1961

Loranthacites psilatus n. sp. Plate 5, Figs. 16, 17

Diagnosis: Tricolpate, triangular-acute-straight, mid-sized (38 µm), psilate, tectate, columellae digitate, colpi marginate. Specimens: Holotype AM27-5, EF: M67 1 pl. 5, Figs. 16, 17 Etymology: After the colpi shape. Description: Monad, radial, triangular-acute-straight; tricolpate, colpi very long, 38 µm long, CEi 1, marginate, margo 3 µm wide, produced by a thinning of the columellae; tectate, exine 2 µm thick, nexine 0.2 µm thick, columellae 1.6 µm high, 0.5 µm wide, longitudinal distribution of the columellae resembling a striate pattern, digitate, tectum 0.2 µm, near to colpi columellae disappear where the tectum/sexine seems the same layer; sculpture psilate. Dimensions: equatorial length 26 (34) 38 µm; equatorial width 30 (33.6) 37 µm; equatorial diameter length/width 1, n=5. Comparisons: Loranthacites macrosolenoides Samoilovitch&Mchedlishvili, 1961 has reticulate/striate sculpture. Gothanipollis perplexus Pocknall&Mildenhall, 1984 has sexine psilate at the apices varying from scabrate to granulate in interapical areas.

Loranthacites sp. 1 Plate 5, Figs. 18, 19

Diagnosis: Syncolpate, triangular-acute-concave, mid-sized (28 µm), psilate, tectate, with apocolpia field. Specimens: AM27-9, EF: R 37 2, pl. 5 figs. 18,19 Description: Monad, radial, triangular-acute- concave; syncopate, apocolpia filed is present, darker area in the apocolpia, borders straight, ends pointed; tectate, exine 1 µm thick, nexine 0.3 µm thick, columellae 0.4 µm high, distinct, 0.5 µm apart, tectum 0.3 µm; sculpture psilate. Dimensions: equatorial length 25 (28.2) 31 µm; equatorial width 22 (30.8) 35 µm; equatorial diameter length/width 1, n=4. Comparisons: Loranthacites psilatus n. sp. has no apocolpia field, has colpi marginate and columellae digitate.

Genus Malvacipolloides Anzotegui&Garalla, 1985/86

Malvacipolloides maristellae MULLER, ET AL., 1987 n. comb. Plate 5, Figs. 25, 26

1986 Echitricolporites maristellae Lorente, p.190, pl. 19, figs. 2 and 3 1987 Echitricolporites maristellae Muller et al. p. 48, pl. 4, figs.11 and12

Diagnosis: Tricolporate, circular, mid-sized (30-39 µm), pores lalongate, echinate, tectate, prominent spines present on the pores. Specimens: AM27-2, EF: V38 ¾ pl. 5, figs. 25, 26 Description: Monad, radial, isopolar, circular; tricolporate, colpi short, 10 µm long, CEi 0.26, simple, almost indistinct, pores 1 µm wide, 2-3 µm long, costate, costae well developed, 3 µm wide, 2 µm thick; tectate, thin exine, exine 1 µm thick, nexine 0.5 µm thick, columellae 0.5 µm thick, distinct, tectum 0.5 µm thick, exine increasing to 2 µm thick towards spines base; sculpture echinate, spinae 2-3 µm long, 3 µm wide, 3-5 µm apart, conical, spinae higher near to aperture, reaching 4 µm long, the exine is denser and darker at the base of the spines, interechinae surface micropitted. Dimensions: equatorial length 30 (35.7) 39 µm, SD 4.9; equatorial width 28 (36.3) 42, SD 7.4; equatorial diameter length/width 1, n=3. Comparisons: Echitricolporites Van der Hammen, 1956 Germeraad, et al., 1968 is invalidate name because was based on recent pollen of Baccharis tricuneata (L.f). Germeraad, et al., 1968 tried validate Echitricolporites but also was an illegitimate name because designated a fossil species as type species as proposed by Van der Hammen, 1956. Malvacipolloides ANZOTEGUI&GARALLA, 1985/86 accommodates tricolporate, tectate and echinate grains.

Malvacipolloides sp. 1 Plate 5, Figs. 22, 23, 24

Diagnosis: Brevitricolporate, circular, mid-sized (27 µm), pores lalongate, echinate, tectate. Specimens: AM19-3, EF: U29 2/4 pl. 5, figs. 22, 23, 24 Description: Monad, radial, isopolar, circular; tricolporate, colpi short, 10 µm long, CEi 0.37, borders straight, ends rounded, slightly costate, costae 2 µm wide, 0.5 µm thick, pores simple, pores 2 µm wide, 1 µm high, lalongate, indistinct; tectate, exine 1.5 µm thick, nexine 0.3 µm thick, columellae 0.9 µm thick, distinct, tectum 0.3 µm thick; sculpture echinate, spinae 3 µm long, 2 µm wide, 2-3 µm apart, conical in plain view, interspines surface micropitted. Dimensions: equatorial length 27 µm; equatorial width 26 µm; equatorial diameter length/width 1, n=1. Comparisons: Malvacipolloides maristellae Muller, et al., 1987 n. comb. has spines protruding near to aperture. Echiperiporites estelae (Germeraad et al. 1968) is periporate.

Malvacipolloides sp. 2 Plate 5, Figs. 27, 28

Diagnosis: Tricolporate, triangular-obtuse-convex, mid-sized (38 µm), echinate, tectate. Specimens: AM27-21, EF: X41 2 pl. 5, figs. 27, 28 Description: Monad, radial, isopolar, triangular-obtuse-convex; tricolporate, colpi long, 20 µm long, CEi 0.6, simple, pores indistinct; tectate, exine 1.5 µm thick, nexine 0.4 µm thick, columellae 0.9 µm thick, very thin, dense, 0.1 µm apart, densely packed, tectum 0.2 µm thick; sculpture echinate, spines 3-5 µm high, 2-3 µm wide, 3 µm apart, spines are cylindrical of the base, 4µm wide, tapered at the apices, 1 µm high, interspines region is micropitted, lumina <0.5 wide. Dimensions: equatorial length 33 µm; equatorial width 33 µm; equatorial diameter length/width 1, n=1. Comparisons: Brevitricolporites macroexinatus Jaramillo&Dilcher, 2001 has endopores costatus. Brevitricolporites microechinatus Jaramillo&Dilcher, 2001 has pores annulate.

Malvacipolloides? sp. 3 Plate 5, Figs. 43, 44

Diagnosis: Tricolporate, circular, prolate, mid-sized (32 µm), microechinate, tectate. Specimens: AM27-22, EF: Y70 1 pl. 5, figs. 43, 44 Description: Monad, radial, isopolar, circular, prolate; tricolporate, colpi long, colpi 16 µm long, CEi 0.5, simple, borders straight, ends pointed, endopores simple, lalongate; tectate, exine 0.8 µm thick, nexine 0.2 µm thick, columellae 0.4 µm thick, indistinct, tectum 0.2 µm thick, sculpture microechinate, <0.5 µm high and wide, well distributed, 1 µm apart, interspines region is psilate. Dimensions: equatorial length 32 µm, equatorial width 28 µm, equatorial diameter length/width 1.1, n=1. Comparisons: Brevitricolpites microechinatus Jaramillo&Dilcher, 2001 is intectate, Brevitricolpites variabilis Gonzalez, 1967 is clavate to gemmate.

Genus Margocolporites Ramanujam, 1966 ex Srivastava, 1969 emend. Pocknall&Mildenhall, 1984

Margocolporites fastigiatus n. sp. Plate 5, Figs. 33, 34, 35, 36

Diagnosis: Margotricolporate, circular, mid-sized (22-26µm), colpi marginate, pores indistinct, psilate, micropitted-scabrate, tectate (ENGLOBAR PSILATE- MICROP). Specimens: Holotype, EF: AM27-30 V31 2 pl. 5, figs. 33, 34; paratype: AM27- 30, EF: U 32 4, AM27-22, EF: X54 2 pl. 5, figs. 35, 36; Etymology: After the presence of the fastigium Type locality: Well 1AS-27-AM Description: Monad, radial, isopolar, small polar area 6 µm, circular; tricolporate, colpi mid-sized, colpi 14 µm long, CEi 0.6, ectocolpi marginate, margo 2 µm wide, margo produced by a thinning of the exine to 1 µm around the colpi, borders straight, ends pointed, endopores simple, fastigiate, 8 µm wide, 2 µm high, lalongate; tectate, exine 1.5 µm thick, nexine 0.5 µm thick, columellae indistinct, columellae disappear near to colpi, tectum 1 µm thick; sculpture micropitted, lumina <0.5 µm wide, circular, heterobrochate, lumina decreases towards colpi becoming the margo psilate. Dimensions: Polar diameter 28 µm, equatorial diameter 22 µm, polar/equatorial 1.3, n=1; Equatorial length 22 (25.2) 28 µm, SD 2.2, equatorial width 17 (24.2) 27 µm, SD 4.1, equatorial diameter length/width 1, n=5. Comparisons: Siltaria hammeni n. sp. has colpi costate.

Margocolporites pseudodemicolpatus n. sp. Plate 5, Figs. 39, 40

Diagnosis: Brevitricolporate, triangular-obtuse-straight, mid-sized (28-36µ), psilate, atectate, colpi is surrounded by a thinning of the exine. Specimens: Holotype AM27-26, EF: G38 1/3 pl. 5, figs. 39, 40; paratype: AM27-26, EF: D59 1 Type locality: Well 1AS-27-AM Etymology: After the pseudo shape of the colpi Description: Monad, radial, isopolar, triangular-obtuse-straight; tricolporate, colpi costate, costae 2 µm wide, 2 µm thick, borders straight, ends pointed, colpi 10 µm long, CEi 0.28, endopores costate, costae 2 µm thick, pores 2 µm wide, 1 µm high, lalongate; atectate, exine 1 µm thick, the grain shows a unusually thinner of the exine in the interangular area, the exine becomes thin between the colpi in the semi angular area, there are two thin of the exine 1) between each colpi, the thinner in the apocolpia area produced a feature resembling a apocolpia field, 2) 2 endocolpi surrounding each brevicolpi; sculpture psilate. Dimensions: Equatorial length 28 (32.8) 36 µm, SD 3.6, equatorial width 28 (34) 49 µm, SD 5, equatorial diameter length/width 1, n=4. Comparisons: Margocolporites Ramanujam, 1966 ex Srivastava, 1969 emend. Pocknall&Mildenhall, 1984 accommodates Margocolporate grains from psilate to reticulate sculpture. Psilate grains have not been reported in any species of Margocolporites, may be this specimen is the same specimen Margocolporites rauvolfii described by Salard-Cheboldaeff, 1978. Similar to Ctenolophonidites Van Hoeken-Klinkenberg, 1966 but this genus is characterized by a thickening of the exine. Margocolporites scabratus Pocknall&Mildenhall, 1984 is psilate to scabrate and amb roundly triangular. Natural affinities: Raufolvia, Apocynaceae.

Margocolporites sp. 1 Plate 5, Figs. 41, 42

Diagnosis: Tricolpate, circular, mid-sized (28 µm), reticulate, heterobrochate, semitectate, colpi marginate Specimens: AM27-26, EF: H56 4 pl. 5, figs. 41, and 42 Description: Monad, radial, circular; tricolpate, colpi long, marginate, margo 4 µm wide, produced by a decreasing of the reticulum, borders straight, ends pointed, colpi 26 µm long; semitectate, exine 1 µm thick, nexine 0.3 µm thick, columellae 0.5 µm high, distinct, tectum 0.2 µm thick; sculpture reticulate, heterobrochate, lumina gradually decreasing from interangular area to colpi, 0.5-2.0 µm wide, elongated, muri 0.5 µm wide, pluricolumellate. Dimensions: equatorial length 28 µm, equatorial width 28, equatorial diameter length/width 1, n=1. Comparisons: Margocolporites vanwijhei GERMERAAD, ET AL., 1968 has colpi costate and marginate.

Genus Meliapollis Sah&Kar, 1970

Meliapollis? sp. 1 Plate 5, Figs. 29, 30

Diagnosis: Stephanocolporate, circular to quadrangular, mid-sized (22 µm), psilate, atectate. Specimens: AM27-27, EF: M60 4/3 pl. 5, figs. 29, 30 Description: Monad, radial, isopolar, circular to quadrangular; stephanocolporate, colpi simple, 5-colporate, colpi mid-sized, colpi 12 µm long, CEi 0.54, borders straight, ends rounded, large polar area of 12 µm wide, pores costate, costae 1 µm thick, pores 1 µm wide, pores 1 µm high, circular; atectate, exine 1 µm thick; sculpture psilate. Dimensions: equatorial length 22 µm, equatorial width 22 µm, equatorial diameter length/width 1.1, n=1. Comparisons: Tetracolporites Couper, 1953 emend. Pocknall&Mildenhall, 1984 has spherical to polygonal shape and colpi indistinct Jansonius&Hills, 1976 card 4348. Psilastephanocolporites Leidelmeyer, 1966 has 8-10 furrows and pores Jansonius&Hills, 1976 card 2229). Meliapollis Sah&Kar, 1970 accommodates grains with colpi simple, pores costate, psilate and tectate. Here, we accept this genus despite of the grain is atectate. Tetracolporites psilatus Jaramillo&Dilcher, 2001 has ectocolpi marginate, is tectate, larger (30-50 µm). Psilastephanocolporites variabilis (Regali et al., 1974) has colpi costate. Psilastephanocolporites globulus Van Hoeken-Klinkenberg, 1966 has colpi costate, is smaller (16 µm) and is intectate.

Genus Monocolpopollenites Pflug&Thomson, 1953 in Thomson&Pflug, 1953 emend. Nichols, et al., 1973

Monocolpopollenites sp. 1 Plate 5, Figs. 37, 38

Diagnosis: monocolpate, circular, mid-sized (22 µm), micropitted, tectate, colpi short, flared. Specimens: AM27-33, EF: O27 4 pl. 5, figs. 37, 38 Description: Monad, bilateral, isopolar, circular; monocolpate, colpi short, colpi 16 µm long, CEi 0.72, ends flared, borders straight; tectate, exine 0.5 µm thick; sculpture micropitted, lumina < 0.5 µm. Dimensions: polar diameter 22 µm, equatorial diameter 22 µm, polar/equatorial 1, n=1. Comparisons: Monocolpopollenites ovatus (Jaramillo & Dilcher, 2001) is larger (32-60µm). Arecipites polaris n. sp. is prolate and colpi pointed.

Genus Multiporopollenites Pflug&Thomson, 1953 in Thomson&Pflug, 1953

Multiporopollenites crassinexinatus n. sp. Plate 6, Figs. 1, 2

Diagnosis: Pantoporate, circular, mid-sized (23 µm), pores irregular, micropitted, tectate, nexine very thick. Specimens: Holotype AM27-23, EF: N40 3 pl. 6, figs. 1, 2 Type locality: Well 1AS-27-AM Description: Monad, radial, isopolar, circular; pantoporate, ecto/endopores coinciding, pores 1 µm wide, pores 1 µm long, circular to elongated, 24 pores are presents; tectate, exine 3 µm thick, nexine very thick, 2 µm thick, columellae 0.8 µm thick, distinct, 0.5 µm wide, 0.5 µm apart, tectum 0.2 µm thick; sculpture micropitted, lumina 0.5 µm wide, circular, homobrochate, densely distributed, muri 0.5 µm wide. Dimensions: equatorial length 23 µm; equatorial width 22 µm; equatorial diameter length/width 1, n=1. Comparisons: Psilaperiporites minimus REGALI, ET AL., 1974 is psilate and has more pores (40-50 pores). Multiporopollenites pauciporatus JARAMILLO&DILCHER, 2001 has pores annulate. Psilaperiporites robustus (Regali et al. 1974) has 80 pores.

Genus Paleosantalaceapites Biswas 1962 ex Dutta & Sah (1970)

Paleosantalaceapites sp. 1 Plate 6, Figs. 3, 4

Diagnosis: Tricolporate, prolate, mid-sized (24-35 µm), foveolate, tectate, zonasulcate. Specimens: Holotype AM27-18, EF: T41 3 pl. 6, figs. 3, 4 Description: Monad, radial, isopolar, area polar rounded, prolate; tricolporate, colpi long, costate, costae 2 µm wide, 1 µm thick, borders straight, ends indistinct, colpi 18 µm long, CPi 0.75, zonosulculate, simple 4 µm high; tectate, exine 1.2 µm thick, nexine 0.5 µm thick, columellae 0.5 µm high, 0.5 µm apart, distinct, tectum 0.2 µm thick; sculpture foveolate, lumina 0.5 µm wide, circular, muri 1 µm wide. Dimensions: Polar diameter 24 (29.6) 37 µm, SD 5.1, equatorial diameter 15 (17.1) 23 µm, SD 3.0, Polar/equatorial 1.7, n=7. Comparisons: Paleosantalaceapites Biswas 1962 ex Dutta & Sah (1970) accommodates tricolporate, longi or brevicolpate, zonosulculate pollen grains. Paleosantalaceaepites distinctus (Jaramillo & Dilcher, 2001) has lumina decreasing from pole to equator.

Genus Parsonsidites Couper 1960

Parsonsidites? brenacii n. sp. Plate 6, Figs. 5, 6

Diagnosis: Pantoporate, mid-sized (16-21 µm), circular, psilate, tectate, 10 pores, thick tectum. Specimens: Holotype AM27-20, EF: S37 3 pl. 6, figs. 5, 6 Type locality: Well 1AS-27-AM Etymology: In honor to Patrick Brenac Description: Monad, radial, isopolar, circular; pantoporate, pores simple, 10 pores are present, pores 2 µm wide, pores 2 µm high, circular; tectate, exine 3 µm thick, nexine 0.5 µm thick, columellae 2 µm thick, distinct, 0.5 µm wide, 0.5-1 apart, tectum very thin, 0.5 µm thick; sculpture psilate, he tips of the columellae are highly visible. Dimensions: equatorial length 16 (18.7) 21 µm, SD 2.5; equatorial width 17 (19.3) 21 µm, SD 2.1; equatorial diameter length/width 1, n=3. Comparisons: Multiporopollenites pauciporatus Jaramillo&Dilcher, 2001 is micropitted.

Genus Proxapertites Van der Hammen, 1956

Proxapertites tertiaria Van der Hammen & Garcia 1966 Plate 6, Fig. 16

1987 Proxapertites magnus Muller et al., p. 37, Pl. 1, Fig. 11. 2001 Proxapertites magnus Jaramillo & Dilcher, p. 141, Pl. 14, Figs. 10, 11.

Diagnosis: zonosulcate, circular, big-sized (90 µm), foveolate, tectate. Specimens: AM27-3, EF: R42 4 pl. 6, Fig. 16 Description: Monad, radial, anisopolar, triangular to circular, sulcus dividing the grain in two unequal parts; zonosulcate; tectate, exine 3 µm thick, nexine 1 µm thick, columellae 1 µm high, tips very discernible, thick tectum, tectum 1 µm thick; sculpture foveolate, foveos 0.5 µm wide, distributed uniformly for whole grain. Dimensions: equatorial length 90 µm, equatorial width 82 µm, equatorial diameter length/width 1.1, n=1. Comparisons: The difference between Proxapertites tertiaria (Van der Hammen & Garcia, 1966) and Proxapertites magnus (Muller et al., 1987) is based on size of the grain. However, intermediate sizes also were observed.

Genus Psilabrevicolpites van Hoeken-Klinkenberg, 1966

Psilabrevicolpites flexibilis van Hoeken-Klinkenberg, 1966 Plate 6, Figs. 11, 12, 13

Diagnosis: Tricolpate, brevicolpate, triangular-obtuse-concave, mid-sized (18 µm), psilate, tectate, colpi simple. Specimens: AM27-28, EF: P28 1/2 pl. 6, figs. 11, 12, 13 Description: Monad, radial, isopolar, triangular-obtuse-concave; tricolpate, colpi simple, brevicolpate, colpi 6 µm long, CEi 0.3, borders straight, ends ragged irregular; tectate, exine 1.2 µm thick, nexine 0.3 µm thick, columellae 0.2 µm high, indistinct, tectum 0.7 µm thick, exine thickness uniform; sculpture psilate. Dimensions: Equatorial length 18 µm, equatorial width 19 µm, equatorial diameter 0.9, n=1.

Genus Psilabrevitricolporites Van der Kaars, 1983

Psilabrevitricolporites devriesi Lorente 1986 n. comb. Plate 6, Figs. 7, 8, 9, 10

1986 Psilatricolporites devriesi Lorente et al. p.197, pl. 21, figs 1,2

Diagnosis: Tricolporate, brevicolpate, circular, mid-sized (22 µm), psilate, tectate, colpi simple, colpi costate, thick exine. Specimens: AM27-31, EF: X30 4 pl. 6, Figs. 7, 8, 9, 10 Biochronological range: UA 1 Description: Monad, radial, circular to triangular-obtuse-convex, oblate; tricolporate, colpi costate, costae 2 µm wide, 2 µm thick, brevicolpi 10 µm long, CEI, CPi borders straight, ends pointed, pores simple, pores 3 µm wide, pore 3 µm high, circular; tectate, thick exine, exine 3 µm thick, sexine 1 µm thick, columellae 1 µm high, distinct, tectum µm thick; sculpture psilate. Dimensions: equatorial length 22 (22.5) 23 µm, SD 0.7; equatorial width 21 µm, equatorial diameter length/width 1.1, n=2; polar diameter 30 µm, equatorial diameter 25 µm, polar/equatorial 1.2, n=1.

Psilabrevitricolporites sp. 1 Plate 6, Figs. 14, 15

Diagnosis: Tricolporate, circular, mid-sized (29 µm), psilate, tectate, pores annulate. Specimens: AM27-18, EF: R 25 4 pl. 6, figs. 14, 15 Type locality: Well 1AS-27-AM Description: Monad, radial, isopolar, circular; brevicolporate, colpi 10 µm long, CEi 0.34, slightly marginate, 1 µm wide, margo produced by a thinning of the exine, pores costate, 1 µm wide, 1 µm thick, pores 2.5 µm wide, pores 2.2 µm high, circular; tectate, exine 1 µm thick, nexine 0.2 µm thick, columellae 0.6 µm thick, indistinct, columellae decreasing towards pores, tectum 0.2 µm thick; sculpture psilate. Dimensions: equatorial length 29 µm; equatorial width 26 µm; equatorial diameter length/width 1.1, n=1. Comparisons: Psilabrevitricolporites devriesi Lorente, 1986 n. comb. has pores costate and exine thicker (2 µm). Siltaria mariposa Leidelmeyer, 1966 Jaramillo and Dilcher, 2001 has longer colpi.

Genus Psilaperiporites Regali et al. 1974

Psilaperiporites sp. 1 Plate 6, Figs. 24, 25

Diagnosis: Pantoporate, circular, mid-sized (30 µm), pores costate, psilate, tectate, 18 pores. Specimens: Holotype 27-38, EF: W21 4/3 pl. 6, Figs. 24, 25 Description: Monad, radial, isopolar, circular; pantoporate, pores slightly annulate, annulus 2 µm wide, highly distinct, 18 pores arranged in pairs, each pores on each hemisphere is facing the another one, pores simple, pores 3 µm high, pores 3 µm wide, 7 µm apart, circular; atectate, exine 0.5 µm thick; sculpture psilate. Dimensions: equatorial length 30 µm; equatorial width 25 µm; equatorial diameter length/width 1.2, n=1. Comparisons: Psilaperiporites multiporus Hoorn, 1994 has pores that are not arranged in pairs. Psilaperiporites robustus Regali, et al., 1974 has more pores (60-64 pores).

Genus Psilastephanoporites Regali, et al., 1974 ex Hoorn, 1993

Psilastephanoporites herngreenii Hoorn 1993 Plate 6, Figs. 17, 18

Diagnosis: Stephanoporate, circular to quadrangular, mid-sized (µm), psilate, atectate. Specimens: AM27-27, EF: S55 1 pl. 6, figs. 17, 18 Description: Monad, radial, isopolar, circular to quadrangular; stephanoporate, pores 7 µm wide, pores 7 µm long, circular, 4 pores costate, costae 5 µm wide, 2 µm thick, protruding, granulate at the pores base; atectate, exine 0.5- 1 µm thick, increasing to 4 µm near to pores; sculpture psilate. Dimensions: equatorial length 45 µm; equatorial width 40; equatorial diameter length/width 1.1, n=1.

Psilastephanoporites sp. 1 Plate 6, Figs. 26, 27, 28

Diagnosis: Stephanoporate, circular, mid-sized (22-31 µm), psilate, atectate. Specimens: AM27-26, EF: E46 2 pl. 6, figs 26, 27, 28 Description: Monad, radial, isopolar, circular; stephanoporate, pores 3 µm wide, pores 3 µm long, circular, 4 pores annulate, annulus 2.5 µm wide, 2 µm thick, protruding, slightly granulate at the base; atectate, exine 0.5 µm thick; sculpture psilate. Dimensions: equatorial length 22 (26.5) 31 µm, SD 6.4; equatorial width 30 (33.5) 37 µm, SD 4.9; equatorial diameter length/width 0.8, n=2. Comparisons Psilastephanoporites herngreenii Hoorn, 1993 has annuli of 8 µm thick. Psilastephanoporites stellatus Regali, et al., 1974 has 6 pores and exine thicker.

Genus Retibrevitricolpites Van Hoeken-Klinkenberg, 1966

Retibrevitricolpites sp. 1 Plate 6, Figs. 19, 20

Diagnosis: Tricolporate, circular, mid-sized (23 µm), micropitted, tectate. Specimens: AM27-24, EF: D45 4 pl. 6, figs. 19, 20 Description: Monad, radial, isopolar, circular; tricolporate, colpi short, simple, borders straight, ends pointed, colpi 6 µm long, CEi 0.26, pores indistinct; tectate, exine 1.0 µm thick, nexine 0.3 µm thick, columellae 0.4 µm thick, indistinct, tectum 0.3 µm thick; sculpture micropitted, densely distributed, 0.5 µm wide, 0.5 µm apart. Dimensions: equatorial length 23 µm, equatorial width 20 µm, equatorial diameter length/width 1.2, n=1. Comparisons: Retibrevitricolpites retibolus Leidelmeyer, 1966 and Psilabrevicolporites sp. 1 (Jaramillo and Dilcher, 2001) have pores costate.

Genus Retibrevitricolporites Legoux 1978

Retibrevitricolporites yavarensis Hoorn 1993 n. comb. Plate 6, Figs. 34, 35, 36, 37

1993 Retibrevitricolpites yavarensis Hoorn 1993

Diagnosis: Tricolporate, circular, mid-sized (20 µm), micropitted, tectate, brevicolpate, colpi costate, pores simple. Specimens: AM27-28, EF: T48 4 pl. 6, Figs. 34, 35, tetracolporate: AM27-23, EF: T34 4, pl. 6, Figs. 36, 37 Description: Monad, radial, circular; tricolporate, colpi very short, colpi 10 µm long, CEi 0.5, borders straight, ends pointed, colpi costate, costae 1.5 µm wide, pores simple, lalongate, indistinct; tectate, exine 1 µm thick, nexine 0.3 µm thick, columellae 0.5 µm high, 0.5 µm apart, distinct, tectum 0.2 µm thick; sculpture micropitted, lumina 0.5 µm wide, circular to elongate, homobrochate, muri 0.5 µm wide. Dimensions: Equatorial length 20 µm, equatorial width 20 µm, equatorial diameter 1, n=1. Comparisons: The species was firstly described as tricolpate, but we saw the holotype and it is tricolporate. Grain tetracolporate also were found.

Genus Retistephanocolpites Leidelmeyer, 1966 emend. Saxena, 1982

Retistephanocolpites circularis n. sp. Plate 6, Figs. 31, 32, 33

Diagnosis: Stephanocolpate, circular, mid-sized (23-24 µm), reticulate, tectate, 5 colpi, brevicolpate, colpi marginate, homobrochate. Specimens: Holotype AM27-27, EF: G57 1/2 pl. 6, figs. 31, 32, 33, paratype AM27-20, EF: W24 3 Type locality: Well 1AS-27-AM Etymology: After the circular shape of the grain. Description: Monad, radial, isopolar, circular; stephanocolpate, 5 colpi, colpi marginate, margo produced by a thinning of the exine, 2 µm wide, brevicolpate, colpi 8 µm long, CEi 0.26, borders straight, ends rounded; tectate, exine 2 µm thick, nexine 0.5 µm thick, columellae 1 µm high, distinct, 0.5 µm thick, 1 µm apart, columellae decreases towards colpi, tectum 0.5 µm thick; sculpture reticulate, lumina 0.5 µm wide, homobrochate, circular to elongated, muri 0.5 µm wide. Dimensions: equatorial length 30 (32) 34 µm, SD 2.8, equatorial width 25 (28) 31 µm, SD 4.2, polar/equatorial 1.2, n=2. Comparisons: Retistephanocolpites Leidelmeyer, 1966 emend. Saxena, 1982 accommodates stephanocolpate grains with reticulate, foveoreticulate or foveolate sculpture JANSONIUS&HILLS, 1976 card 4149. Retistephanocolpites gracilis (Regali et al., 1974) has 6-8 colpi and colpi shorter.

Genus Retistephanocolporites Van der Hammen & Wymstra 1964

Retistephanocolporites sp. 1 Plate 6, Figs. 21, 22, 23

Diagnosis: Stephanocolporate, prolate, mid-sized (19µm), micropitted, tectate, colpi costate pores simple. Specimens: AM27-7, EF: U24 2 pl. 6, figs. 21, 22, 23 Description: Monad, radial, isopolar, prolate; stephanocolporate, colpi mid- sized, colpi 14 µm long, CPi 0.73, colpi costate, costae 1 µm thick, decreasing from mesocolpia to apocolpia, borders straight, ends pointed, endopores simple, pores 2 µm wide, pores 3 µm long, lolongate; tectate, exine 2 µm thick, nexine 1 µm thick, columellae 0.5 µm high, distinct, tectum 0.5 µm thick; sculpture micropitted, lumina 0.5 µm, homobrochate, circular, densely distributed over entire grain, muri <0.2 µm wide. Dimensions: polar diameter 19 µm, equatorial diameter 14 µm, polar/equatorial 1.4, n=1. Comparisons: Retistephanocolporites festivus Gonzalez, 1967 is larger (26-50 µm).

Genus Retitrescolpites Sah, 1967

Retitrescolpites? traversei n. sp. Plate 6, Figs. 40, 41, 42, 43, 44

Diagnosis: Tricolporate, prolate, mid-sized (26-30µm), reticulate, heterobrochate, simplicolumellate, semitectate, pores operculate. Specimens: Holotype AM27-24, EF: J60 4 pl. 6, figs. 184, 185 and 186; paratype AM27-21, EF: U26 1 pl. 6, figs. 40, 41 Type locality: Well 1AS-27-AM Etymology: After the reticulum shape. Description: Monad, radial, prolate; tricolporate, colpi long, colpi 22 µm long, CPi 0.73, borders straight, ends pointed, marginate, margo 3 µm wide, margo produced by a drastic decreasing of the reticulum, pores simple, pores 2 µm wide, pores 2 µm long, circular, operculate, operculum 1 µm wide, 1 µm long; semitectate, exine 3.5 µm thick, nexine 1.5 µm thick, increasing to 1 µm towards apocolpia area, columellae 1.5 µm high, distinct, tectum 0.5 µm thick, restricted to columellae; sculpture reticulate, lumina 4-7 µm wide, polygonal, simplicolumellate, heterobrochate, abruptly decreasing around colpi to 1 µm, muri 1 µm wide. Dimensions: polar diameter 26 (28) 30 µm, equatorial diameter 18 (19) 20 µm polar/equatorial 1.5, n=2. Comparisons: Retitrescolpites Sah, 1967 accommodates tricolpate-colporate coarsely reticulate grains. Retitrescolpites magnus Gonzalez, 1967 Jaramillo&Dilcher, 2001 has regular lumina. Natural affinity: Teliostachya, Acanthaceae

Retitrescolpites? sp. 1 Plate 6, Figs. 38, 39

Diagnosis: Tricolporate, circular, mid-sized (27 µm), coarsely reticulate, semitectate and pores costate. Specimens: 19-2, EF: N51 2/1 pl. 6, figs. 38, 39 Description: Monad, radial, circular; tricolporate, colpi long, simple, borders straight, ends pointed, colpi intruding, small polar area, 7 µm wide, colpi 10 µm long, CEi 0.37, pores costate, costae 2 µm wide, 2 µm thick, pores 2 µm wide, pores 2 µm long, circular; semitectate, exine 4 µm thick, nexine 0.4 µm thick, columellae 2.8 µm high, distinct, tectum 0.8 µm thick, decreasing to 2 µm towards aperture produced by decreasing of the columellae; sculpture reticulate, heterobrochate, lumina of the mesocolpia 3 µm wide, elongated to polygonal, decreasing gradually towards apocolpia where becomes micropitted, muri 1.5 µm wide, curvimurate, pluricolumellate. Dimensions: equatorial length 27 µm, equatorial width 26 µm, polar/equatorial 1, n=1. Comparisons: Bombacacidites sp. 3 (Jaramillo and Dilcher, 2001) has pores lalongate and foveoreticulate. Retibrevitricolpites retibolus Leidelmeyer, 1966 is brevicolpate. Retitrescolpites? irregularis (Van der Hammen and Wymstra, 1964) Jaramillo and Dilcher, 2001 is homobrochate.

Retitrescolpites sp. 2 Plate 6, Figs. 29, 30

Diagnosis: tricolpate, triangular-obtuse-convex, mid-sized (18-24 µm), reticulate, semitectate, folded at the poles, resembling a trilete mark. Specimens: 27-58, EF: V21 1/2 pl. 6, Figs. 29, 30, 27-92, EF: X63 2 Biochronological range: from UA 1 to UA 7. Description: Monad, radial, isopolar, triangular-obtuse-convex; tricolpate, colpi marginate, margo 2 µm wide, margo produced by decreasing of the lumina, borders straight, ends pointed, colpi 8 µm long; semitectate, exine 1.2 µm thick, nexine 0.2 µm thick, columellae 0.8 µm thick, tectum 0.2 µm thick; sculpture reticulate, almost foveolate near to colpi, lumina 2 µm wide, lumina irregular decreasing towards colpi, muri <0.5 µm wide. Dimensions: equatorial length 18 (21) 24 µm, SD 3, equatorial width 12 (16.3) 22 µm, SD 5.1, equatorial diameter length/width 1.3, n=3. Comparisons: Retitricolpites marginatus Van Hoeken-Klinkenberg, 1966 has lumina wider (3.5 µm), exine thicker (2.5µm) and larger (32 µm).

Genus Retitriporites Ramanujam, 1966

Retitriporites rotundus n. sp. Plate 6, Figs. 45, 46, 47, 48

Diagnosis: Triporate, triangular-obtuse-convex, mid-sized (26-27µm), foveoreticulate, tectate, pores marginate and large. Specimens: Holotype 27-22, EF: P52 ½ pl. 6, figs. 47, 48; paratypes: 27-20, EF: U24 4, 27-18, EF: N40 ½ pl. 6, figs. 45, 46 Type locality: Well 1AS-27-AM Etymology: After the grain shape. Description: Monad, radial, isopolar, triangular-obtuse-convex; triporate, ectopores and endopores coinciding, 10 µm wide, 3 µm long, marginate, margo 3 µm wide, produced by decreased of lumina towards pores, pores circular, pores 9 µm wide; tectate, exine 1-2 µm thick, exine 2 layered, inner part 0.6-1.5 µm thick, straight, outer 0.5 µm thick, lighter color, columellae is not present, tectum is present only in the muri of the reticulum; sculpture foveo-reticulate, lumina decreasing towards pores, heterobrochate, 2-3 µm wide, muri is reticulate with small lumina arranged in line parallels to the borders of the muri, 1-2 µm wide, well distinct. Dimensions: equatorial length 20 (24.8) 27 µm, SD 3.2; equatorial width 20 (26) 29 µm, SD 4.2; equatorial diameter length/width 1.0, n=4. Comparisons: Retitriporites tilburgii Gonzalez, 1967 has lumina smaller (0.7 µm). Variation: grains with triangular-acute-straight shape also were found.

Retitriporites sp. 1 Plate 7, Figs. 1, 2

Diagnosis: Triporate, triangular-obtuse-convex, mid-sized (28 µm), reticulate, semitectate, endopores costate, muri curvimurate. Specimens: 27-75, EF: K49 4/3 pl. 7, figs. 1, 2 Description: Monad, radial, isopolar, triangular-obtuse-convex; triporate, endopores costate, costae 2-3 µm wide, 2 µm thick, pores lolongate, pores 1 µm wide, 2 µm long; semitectate, exine 3 µm thick, nexine 1 µm thick, columellae 1.0 µm wide, 2 µm apart, well distinct, tectum 1.0 µm thick; sculpture reticulate, lumina 2-5 µm wide, elongated, sinuous, simplicolumellate, muri 1 µm wide, curvimurate. Dimensions: equatorial length 29 µm; equatorial width 29 µm; equatorial diameter length/width 1, n=1. Comparisons Spirosyncolpites spiralis Gonzalez, 1967 is tricolpate and exine thicker (9 µm). Retitriporites amplireticulatus (Jaramillo & Dilcher, 2001) has lumina wider (6-8 µm) and pores indistinct. Retitriporites mirabilis (Regali et al. 1974) is larger (80 µm). Retitriporites dubiosus Gonzalez, 1967 has lumina smaller (0.8 µm). Retitriporites federicii Gonzalez, 1967 has annuli is larger (5 µm). Retitriporites simplex Van der Kaars, 1983 has lumina smaller (< 1 µm).

Genus Rhoipites Wodehouse, 1933

Rhoipites gigantiporus n. sp. Plate 7, Figs. 3, 4, 5, 6

Diagnosis: Tricolporate, prolate, mid-sized (33-35 µm), reticulate, semitectate, pores large, costate. Specimens: Holotype 27-87, EF: L48 4 pl. 7, figs. 3, 4, paratype: 27-60, EF: W25 2, 27-28, EF: G35 2/4 pl. 7, figs. 5, 6 Type locality: Well 1AS-27-AM Etymology: After the pores size. Description: Monad, radial, isopolar, prolate; tricolporate, colpi short, colpi 25 µm long, CPi 0.71, simple, borders straight, ends pointed, pores costate, costae 1 µm wide, 0.5 µm thick, pores 7 µm wide, pores 6 µm long, lalongate; semitectate, exine 2 µm thick, nexine 0.3 µm thick, columellae 1.4 µm high, 0.5 µm wide, 1 µm apart, tectum 0.3 µm thick; sculpture reticulate, homobrochate, lumina 1-2 µm wide, elongated to polygonal, muri 0.5 µm wide, simplicolumellate. Dimensions: polar diameter 32 (34.3) 35 µm, SD 1.2, equatorial diameter 16 (21.1) 25 µm, SD 2.8, polar/equatorial 1.6, n=8. Comparisons: Retitricolporites wijmstrae Hoorn, 1994 colpicostate. Rhoipites guianensis Van der Hammen&Wymstra, 1964 JARAMILLO&DILCHER, 2001 has lumina decreasing towards colpi. Retitricolpites wijningae (Hoorn, 1994) is tricolpate. Genus Rubipollis Mildenhal & Pocknall 1989

Rubipollis muellerae n. sp. Plate 5, Figs. 31, 32

Diagnosis: Tricolporate, circular, mid-sized (21-28µm), reticulate, heterobrochate, semitectate, endopores costate and colpi marginate. Specimens: Holotype 27-112, EF: W26 ¾ pl. 5, figs 31, 32, paratype: 27-102, EF: R17 2 Type locality: Well 1AS-27-AM Etymology: In honor to the palynologist Jan Muller Description: Monad, radial, isopolar, circular; tricolporate, colpi mid-sized, marginate, margo 2 µm wide, margo produced by a thinning of the columellae and decreasing of the lumina of the reticulum, colpi 20 µm long, CEi 0.71, borders straight, ends pointed, apocolpia 4 µm wide, endopores costate, costae 2 µm, pores 7 µm wide, pores 4 µm high, lalongate; semitectate, exine 2 µm thick, nexine 0.5 µm thick, columellae 1 µm high, distinct, 1 µm wide, 0.5 µm apart, tectum 0.5 µm thick, sexine decreases towards pores where becomes almost absent; sculpture reticulate, heterobrochate, lumina polygonal, 2 µm wide decreasing to 0.5 µm wide near to colpi, muri 0.5 µm wide, simplicolumellate. Dimensions: Equatorial length 21 (23.5) 28 µm, SD 3.8; equatorial width 15 (17.7) 22 µm, SD 3.8; equatorial diameter length/width 1.4, n=3. Comparisons: Rubipollis (Midenhall & Pocknall, 1989) accommodates tricolporate grains with Rubiaceae’s pollen morphology. Margocolporites vanwijhei GERMERAAD, ET AL., 1968 has colpicostate.

Genus Scabratricolpites (Van der Hammen) Gonzalez 1967

Scabratricolpites elongatus n. sp. Plate 7, Figs. 46, 47

Diagnosis: Tricolpate, per-prolate, mid-sized (38 µm), scabrate, intectate, thick exine. Specimens: Holotype 27-15, EF: V41 4 pl. 7, figs. 46, 47, paratype 27-20, EF: V31 1/2 Type locality: Well 1AS-27-AM Etymology: After the pollen shape. Description: Monad, radial, per-prolate; tricolpate, colpi long almost reaching the equator, colpi 33 µm long, CPi 0.8, simple, borders straight, ends pointed; intectate, exine 2 µm thick; sculpture scabrate, verrucae 0.5 µm high, 0.5 µm wide, 0.5 µm apart, rounded to slightly elongated, regularly distributed over entire grain. Dimensions: polar diameter 38 µm, equatorial width 9 (11) 13 µm, SD 2.8, polar/equatorial 3.6, n=2. Comparisons: Scabratricolpites thomasi Sarmiento, 1992 and Scabratricolpites tibialis Gonzalez, 1967 are tectate. Scabratricolpites angelicus Sarmiento, 1992 has exine thinner (0.5 µm thick).

Genus Siltaria Traverse, 1955

Siltaria amygdalas n. sp. Plate 7, Fig. 7

Diagnosis: Tricolporate, prolate, mid-sized (20-24 µm), micropitted, tectate, pores circular, costate, colpi marginate. Specimens: Holotype and paratypes: 27-98, EF: S48 pl. 7, figs. 7 Type locality: Well 1AS-27-AM Etymology: After the shape of the grains. Description: Monad, radial, isopolar, prolate, area polar pointed; tricolporate, colpi long, colpi 19 µm long, reaching the equator, marginate, margo 2 µm wide, borders straight, ends pointed, pores costate, costae 1 µm thick, pore 2 µm wide, pore 2 µm long, circular; tectate, exine 1.2 µm thick, nexine 0.2 µm thick, columellae 0.8 µm high, 0.5 µm apart, distinct, tectum 0.2 µm thick; sculpture micropitted, lumina <0.5 µm wide, circular, decreasing towards colpi, regular, muri <0.3 µm wide. Dimensions: Polar diameter 20 (22.3) 24 µm, SD 1.7, equatorial diameter 14 Oboh-Ikuenobe, et al., 16 µm, SD 0.8, polar/equatorial 1.5, n=4. Comparisons: Siltaria sp.1 (Jaramillo & Dilcher, 2001) has colpi costate and pores simple. Siltaria sp. 2 (Jaramillo & Dilcher, 2001) is spherical. Siltaria sp. 3 is fastigiate.

Siltaria hammeni n. sp. Plate 7, Figs. 8, 9, 10, 11, 12

Diagnosis: Tricolporate, prolate, mid-sized (25-28 µm), micropitted, tectate. Specimens: Holotype, UFP 40, EF: U35 ½ pl. 7, figs. 8, 9, 10 paratype 27-51, EF: Y 29 2 pl. 7, figs. 11, 12, 27-98, EF: H22 2 Type locality: Well 1AS-27-AM Etymology: In honor to Thomas Van der Hammen, a Dutch palynologist Description: Monad, radial, isopolar, prolate; tricolporate, colpi costate, costae 3 µm wide, 1 µm thick, colpi long, colpi 25 µm long, CPi 0.89, borders straight, ends pointed, pores simple, pores 4 µm wide, pores 2 µm long, lalongate; tectate, exine 1 µm thick, nexine 0.3 µm thick, columellae 0.4 µm high, indistinct, tectum 0.3 µm thick; sculpture micropitted, lumina <0.5 µm, wide, circular, homobrochate, muri 0.3 µm wide. Dimensions: Polar diameter 25 (28) 31 µm, SD 2.2, equatorial diameter 13 (15.3) 16 µm, SD 1.1, Polar/equatorial 1.8, n=7.

Siltaria mariposa Leidelmeyer, 1966 Jaramillo & Dilcher, 2001 Plate 7, Figs. 13, 14,15, 16, 17

Diagnosis: Tricolporate, circular, mid-sized (22-26µm), micropitted, tectate, colpi costate. Specimens: 27-27, EF: F38 3 pl. 7, Figs. 13, 14,15, 16, 17; 27-53, EF: V32 4 Description: Monad, radial, isopolar, circular; tricolporate, ectocolpi marginate, thin margo, 2 µm wide, produced by a thinning of the columellae, borders straight, ends pointed, ectocolpi short, 20 µm long, CEi 0.45, pores costate, pores 2 µm wide, 1 µm thick, lalongate; tectate, exine 1 µm thick, thickness slightly decreases towards colpi, nexine 0.2 µm thick, columellae 0.6 µm high, distinct, tectum 0.2 µm thick; sculpture micropitted, lumina <0.3 µm wide, circular, lumina decreases towards margo of the colpi, muri <0.3 µm wide. Dimensions: Polar diameter 22 µm, equatorial diameter 22 µm, polar/equatorial 1 µm, n=1; equatorial length 20 (23.7) 26 µm, SD 2.3, equatorial width 21 (23.5) 26 µm, SD 1.8, equatorial diameter length/width 1, n=6. Comparisons: Margocolporites vanwijhei Germeraad, et al., 1968 is reticulate. Margocolporites sp. 1 Jaramillo&Dilcher, 2001 2001 has two rings in the pores. Margocolporites sp. 2 Jaramillo&Dilcher, 2001 is bigger (43-50 µm). Margocolporites fastigiatus n. sp. is fatigiate.

Siltaria pseudosyncolpata n. sp. Plate 7, Figs. 18, 19

Diagnosis: Tricolporate, circular, mid-sized (29 µm), colpi marginate, pores costate, micropitted, tectate. Specimens: Holotype 19-03, EF: W 36 1, pl. 7, figs. 18, 19; paratype 27-51, EF: Q 32 4 Type localities: Well 1AS-19-AM and Well 1AS-27-AM Etymology: Description: Monad, radial, isopolar, circular; tricolporate, colpi long, colpi marginate, margo produced by a thinning of the exine, margo 3 µm wide, borders straight, ends pointed, colpi 15 µm long, CEi 0.5, pores slightly protruding, costate, costae well developed, 1 µm wide, 3 µm thick, pores 3 µm wide, pores 3 µm long, circular; tectate, exine 2 µm thick, nexine 0.5 µm thick, columellae 1 µm high, decreasing to 0.5 µm near to colpi, tectum 0.5 µm thick; sculpture micropitted, densely distributed over entire grain, lumina 0.5 µm wide, circular, muri 0.5 µm wide. Dimensions: Polar diameter 29 µm; Equatorial diameter 29 µm; polar/equatorial 1, n=1; equatorial length 30 (31) 32 µm, SD 1.4; equatorial width 29 (29.5) 30 µm, SD 0.7; equatorial diameter length/width 1.1, n=2. Comparisons: Siltaria mariposa Leidelmeyer, 1966 Jaramillo and Dilcher, 2001 has colpi almost reaching the equator and pore with costae not very well developed.

Siltaria santaisabelensis Hoorn, 1994 n. comb. Plate 7, Figs. 20, 21, 22

Diagnosis: Tricolporate, prolate, mid-sized (19 µm), micropitted, tectate, colpi and pores costate. Specimens: 27-68, EF: H51 3 pl. 7, figs. 20, 21, 22 Description: Monad, radial, isopolar, prolate; tricolporate, colpi mid-sized, colpi 14 µm long, CPi 0.77, costate, costae 1 µm wide, 1 µm thick, costae decreases from mesocolpia to apocolpia, borders straight, ends pointed, pores 3 µm wide, pores 3 µm long, circular, pores costate, costae 1.5 µm thick; tectate, exine 1 µm thick, nexine 0.2 µm thick, sculptural columellae 0.6 µm high, distinct, tectum 0.2 thick; sculpture micropitted, lumina 0.5 µm wide, circular, homobrochate, densely distributed over entire grain, muri 0.5 µm wide. Dimensions: polar diameter 19 µm, equatorial diameter 19 µm, polar/equatorial 1, n=1.

Siltaria tectata n. sp. Plate 7, Figs. 31, 32

Diagnosis: Tricolporate, prolate, mid-sized (25-31 µm), micropitted, tectate, pores simple, tectum very thick. Specimens: Holotype: 27-60, EF: T34 2 pl. 7, figs. 31, 32, paratype: 27-51, EF: P32 ½ Type locality: Well 1AS-27-AM Etymology: After the thickness of the tectum Biochronological range: from UA 1 to UA 3 Description: Monad, radial, prolate; tricolporate, colpi costate, costae 1 µm wide, 2 µm thick, colpi long, colpi 20 µm long, CPi 0.64, borders straight, constricted, ends pointed, pores simple, pore 2 µm wide, pores 3 µm long, lalongate; tectate, exine 2 µm thick, nexine 0.5 µm thick, columellae 0.5 µm high, indistinct, tectum very thick, 1 µm thick; sculpture micropitted, lumina 0.5 µm, circular, densely distributed over entire grain. Dimensions: Polar diameter 25 (27.5) 31 µm, SD 3; Equatorial diameter 19 (21.9) 25 µm, SD 2.2; polar/equatorial 1.3, n=8; equatorial length 22 (23.5) 25 µm, SD 2.1, equatorial width 15 (20) 25 µm, SD 7.1, equatorial diameter length/width 1.3, n=2. Comparisons: Foveotricolporites crassiexinus Van Hoeken-Klinkenberg, 1966 has pores costate. Retitricolporites caputoi Hoorn, 1993 has columellae longer and distinct. Psilatricolporites crassoexinatus Hoorn, 1993 is psilate.

Siltaria sp. 1 Plate 7, Figs. 23, 24, 25

Diagnosis: Tricolporate, oblate, mid-sized (22 µm), psilate, tectate, columellae organized in a reticulate pattern. Specimens: Holotype: 27-65, EF: X34 4 pl. 7, figs. 23, 24, 25, paratype: 27- 112, EF: R61 2 Type locality: Well 1AS-27-AM Biochronological range: from UA 2 to UA 7 Description: Monad, radial, isopolar, circular; tricolporate, colpi costate, costae 1 µm thick, decreasing to 0.5 µm from mesocolpia to apocolpia, borders straight, ends pointed, colpi 15 µm long, CPi 0.68, pores 4 µm wide, pores 2 µm long, lalongate with lateral ends pointed-lens shaped; tectate, exine 1.5 µm thick, nexine 0.5 µm thick, columellae 0.5 µm high, 0.5 µm wide, 1 µm apart, in plain view columellae shows highly distinct reticulate infratectum pattern, tectum 0.5 µm thick; sculpture psilate. Dimensions: polar diameter 12 (17) 22 µm, equatorial diameter 13 (17.5) 22 µm, polar/equatorial 1, n=2. Comparisons: Psilatricolporites costatus Dueñas, 1980 has tectum thicker, costae wider and thicker. Psilatricolporites normalis Gonzalez, 1967 is larger (30 µm). Psilatricolporites cyamus (van der Hammen & Wymstra, 1964) has colpi with a bridge. Psilatricolporites atalayensis Hoorn, 1993 is larger (24-31 µm), prolate, pores slightly lalongate.

Genus Striasyncolporites Germeraad, et al., 1968

Striasyncolporites anastomosatus n. sp. Plate 7, Figs. 26, 27, 28, 29, 30

Diagnosis: Syncolporate, prolate, triangular-obtuse-convex, mid-sized (41µm), striate, striation anastomosing, tectate. Specimens: Holotype 27-65, EF: M33 2/1 pl. 7, figs. 26, 27, paratype: 27-65, EF: T 63 2 pl. 7, figs. 28, 29, 30 Type locality: Well 1AS-27-AM Etymology: After the striae pattern of the grain. Biochronological range: from UA 4 to UA 7 Description: Monad, radial, isopolar, prolate, triangular-obtuse-convex; syncolporate, ectocolpi marginate, margo produced by the thinning of the sexine near to colpi, 2 µm wide, colpi 25 µm long, CPi 0.29, borders straight, apocolpia field is absent, endopores costate, costae 2 µm wide, 1 µm thick, pores 4 µm wide, pore 4 µm high, circular; tectate, exine 2.5 µm thick, nexine 1 µm thick, columellae 0.5 µm thick, indistinct, but in plain view is highly visible, showing a micropitted pattern underneath the tectum, tectum 1 µm thick, exine decreases towards colpi; sculpture striate, muri 0.5 µm wide, 0.5 µm thick, 0.5 µm apart, striae well developed, striation pattern anastomosing, longitudinally oriented, parallel to colpi. Dimensions: polar diameter 41 µm, equatorial diameter 22 µm, polar/equatorial 1.9, n=1; equatorial length 31 (37.3) 44 µm, SD 6.5, equatorial width 29 (35) 44 µm, SD 7.9, equatorial diameter length/width 1.1, n=3. Comparisons: Striatricolporites digitatus JARAMILLO&DILCHER, 2001 has “finger print” striae distribution. Striatricolporites archangelskyi HERNGREEN, 1975 has pores wider (7-10µm). Striatricolporites tenuissimus DUEÑAS, 1980 is semitectate. Striasyncolpites zwaardi (Germeraad et al., 1968) has pores highly protruding.

Genus Striatricolporites Van der Hammen, 1956 ex Leidelmeyer, 1966

Striatricolporites poloreticulatus n. sp. Plate 7, Figs. 35, 36, 37, 38, 39, 40

Diagnosis: Tricolporate, prolate, mid-sized (23-28µm), striate-reticulate, striae very tenuous, semitectate, heterobrochate. Specimens: Holotype 27-65, EF: S 28 3 pl. 7, Figs. 35, 36, 37, paratype: 27- 68, EF: J54 2 pl. 7, Figs. 38, 39, 40 Type locality: Well 1AS-27-AM Biochronological range: from UA 1 to UA 5 Etymology: After the reticulate pattern between striae. Description: Monad, radial, prolate; tricolporate, colpi costate, costae 1 µm wide, 1 µm thick at the equator, decreasing to 0.5 µm thick from mesocolpia to apocolpia, colpi 18 µm long, CPi 0.78, borders straight, ends pointed, pores simple, pores 4 µm wide, pores 2 µm high, lalongate; semitectate, exine 1 µm thick, nexine 0.2 µm thick, columellae 0.6 µm thick, distinct, 0.5 µm wide, 1 µm apart, tectum 0.2 µm thick; sculpture striate-reticulate, striae is long, parallels to the colpi, very thin, 0.5 µm wide, muri 0.5 µm wide, very tenuous, also reticulate, heterobrochate, lumina decreasing from apocolpia to mesocolpia where becomes micropitted, in apocolpia area lumina 0.5 µm wide, polygonal. Dimensions: polar diameter 23 (26) 28 µm, SD 2.2, equatorial diameter 16 (18.9) 21 µm, SD 2.2, polar/equatorial 1.4, n=4; Equatorial length 22 µm, equatorial width 21µm, equatorial diameter length/width 1, n=1. Comparisons: Striacolporites Sah&Kar, 1970 accommodates tricolporate, striate-reticulate grains that have lolongate pores. Striatricolporites Van der Hammen, 1956 ex Leidelmeyer, 1966 although it was doubtfully validate Jansonius&Hills, 1976 card 2726 is herein accepted. Striatricolporites Leidelmeyer, 1966 accommodates tricolporate and striate grains. Striatricolporites digitatus JARAMILLO&DILCHER, 2001 is coarsely striate and tectate. Striatricolporites tenuissimus Dueñas, 1980 is not reticulate.

Genus Syncolporites Van der Hammen, 1954

Syncolporites sp. 1 Plate 7, Figs. 33, 34

Diagnosis: Syncolporate, triangular-acute-slightly convex, mid-sized (23-24 µm), psilate, tectate. Specimens: 27-58, EF: K40 4 pl. 7, figs. 33, 34 Description: Monad, radial, isopolar, triangular-acute-slightly convex; syncolporate, syncolpi simple, borders straight, apocolpia field is present, 4 µm wide, pores vestibulate, costate, costae 1.5 µm wide, 1 µm thick, pores 1 µm wide, 1 µm high, circular; tectate, exine 1 µm thick, nexine 0.2 µm thick, columellae 0.6 µm high, tectum 0.2 µm thick; sculpture psilate. Dimensions: equatorial length 23 (23.7) 24 µm, SD 0.6, equatorial width 22 (24) 25 µm, SD 1.7, polar/equatorial 1, n=3. Comparisons: Syncolporites anibalii Hoorn, 1994 apparently is heterobrochate. Psilasyncolporites sp. 2 (Jaramillo & Dilcher, 2001) has apocolpia field is absent.

Genus Tetracolporopollenites Pflug&Thomson, 1953 in Thomson&Pflug, 1953

Tetracolporopollenites sp. 1 Plate 7, Figs. 41, 42

Diagnosis: Tricolporate, mid-sized (20 µm), psilate, atectate. Specimens: 27-68, EF: U48 ¾ pl. 7, figs. 41, 42 Biochronological range: from UA 1 to UA 7. Description: Monad, radial, prolate; tricolporate, colpi 8 µm long, CEi 0.4, simple, indistinct, borders straight, ends pointed, pores costate, costae 3 µm wide, 2 µm thick, costae gradually decreasing from mesocolpia to apocolpia, pores fused together showing a sulcus, lalongate, 8 µm wide, 2 µm high; atectate, exine 1 µm thick in the polar area, 2 µm thick in the apocolpia; sculpture psilate. Dimensions: polar diameter 20 (21.5) 23 µm, SD 2.1, equatorial diameter 14 (15.5) 17 µm, equatorial diameter length/width 1.4, n=2. Comparisons: Tetracolporopollenites maculosus (Regali et al., 1974) Jaramillo & Dilcher, 2001 is larger (24-36 µm) and pores are less lalongate.

Genus Tricolpites Cookson ex Couper, 1953

Tricolpites? pseudoclarensis n. sp. Plate 7, Figs. 48, 49

Diagnosis: Tricolpate, circular, mid-sized (40 µm), semitectate, reticulate, colpi slightly marginate, heterobrochate. Specimens: Holotype 27-68, EF: U47 3/4 pl. 7, Figs. 48, 49, paratype 27-51, EF: H44 1/3 Type locality: Well 1AS-27-AM Etymology: After the similarity of T. clarensis Description: Monad, radial, circular; tricolpate, colpi long, slightly marginate, 2 µm wide, produced by decreasing of the lumina, colpi 30 µm long, CEi 0.8, polar area 8 µm wide, borders straight, ends pointed; semitectate, exine 1.5 µm thick, nexine 0.8 µm thick, columellae 0.8 µm high, distinct, 0.5 µm wide, 0.5 µm apart, tectum 0.3 µm thick; sculpture reticulate, lumina 1-2 µm wide, heterobrochate, decreasing towards both colpi and apocolpia, polygonal, muri 0.5 µm wide, curvimurate, simplicolumellate. Dimensions: equatorial length 32 (36) 40 µm, SD 5.7, equatorial width 30 (33.5) 37 µm, SD 4.9, equatorial diameter length/width 1.1, n=2. Comparisons: Tricolpites Cookson ex Couper, 1953 accommodates tricolpate grains, with reticulum regular over grain. Tricolpites clarensis Gonzalez, 1967 Jaramillo&Dilcher, 2001 has lumina smaller (0.7-1 µm) and is tectate. Tricolpites antonii Gonzalez, 1967 Jaramillo and Dilcher, 2001 is smaller (26 µm).

Genus Zonocostites Germeraad, et al., 1968

Zonocostites equatorialis n. sp. Plate 7, Figs. 43, 44, 45

Diagnosis: Tricolporate, prolate, mid-sized (23-28 µm), micropitted at the apocolpia, psilate at the mesocolpia, intectate, zonosulculate. Specimens: Holotype 27-60, EF: S35 2/4 pl. 7, Figs. 43, 44, 45. Type locality: Well 1AS-27-AM Etymology: After the presence of zonosulculus Description: Monad, radial, isopolar, prolate; tricolporate, colpi long, simple, intruding, borders straight, ends pointed reaching polar area, colpi 15 µm long, CPi 0.6, the pores are fused together forming a zonasulculus, borders simple, pores 4 µm high; intectate, exine 1 µm thick, exine thicker in polar area; sculpture micropitted at the apocolpia, lumina <0.5 µm, circular, densely distributed, psilate at the mesocolpia. Dimensions: Polar diameter 23 (25.5) 28 µm, SD 3.5; Equatorial diameter 18 (19.5) 21 µm, SD 2.1; polar/equatorial 1.3, n=2. Comparisons: Zonocostites minor (Jaramillo and Dilcher, 2001) is smaller (16 µm).

5. Acknowledgements

We thank to the Smithsonian Tropical Research Institute and INPA where this research was carried out. We also thank DNPM, especially Dr. Fernando Burgos and Gert Woeltje for the sampling permits of the Amazon cores. We thank to ICP-Instituto Colombiano de Petroleo to samples procedure. Thanks to Dr. Jackson Paz, MsC. Carlos Arias, Dr. Fatima Leite, Dr. Edgardo Latrubesse for the cooperation in some graphs herein used and comments. This study was supported by CAPES and CNPq. To Carmen Schloeder by the abstract translation.

6. References

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7.0 explanations of plates

Plate 1 1,2,3 Cingulatisporites peruanus (Hoorn, 1994a) n. comb. 4,5,6 Cingulatisporites rugulatus n. sp. 7 Crassoretitriletes vanraadshoovenii Germeraad et al. 1968. 8,9 Cyathidites sp. 1 10 Deltoidospora adriennis (Potonié & Gelletich, 1933) Frederiksen, 1983 11,12,13,14 Distaverrusporites margaritatus (Muller, 1968) 15,16 Echinatisporis circularis n. sp. 17,18 Foveotriletes ornatus (Regali et al., 1974) 19,20 Kuylisporites waterbolkii Potoníe, 1956 21 Echinatisporis muelleri Regali et al. 1974 n. comb. 22 Magnastriatites grandiosus (Kedves & De Porta, 1963) (Dueñas, 1980b) 23,24 Hydrosporis minor n. sp. 25,26 Polypodiaceiosporites? laevigatus n. sp. 27,28 Microfoveolatisporis sp. 1 29,30 Matonisporites muelleri Playford 1982

Plate 2 1,2,3 Polypodiaceiosporites pseudopsilatus Lorente 1986 4,5 Polypodiisporites pseudoreticulatum n. sp. 6,7 Polypodiisporites aff. specious Sah, 1967 8,9 Polypodiisporites usmensis (Van der Hammen, 1956b) (Germeraad et al., 1968) Khan & Martin, 1972 10,11 Polypodiisporites? planus n .sp. 12,13 Psilatriletes lobatus (Hoorn, 1994a) 14,15 Psilatriletes sp.1 16,17,18 Pteridaceoisporis gemmatus n. sp. 19,20 Tuberositriletes? crassitudatis n. sp. 21,22 Rugulatisporites sp. 1 23,24 Verrucatotriletes bullatus (Van Hoeken-Klinkenberg, 1964) 25,26 Retitriletes murielevatus n. sp.

Plate 3 1,2 Arecipites perfectus n. sp. 3,4 Arecipites? polaris n. sp. 5,6 Bombacacidites araracuarensis (Hoorn, 1994b) 7,8,9 Bombacacidites simpliciriloensis n. sp. 10,11,12 Bombacacidites sp.1 13 Bombacacidites zuatensis Lorente, 1986 14,15,16 Bombacacidites fossulatus n. sp. 17,18 Bombacacidites nacimientoensis Anderson, 1960 Elsik, 1968 19,20 Cistacearumpollenites poruscircularis n. sp. 21,22 Byttneripollis ruedae n. sp. 23,24 Corsinipollenites oculusnoctis Thiergart, 1940 Nakoman, 1965 25 Corsinipollenites oculusnoctis Thiergart, 1940 Nakoman, 1965 (Tetrads) 26,27,28 Cichoreacidites longispinosus Lorente, 1986 n. comb. 29 Clavainaperturites microclavatus (Hoorn, 1994a) 30,31 Corsinipollenites scabratus n. sp. 32,33 Corsinipollenites collaris n. sp.

Plate 4 1,2 Cricotriporites sp.1 3,4 Crotonoidaepollenites reticulatus n. sp. 5,6,7 Crototricolpites finitus (Equatorial view) n. sp. 8,9 Crototricolpites finitus (Polar view) n. sp. 10,11,12 Ctenolophonidites suigeneris n. sp. 13,14 Dicolpopollenites obtusipolus (Paratype) n. sp. 15,16 Dicolpopollenites obtusipolus (Holotype) n. sp. 17,18,19 Echiperiporites estelae Germeraad et al. 1968 20,21 Echiperiporites jutaiensis n. sp. 22,23 Echiperiporites lophatus n. sp. 24,25 Gomphrenipollis minima n. sp. 26,27 Echiperiporites intectatus n. sp. 28,29,30 Heterocolpites brevicolpatus n. sp. 31 Foveotricolporites pseudodubiosus n. sp. 32,33,34 Glencopollis curvimuratus n. sp. 35,36 Heterocolpites rotundus Hoorn, 1993 37,38 Heterocolpites verrucosus Hoorn, 1993 39,40 Foveotricolporites lenticuloides (Holotype) n. sp. 41,42 Foveotricolporites lenticuloides (Paratype) n. sp. 43,44 Horniella caribbiensis (Muller et al., 1987) n. comb.

Plate 5

1,2 Horniella morenoi n. sp. 3,4 Ladakhipollenites floratus n. sp. 5,6 Inaperturopollenites sp.1 7,8 Ladakhipollenites rectangularis (Holotype) n. sp. 9,10 Ladakhipollenites rectangularis (Paratype) n. sp. 11,12 Horniella? megaporatus n. sp. 13,14,15 Ilexpollenites tropicalis n. sp. 16,17 Loranthacites psilatus n. sp. 18,19 Loranthacidites sp. 1 20,21 Lakiapollis costatus n. sp. 22,23,24 Malvacipolloides sp.1 25,26 Malvacipolloides maristellae (Muller et al., 1987) n. comb. 27,28 Malvacipolloides sp. 2 29,30 Meliapollis? sp. 1 31,32 Margocolporites muellerae n. sp. 33,34 Margocolporites fastigiatus (Holotype) n. sp. 35,36 Margocolporites fastigiatus (Paratype) n. sp. 37,38 Monocolpopollenites sp 1 39,40 Margocolporites pseudodemicolpatus n. sp. 41,42 Margotricolporites sp.1 43,44 Malvacipolloides? sp. 3

Plate 6 1,2 Multiporopollenites crassinexinatus n. sp. 3,4 Paleosantalaceapidites sp. 1 5,6 Parsonisidites? brenacii n. sp. 7,8,9,10 Psilabrevitricolporites devriesi Lorente 1986 n. comb. 11,12,13 Psilabrevicolpites flexibilis van Hoeken-Klinkenberg, 1966 14,15 Psilabrevitricolporites sp. 1 16 Proxapertites tertiaria Van der Hammen & Garcia 1966 17,18 Psilastephanoporites herngreenii Hoorn 1993 19,20 Retibrevitricolpites sp. 1 21,22,23 Retistephanocolporites sp.1 24,25 Psilaperiporites sp. 1 26,27,28 Psilastephanoporites sp. 1 29,30 Retitrescolpites sp. 2 31,32,33 Retistephanocolpites circularis n. sp. 34,35,36,37 Retibrevitricolporites yavarensis Hoorn 1993 n. comb. 38,39 Retitrescolpites? sp. 1 40,41 Retitrescolpites? costelas (Paratype) n. sp. 42,43,44 Retitrescolpites? costelas (Holotype) n. sp. 45,46 Retitriporites rotundus (Paratype) n. sp. 47,48 Retitriporites rotundus (Holotype) n. sp.

Plate 7 1,2 Retitriporites sp. 1 3,4 Rhoipites gigantiporus n. sp. 5,6 Rhoipites gigantiporus n. sp. 7 Siltaria amygdalas n. sp. 8,9,10 Siltaria hammeni n. sp. 11,12 Siltaria hammeni n. sp. 13,14,15,16,17 Siltaria mariposa Leidelmeyer, 1966 Jaramillo and Dilcher, 2001 18,19 Siltaria pseudosyncolpata n. sp. 20,21,22 Siltaria santaisabelensis (Hoorn, 1994b) n. comb. 23,24,25 Siltaria sp.1 26,27 Striasyncolporites anastomosatus (Holotype) n. sp. 28,29,30 Striasyncolporites anastomosatus (Paratype) n. sp. 31,32 Siltaria tectata n. sp. 33,34 Syncolporites sp. 1 35,36,37 Striatricolporites poloreticulatus (Holotype) n. sp. 38,39,40 Striatricolporites poloreticulatus (Paratype) n. sp. 41,42 Tetracolporopollenites sp. 1 43,44,45 Zonocostites equatorialis n. sp. 46,47 Scabratricolpites elongatus n. sp. 48,49 Tricolpites? pseudoclarensis n. sp.

4 5

1 2 3

8 9 7 10

13 14

11 12 15 16

21 17 18 19 20

23 24 25 26

27 22 28 30 1 23 4 5

67 8 9

14 12 13 15

19 20

16 17 18

21 22

23 24 25 26 3 4 1 2 5 6

7 8914

10 11 12

13 15 16

19 20 21 22

17 18

26 27 28

23 24 29 25

30 31 32 33 1 5 6 7

23 4 8 9

10 11 12 13 14

15 16

20 21 17 18 19

24 25 26 27

22 23 28 29 30 31

35 36

32 33 34 37 38

39 40 41 42 43 44 3 4 1 2 5 6

11 12 7 8910 13 14 15

20 21 16 17 18 19

22 23 24 25 26

27 28 29 31 32 33

30 35 36 34 37 38

39 40 41 42 43 44 5 6 1 2 3 4

7 8 9 10

11 12 13 16 14 15

19 20 24 17 18

21 22 23

26 27 28 29 30

34 35 36 37 31 32 33

38 40 41 45 46

39 47 48 42 43 44 1 2 3 4 5 6 7

18 8 9 10 13 14 19

20 21 22 15 16 17 11 12

26 27 23 24 25

31 32 33 34 28 29 30

41 42 43 44 45 35 36 37

38 39 40 46 47 48 49 ANEXO II: PAPER PUBLICADO DISCUTINDO OS PROBLEMAS BIOESTRATIGRÁFICOS DO MIOCENO DA AMAZÔNIA

Journal of South American Earth Sciences 23 (2007) 61–80 www.elsevier.com/locate/jsames

Late Miocene continental sedimentation in southwestern Amazonia and its regional signiﬁcance: Biotic and geological evidence

Edgardo M. Latrubesse a,*, Silane A.F. da Silva b, Mario Cozzuol c, Maria Lu´cia Absy b

a Universidad Nacional de La Plata, FCNyM, Instituto de Geomorfologia y Suelos-IGS, Calle 3 N 584, (1900), La Plata, Argentina b Instituto Nacional de Pesquisas da Amazoˆnia, INPA-National Institute of Amazon Research, Laborato´rio de Palinologia, Avenida Andre´ Arau´jo, No. 2936, Aleixo 69011-970, Manaus, Amazonas, Brazil c Laboratorio de Paleontologia Museu de Cieˆncias e Tecnologia, PUC-RS, Avda. Ipiranga 6681, Porto Alegre, RS, Brazil

Received 1 July 2004; accepted 1 June 2006

Abstract

Fossil content (vertebrate paleofauna and palynology) indicates that the sediments of the Solimo˜es Formation in Acre (SW Brazilian Amazonia) are continental, having been deposited by avulsive fluvial belts in a floodbasin–floodplain environment. The main source area was the Andes chain. Widespread lacustrine swampy deposits, stacked channel deposits, and paleosoils are typical elements that characterize the Solimo˜es Formation sediments that outcrop in southwestern Brazilian Amazonia. New data on fossil vertebrate assemblages and palynology corroborate the Late Miocene age suggested previously and assign the fossils to the Huayquerian mammalian biozone, spanning 9– 6.5 Ma. These geological and paleontological data show that the existence of an intracontinental seaway through SW Amazonia during the Late Miocene (11–10 Ma), connecting the Caribbean Sea with the Parana Basin as previously proposed is unsustainable, because the sediments used by previous authors to propose the seaway were deposited in a continental environment and are younger than 11–10 Ma. Ó 2006 Elsevier Ltd. All rights reserved.

Keywords: Solimo˜es formation; Amazon; Paleogeography; Paleoecology; Late Miocene

1. Introduction obtained were discussed with specialists from several coun- tries. This article presents new evidence and synthesizes our The Amazon, the world’s largest ﬂuvial system, is of results in relation to these issues. fundamental importance for understanding Late Cenozoic During recent decades, preliminary data sets pertaining environmental change. However, much of Amazonia is to the Cenozoic sediments of SW Amazoˆnia have been gen- inaccessible and has not been studied in detail, and the lim- erated (Radambrasil, 1976, 1978; Latrubesse, 1992; Latru- ited investigations to date have resulted in many controver- besse et al., 1997). One of the best known publications, by sies. Brazilian researchers (including the authors) have been Ra¨sa¨nen et al. (1995), proposed the existence of an intra- working since the 1990s on the Neogene record of south- continental seaway through western Amazonia, linking western Brazilian Amazonia. Part of Amazonia, consisting the western Caribbean with the Rio de la Plata estuary of the Brazilian state of Acre and neighboring parts of via western Amazonia and the modern Parana drainage Amazonas and Rondonia, were visited by an IGCP 449 basin (Fig. 1). ﬁeld excursion organized by E.M. Latrubesse and J.C. This proposal been received favorably by some research- Stevaux in 2003 (e.g., Westaway, 2006), when some of these ers, mainly paleontologists and biogeographers who regard controversies were discussed at length and the results it as a new paleogeographic alternative to understanding biogeographic patterns in South America (Webb, 1996; Lovejoy et al., 1998, 2006; Albert et al., 2006). However, * Corresponding author. this seaway model has received some criticism (Hoorn, E-mail address: [email protected] (E.M. Latrubesse). 1996; Marshall and Lundberg, 1996; Praxton et al.,

Fig. 1. (A) Inset showing the seaway inferred to have existed during the Late Miocene by Ra¨sa¨nen et al. (1995), connecting the Caribbean Sea with the south Atlantic through the Venezuelan/Colombian Llanos Basin, western Amazonia, the Beni-Chaco plain, and the Parana Basin in Argentina. (B) Late Miocene model proposed herein. The position of the ﬂat slab of the central Andes at 2–15°S is indicated. The Late Miocene deposits of the Mesopotamian (lowermost levels of the Ituzaingo Formation) and the Kiyu´ Formation in the La Plata Basin, the Urumaco Formation in Venezuela, and the continental sedimentation of the Solimo˜es Formation is recorded. The occurrence of Late Miocene discordance in the coastal Barreiras Formation (BFD) sediments and the intra-Chaco discordance in Bolivia (ICHD) is indicated. In the sub-Andean Chaco area of south central Bolivia, the Tariquia Formation should be recorded at this time. Hoorn (1994a) did not record Late Miocene sediments in the northernmost outcrops of the lowlands of southeastern Colombia but in the Paleozoic rocks of the Araraquara Formation and the outcrops of the lower–middle Miocene sediments Marin˜ame unit (L/MM?), which should be an obstacle for marine ingressions in the early Late Miocene coming from the Caribbean Sea (Hoorn, 1993).

1996), but only circumstantial evidence against it was pre- Branco to Sena Madureira city, in SW Amazonia, inter- sented. For this reason, geologists working in the Parana– preting them as deposited within tidal flats and estuarine Chaco Basin were tempted to correlate data from the Cha- environments. We are familiar with these and many other co Basin with sediments outcropping in Acre, speculating outcrops but interpret the same deposits differently. Late on marine connections and ingressions from both basins Cenozoic sediments, mainly sandstones, siltstones, and in the Bolivian Chaco during the Late Miocene (Hernandez claystones, cover most of western Amazonia and have been et al., 2005; Hulka et al., 2006). A new publication by interpreted independently as deposited in a continental Rebata et al. (2006) on the Pastaza–Maranõn Basin contin- fluvial/lacustrine environment (Radambrasil, 1976, 1978; ues to postulate marine incursions in southwestern Amazo- Latrubesse, 1992). These sediments were included in a sin- nia during the Late Miocene. We show that the existence of gle lithostratigraphic unit named the Solimoes Formation such an intracontinental seaway is unsustainable in the (Caputo et al., 1971), which reaches thicknesses of up to middle–later part of the Late Miocene, in light of the geo- 1800 m (borehole I Nst-1-AM; Radambrasil, 1978); in Acre logical and paleontological evidence presently available in state, these Cenozoic sediments are up to 800 m thick SW Brazilian Amazonia (the same source area of Ra¨sa¨nen (Fig. 2). Westaway (2006) has suggested that in view of et al., 1995). We also suggest that the proposal derived its vast extent and considerable thickness, this sedimentary from misunderstandings by Ra¨sa¨nen et al. (1995) of the unit could deserve at least the stratigraphic status of a stratigraphy and fossil fauna, which led those authors group, not a formation. incorrectly to correlate sediments of the Amazon and Par- Acre state is characterized by a dissected fluvial land- ana basins. scape caused by incision into the uppermost part of the Sol- imoes Formation deposits (Fig. 3). The outcrops analyzed 2. Geological interpretation by Ra¨sa¨nen et al. (1995), and investigated by us, are along river banks and roads. The relief in this region, between the Ra¨sa¨nen et al. (1995) describe outcrops on the Purus highest parts of the landscape and valley floor levels, is and Acre rivers, as well as along BR-364 road from Rio nowhere more than approximately 80 m. Therefore, we E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80 63

Fig. 2. Isopach map of the Solimo˜es Formation (from Maia et al., 1977). Numbered circular areas indicate main areas with Late Miocene fossiliferous, palynological, and/or geological data. 1, Upper Acre River; 2, Acre River upstream of Rio Branco (also studied by Ra¨sa¨nen et al., 1995); 3, BR 364 from Rio Branco to Sena Madureira; 4, BR 364 from Sena Madureira to Manuel Urbano and outcrops along the Iaco and Purus rivers; 5, Upper Jurua. Square in the northwestern corner indicates the area studied by Hoorn (1993, 1994a,b).

Fig. 3. Schematic section showing the main elements of the landscape in SW Brazilian Amazonia (lowlands). Tertiary sediments of the Solimo˜es Formation outcrop along the banks of main rivers and along the watershed areas, mainly exposed on road cuts. can discuss, at most, the uppermost 80 m of a deposit that tion structures and abandoned channels and shows reaches 800 m thick. Our surveys along the banks of the characteristic major trough cross-bedding structures and Acre, Iaco, Purus, Jurua, and Moa rivers and in road cuts ripples (Figs. 4 and 5). The predominant low-energy assem- lead us to identify two main facies assemblages: a channel- blage is composed mainly of green to grey–green clay and dominated assemblage and a ﬂoodplain–lacustrine low- silty clay and interpreted as deposited in a ﬂoodplain/ energy assemblage. lacustrine/paludal environment (Fig. 6). These sediments The channel assemblage is typically composed of red– show mainly massive structure and lamination in some brown to brown sand, silty and clayey sand, and intrafor- cases. Paleosols are marked by the presence of nodular mational mud ball beds. It is dominated by lateral accre- horizons, rhizolits, root casts, mudcracks, and mottled 64 E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80

Fig. 4. Amapa outcrops in the Acre River, upstream of Rio Branco, described by Ra¨sa¨nen et al. (1995) as a point bar generated below tidal influence generated by the seaway (location, area 2 of Fig. 2). We interpret the deposits as formed by lateral accretion structures. Note the decrease in bed thickness from 1 to 2 and floodplain-dominating deposits in the uppermost part of the profile (3) indicated in (B). The channel macroform is mainly formed by large, 20–80 cm thick sets of inclined fine-sand point bar ripple drift lamination, predominantly B type with top sets (A) and between thin beds of fine sediments (B). (C) Details of ripple drift lamination. structures (Fig. 6). In some more lacustrine sediments, con- tebrates such as bivalves and gastropods. Abundant volute structures are also found. Differences in color, vary- crocodilian coprolites have also been recorded in some ing from green or grey–green to pale red, can be attributed outcrops. to differences in water depth and oxygenation. Lignite beds The channel assemblage can be interpreted in terms of are scarce in the swampy lacustrine sediments that crop out active and unstable channels with sequences of fining- in Acre. However, in some localities, such as the upper upward sediments and cycles of cut and fill. Point-bar Acre River, it is possible to find fossilized wood and other accretion surfaces are formed by fine-grained sediment organic matter or pyrite associated with woody fragments (fine sand, silt, mud), with ripple structures predominant or organic beds. in the bedsets of these lateral accretion deposits. A good In both facies assemblages, fossil bones, gypsum example of fine, dominated point bar deposits are those veins, and calcareous concretions occur. The sediments described by Ra¨sa¨nen et al. (1995) at Seringal Amapa, in are rich in the bones of autochthonous and para- the Acre River, as a point bar that formed under the influ- utochthonous vertebrates and bones and shells of inver- ence of tidal conditions. We posit that the outcrop repre- E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80 65

Fig. 5. (A) Channel macroform related to crevasse splay or small delta in water-saturated environment, road cut, BR 364 from Rio Branco to Sena Madureira (9°26058.97 S, 68°23029.97 W, area 3 of Fig. 2). (B) Channel cuts and enters lacustrine/marshy deposits. Road cuts BR 364 from Rio Branco to Sena Madureira. (B–D) Relate to this kind of deposit in outcrops along the same area. (B) Sandy sets of the channel environment with B-type ripples; (C) convolute beds in fine lacustrine deposits; (D) intraformational conglomerate indicating flash entrance and/or reactivation of a channel in a splay/delta. Sediments indicate channel erosion in a depositional plain. Mudballs are the coarser fraction, transported very short distances, by the suspended load fluvial systems of the Solimo˜es Formation. sents a fluvial point-bar deposit with rapid fine sedimenta- are typical channel lithofacies that represent channel reaction. This channel macroform is mainly formed by 20– tivation inside an aggradational fluvial system with a ten- 80 cm thick, inclined, fine-sand point-bar ripple drift lami- dency toward subsidence, which erode/run on a muddy nation, predominantly B type with topsets (Fig. 4A and B). river bed cutting floodplain or lake deposits. Mudballs Bottomsets (total 5 cm thick) indicate high sedimenta- are eroded and shortly transported by several processes, tion rates. The 10–20 cm thick, intercalated, massive, such as erosion in a muddy bottom channel; the entrance muddy beds suggest backwater ponding, as interpreted of a channel in muddy sediments, mainly in a saturated by Westaway (2006). Thus, these kinds of deposits indicate floodplain/lake; the generation of a new fluvial belt by highly seasonal behavior, with peaks of suspended sedi- avulsion that cut the fine-grained sediments of the flood- ment transport (producing sand laminations) alternating plain again; and mass movements along the banks that with rapid falls in water level or slackwater effects (produc- introduced sediments into the channel. All these mecha- ing mud laminations). Such deposits are widespread nisms are recorded in the sediments of the Solimo˜es throughout the Solimo˜es Formation. Formation. Other important sedimentological aspects in the chan- Large channel macroforms are clearly associated with nel assemblages include the presence of nonrepetitive floodplain deposits and lateral and vertical relations scroll structures and abruptly abandoned channels, typi- between channel macroforms, and floodplain deposits can cally without oxbow-lacustrine deposits. Thus, avulsion be identified in the field (Fig. 5). These fluvial systems typ- was an important mechanism of channel adjustment. ically transported fine-grained suspended sediments. Associated with paleochannel features, abundant finely The association of sedimentary environments, such as laminated to massive fine sediment plugs can be found, widespread shallow lacustrine swampy deposits, paleosols, which indicate that channels were filled quickly by fine- and stacked channel deposits, with abundant terrestrial grained sediments. Coarse sediments are represented and and aquatic vertebrate remains indicates the existence of restricted to intraformational mudballs (Fig. 5). Mudballs a large floodbasin, exhibiting floodplain surfaces with 66 E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80

Fig. 6. (A) Pedogenic features in floodplain deposits (massive silty/clayey sediments) in road outcrops of BR 364, location 9°37017.25 S, 68°14012W, area 3 of Fig. 2. (B) Paleosoils characterized by blocky peds, mottles, root casts, and rhizoliths. Floodplain paleosoils are covered by ‘‘wetter’’ floodplain deposits with less pronounced pedogenetic features (above arrows). (C) Paleosoil in a Acre River bank outcrop upstream of profile described by Ra¨sa¨nen et al. (1995), in Amapa (area 2, Fig. 2). The outcrops extend from 10°0201.7400S, 67°52029.09W to some hundreds of meters upstream on the left banks of the Acre River. The paleosoil is found in a fine sediment-dominated sequence of floodplain deposits. Vertebrates and freshwater bivalves occur in floodplain deposits, such as Pachydon sp., Castalia sp., Prisodon sp., Diplodon sp., and Mycetopoda sp. (material identified by Marıá Ineˆs Feijo´ Ramos, Museu Paraense Emilio Goeldi, Bele´m, Brazil). (D) Floodplain deposits in Preventorio, left bank of the Acre River, Rio Branco urban area. Arrows indicate vertebrate fossiliferous levels. Remains of Late Miocene vertebrates stored in the Laborato´rio of Paleontological Research of the Federal University of Acre; the most spectacular piece is a jaw of the giant crocodile Purusaurus brassiliensis. paleosols, avulsive channel systems, crevasse splays, and Bolivia, Paraguay, and northern Argentina. The climate deltaic environments. is wet/dry tropical, with annual precipitation decreasing Several other Late Cenozoic sedimentological systems from 1000 to 2500 mm in the sub-Andean zone to are closely analogous to the Solimo˜es Formation, as dis- 1200 mm in the Oriental Chaco and 400 mm in the Occi- cussed at the field conference Amazon 2003-IGCP 449 dental Chaco. Sedimentation in the Chaco consists of large (Westaway, 2006). Large depositional megafans are char- Quaternary alluvial fans formed by hyperavulsive rivers, acteristic of tropical systems. In active orogenic belts and which represent the largest fluvial-like system of coalescing foreland settings, some of the world’s largest megafans, fans in the world. These fans are formed from north to extending over thousands of square kilometers, have devel- south by the Grande, Parapetı´, P´ılcomayo, Bermejo, and oped, such as the Kosi and Gandak megafans in the Gan- Salado rivers (Iriondo, 1993; Wilkinson et al., 2006). In getic plains of India and the Parapetı´, Pilcomayo, and the Upper Paraguay Basin, a large wetland/floodbasin Bermejo fans in the Chaco plains of South America (Latru- area, the Pantanal, formed of extensive megafans (Saõ besse et al., 2005). It is widely recognized that large sedi- Lourenço, Taquarı´, etc.) is fed by the Brazilian highlands ment loads, frequent avulsion, low longitudinal gradients, close to the megadepositional fans system to the east. These and highly variable flow regimes are major factors control- megafans are formed by well-delimited alluvial belts creat- ling the development of such fans. ed during humid periods and smaller and less stable paleo- An approximately similar modern analogue environ- channels active during dry periods as a response to the ment to the Solimo˜es Formation deposits cropping out in climatic changes of the Late Quaternary. Avulsion is the Acre is suggested by the Quaternary Chaco system. With main mechanism producing abandoned alluvial belts, with an area of >800,000 km2, the Chaco plain spreads across fine sediments predominant in the plains (Assine, 2005). E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80 67

Swampy areas are widespread, with more than 125,000 km2 of the Bermejo and Pilcomayo fans flooded (Iriondo, 1993). Parts of the Chaco and Pantanal are hyposaline. Sediments deposited by hyperavulsive systems in a foreland basin are also recorded in some units of the Lower and Middle Siwalik deposits and their modern analogues in the Gangetic plain (Jain and Sinha, 2003). These fluvial sequences are characterized by a predominance of stacked sandstones and overbank mudstones, paleosols, and abundant fossil content (e.g., Beherensmeyer, 1987; Beherens- meyer and Tauxe, 1982; Willis and Behrensmeyer, 1994; Bhatia, 2003; Kumar et al., 2003). The Chaco, Indogangetic plain, and Solimo˜es Forma- tion deposits indicate broadly similar processes of sedimentation. The most important difference is that deposition Fig. 7. Fossiliferous outcrop of the Solimo˜es Formation in the Acre River was more distal and conditions were wetter in the Amazon upstream of Brasileia, Calvalcante locality (10°5504200S, 69°4905300W, area during the Upper Miocene than in the Quaternary of the 1 of Fig. 2). The remains belong to a Late Miocene Toxodontidae found in the low-energy facies assemblage. Chaco and the Late Miocene Siwaliks, as indicated by the tropical fauna and vegetation recorded in the Solimo˜es Formation. Aeolian deposits, common in Chaco, and thick calcrete paleosoils, found in the Indogangetic plain, have South America, comprising 51 genera. The fossils were col- not been recorded in the Solimo˜es Formation. Conversely, lected along river banks and from the uppermost levels permanent water bodies (swamps, shallow lakes) were cropping out on the hills of the lowland dissected plain widespread during deposition of the Solimoes Formation, (Fig. 3). Most species can be found in the Laboratorio de indicating that southwestern Amazonia acted as a floodba- Pesquisas Paleontolo´gicas of the Federal University of sin similar to the present-day Pantanal system but fed from Acre in Rio Branco. Fossils have been mainly found the Andes. in situ in both facies assemblages, but the floodplain/lacustrine/paludal assemblage has yielded more complete assem- 3. Fossil vertebrates and their interpretation blages with better preservation because of the low-energy depositional environment (Fig. 7). Land mammal assemblages are the most used biostrati- We reviewed the fossil record of vertebrates from the graphic evidence to correlate Tertiary continental deposits Solimo˜es Formation in SW Brazilian Amazonia, the Uru- in South America (Flynn and Swisher, 1995). As a conse- maco Formation in Venezuela, and the Mesopotamian of quence of isolation during most of the Cenozoic, because Argentina (Table 1). The data from Acre were taken from of the absence of a land bridge linking South and North previous publications, mainly Campbell et al. (2000), America, South America has a distinct Cenozoic fauna. Latrubesse et al. (1997), and from the collections of the This uniqueness has long been recognized, notably as a Laborato´rio de Pesquisas Paleontolo´gicas and our own result of work on mammalian biostratigraphy by the data. Faunal data for the Mesopotamian are from Cione Argentinean paleontologist Florentino Ameghino in the et al. (2001), the collections of La Plata Museum of Natu- late nineteenth and early twentieth centuries. ral Sciences (La Plata city), and the Argentinean Museum Originally, Latrubesse (1992) and Latrubesse et al. of Natural Sciences ‘‘Bernardino Rivadavia’’ (Buenos (1997) proposed that the fossil fauna of Acre state belongs Aires) in Argentina, as well as our own data. Data from to the Huayquerian mammal age, possibly extending to the the Venezuelan localities are from Marshall et al. (1993), Montehermosan age. They also proposed a correlation of Sańchez-Villagra et al. (2003), and Linares (2004). the Solimo˜es Formation fossil assemblage with the Meso- Twenty genera found in Acre are also present in the potamiense from Argentina and the Urumaco in Venezue- Mesopotamian fauna of Argentina, with 11 species in com- la. Given the current evidence and the stratigraphic mon between both assemblages, including the rodents Pot- advances reached in Argentina and Venezuela, the fossil amarchus murinus, Neoepiblema horridula, Phoberomys vertebrates of Acre are now attributable to the Huay- burmeisteri, and Kiyutherium orientalis, as well as other querian–Mesopotamian South America Land Mammal amniote groups. A list of the fossil amniotes from the Mes- Age (SALMA) (9–6.5 Ma), defined mainly for Mesopota- opotamia (Argentina), Solimo˜es Formation (Brazil), and mian fauna (Cione et al., 2001). Urumaco (Venezuela) appears in Table 1. Several taxa Fossils were first recorded in Acre by the Chandless shared with the Mesopotamian fauna are also found in expedition in 1866. Fundamental reviews of these verte- Urumaco fauna from northern Venezuela, such as the tox- brates have been written by Rancy (1985, 1991) and Webb odontid Grynodon and the rodents Kiyutherium and Phob- and Rancy (1996). The vertebrate fauna of Acre is one of eromys. The Acre faunal assemblage preceded the Great the most complete and complex in the Late Miocene of American Biotic Interchange (GABI), as indicated by the 68 E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80

Table 1 Paleohoplophorus X List of the Late Miocene (Huayquerian–Mesopotamian SALMA) amniotes (mammals, reptiles, and birds) from the Solimo˜es Formation in SW Brazilian Amazonia, Urumaco Formation in Table 1 (continued) Venezuela, and the Mesopotamian (lowermost levels of Ituzaingo´ Formation) in Argentina ‘‘Mesopotamian’’ Acre Urumaco ‘‘Mesopotamian’’ Acre Urumaco Protoglyptodon X Rodentia Parahoplophorus X Brianomys X Uratherium X Carlesia X Pseudoeuryurus X Diaphoromys X Comaphorus X Doellomys X Eleuterocercus X Eumegamysops X Chlamyphractus X Isostylomys X Dasypus X Paranamys X Chasicotatus X Pentastylodon X Macroeuphractus X Pentastylomys X Proeuphractus X Pseusygmodus X Zaedius(?) X Tetrastylomys X Kraglievichia X X Protomegamys X Scirrotherium X Neoepiblema X X X Asterotemma X Phoberomys X X X Neoglyptatelus X X Kiyutherium X X X Cardiatherium X X Notoungulata Potamarchus X X X Adinotherium X Tetrastylus X X X Bernia X Gyriabrus X X Xotodon X Eumegamys X X X Eutomodus X Telicomys X X Stenotephanus X Simplimus X Haplodontotherium X ‘‘Scleromys’’ X Pachynodon X Lagostomopsys X Dilobodon X Perimys X Dinotoxodon X Protabrocoma X Eutypotherium X Eumysops X Munizia X Haplostropha X Protypotherium X X Paradoxomys X Abrothrodon X Steiromys X Gyrinodon X X Microsteiromys X Trigonodops X Cardiomys X Trigodon X Caviodon X Plesiotoxodon X Paleocavia X Toxodontherium X X Paradimys X Neotrigodon X Pliodolichotis X Neotoxodon X Anastochoerus X Mesenodon X Anchimys X Mesotoxodon X Anchimisops X Minitixodon X Contracavia X Paleotoxodon X X Plexochoerus X Oneotherium X Procardiatherium X Litopterna Protohydrochoerus X Protherotherium X X Colpostemus X Epitherium X Myocastor X Brachytherium X Xenarthra Licaphrium X X Pliomegatherium X Thoatherium X Promegatherium X Carlosoma(name?) X Pyramiodontotherium X Scalabrinitherium X Pronothrotherium X X Oxyodontotherium X Neohapalops X Mesorhinus X Pliomophus X Paranauchenia X Menilau? X Promacrauchenia X Torrellia X Culinia X Paranabradys X Sirenia Orthotherium X Ribodon X X X Amphiocnus X Cetacea Promegalonyx X Ischyrorhynchus X X X Megalonychops X Saurocetes X X X Promylodon X Prolestodon X Chiroptera Megabradys X Noctilio X Strabassodon X Sphenotherium X Proboscidea Octomylodon X Amahuacatherium X Diedomus X Octodontobradys X Primates Urumacotherium X X Acrecebus X Acretherium X Stirtonia X Pseudoprepotherium X Solimoea X Prepotherium X Carnivora Ranculus X X Cyonasua X Plohophorus X X Paraglyptodon X X Marsupialia Berthawyleria X Didelphis X Hoplophorus X Zygolestes X Trachycalyptus X Notictis X Line missing Line missing E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80 69

Stylocynus X X Achlysictys X

Table 1 (continued)

‘‘Mesopotamian’’ Acre Urumaco

Pelecaniformes Anhinga X X Macranhinga X X Gruiformes Onactornis X Andalgalornis X Charadriiformes Maegapaelus X Crocodylia Charactosuchus X X Caiman X X X Purusaurus X X Melansuchus X Mourasuchus X X X Gryposuchus X X X Hesperogavialis X X Ikanogavialis X Chelonia Fig. 8. Skull of Purusaurus brasiliensis, the largest alligatorid recorded in Stupendemys X X the Solimo˜es Formation and one of the largest predators, reaching up to Podocnemys X X 15 m in length. For comparison, see the head of an Amazon living black Chelus X X Phrynops X caiman Melanosuchus niger that reached 3.5 m in length. This cast of the Chelonoidis X Purussaurus skull is on exhibit at the Museum of Paleontology of the Lacertilia Federal University of Acre, Rio Branco, Acre, Brazil. Tupinambis X

The data from Acre were taken from the collections of the Laborato´rio de Pesquisas Paleontol- o´gicas and our own data, as well as from Campbell et al. (2000) and Latrubesse et al. (1997). Data from the Mesopotamian come from the collections of La Plata Museum of Natural Sciences (La be used as environmental indicators. The rodent Kiyutheri- um orientalis (Hydrochoeridae, Cardiatheriinae), a typical Huayquerian rodent recorded in the Solimo˜es Formation absence of immigrant mammals like Sigmodontine rodents. as well as in Venezuela, Argentina, and Uruguay, inhabited Nevertheless, some elements suggest that a low rate areas near bodies of water like the present capivaras. Prot- exchange already had been initiated at the time of connec- erotheres (Liptoterna), astrapotheres, glyptodons, pampat- tion between the Americas (Campbell et al., 2000, 2001; heres (Xenarthra, Cingulata), and ground sloths Cione et al., 2001). (Mylodontidae and Megatheriidae) indicate more terrestri- The fossil vertebrates do not support the hypothesis of a al habits in both browsing and grazing forms (Latrubesse marine environment, even though the richest faunal groups et al., 1997). The presence of Platyrrhini primates of the are aquatic: crocodilians, turtles, and fish. Giant alligator- families Cebidae and Atelidae indicate the existence of gal- ids such as Purussaurus (largest Cenozoic terrestrial preda- lery forests along the rivers. tor, 15 m long) (Fig. 8) and other alligatorids, gavials, crocod ilids, and the extinct endemic family Netosuchidae indicate a greater diversity of crocodilians in this region 4. Palynology of the Solimo˜es Formation than any other region, past or present. The river turtle family Pelomedusidae, endemic to South America, is a good The first palynological data of Cenozoic age from the indicator of stable water bodies with abundant vegetation Amazonas Basin were published by Daemon and Contre- and a tropical to subtropical climate. Bony and cartilagi- iras (1971), who suggested a Paleocene–Miocene age for nous fish, reptiles, cetaceans, and sirenians (manatees) indi- the sediments. Cruz (1984) established three palynological cate a large flooded basin with shallow lakes and swamps, zones corresponding tentatively to the Miocene, Miocene/ crossed by fluvial belts. Some fishes such as Arapaima, Pliocene, and Pliocene in cores from the CPRM/DNPM Hoplias, Colosoma, and other genera continue to be found boreholes. today in the fluvial systems of Amazon Basin. Lungfish Hoorn (1993) analyzes samples from boreholes 1AS-4a- (Lepidosirenidae) are represented by the giant extinct AM and 1AS-51-AM in Amazonas state near the border Lepidosiren megalos, similar to the smaller living L. parad- with Peru, as well as bank outcrops (Figs. 2 and 9), and oxa. Siluriformes (catfish) are the most abundant and identifies five pollen biozones for the Miocene (Fig. 10): diverse group of fish and are good indicators of freshwater the Verrutricolporites and Retitricolporites zones (Early environments. Cartilaginous fish are represented by the Miocene), the Psiladiporites–Crototricolpites zone (Early/ endemic Potamotrygonidae (freshwater stingrays), the anfi- Middle Miocene), the Crassoretitriletes zone (Middle Mio- biotic shark genera Carcharhinus, and Pristis. cene), and the Grimsdalea zone (Middle/Late Miocene). Mammals are also a highly significant aspect of the ver- We studied core samples from CPRM/DNPM borehole tebrate assemblage. Rodents are well represented and can 1AS-32-AM (Figs. 2 and 9), located approximately 70 E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80

Fig. 9. Area studied by Hoorn (1993, 1994a,b), as indicated with a square in Fig. 2. Borehole IAS 32-AM is also indicated.

Wells Outcrops

Brazil Colombia Peru Acre Bolivia Argentina- Miocene zonation Uruguay of the Solimões Formation Venezuela Urumaco-Upper “Terciario Amazonico” Pebas formation Barranco Zones da Elizete Ituzaingo Fm Age IAS-32-AM /middle members Niterói Patos (Lower levels) and Grimsdalea/ Buenos Aires Kiyu Fm-

L. F Tariquia Fm E. Spinosus IAS-4a-AM IAS-51-AM Los Chorros Bocanas Pto. Caiman

. E Grimsdalea

M./L Yecua Fm

E N Parana Fm E Iquitos Pevas D Crassoretitriletes

MIOC iddle M ? ? Sta. Isabel Psiladiporites C Mariñame Petaca Fm

Crototricolpites Early B Retitricolporites A Verrutricolporites ?

Fig. 10. Correlation of wells IAS-4a AM and IAS-51-AM with outcropping sediments in Brazilian and Colombian Amazonia, according to Hoorn (1993, 1994a,b) and data herein on Acre outcrops and well IAS 32-AM. Note random correlation of Miocene deposits along the outcrops, as proposed by Hoorn. Why small temporal diﬀerences might exist among Los Chorros, Puerto Caiman, Bocanas, and Buenos Ares inside the early Late Miocene was not explained by Hoorn, nor are they sustained by the pollen content. The correlation of the Solimo˜es Formation with the Mesopotamian of Argentina and Uruguay (lowermost levels of Ituzaingo and Kiyu formations) and the Falcon Basin in Venezuela and Tariquia Formation in Bolivia is shown.

53.5 km SW of borehole 1AS-4a-AM studied by Hoorn Samples for pollen analysis were also collected from out- (1993). We studied 13 samples in borehole 1AS-32-AM, crops of the Solimo˜es Formation sediments along the Acre between 132 and 12 m depth below ground level, at inter- River banks in the Brazil/Peru/Bolivia border area (Figs. 2 vals of around 10 m, and identify two zones (Grimsdalea and 11). Sediment samples were treated according to the and Asteraceae zones). methodology of Uesugui (1979). The preparation involved E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80 71 grinding of the samples, followed by reaction with 32% muellerii, Matonisporites sp., and Polypodiaceiosporites HCl and 40% HF, then separation using ZnCl2. A total sp., are also present in small quantities. Lorente (1986) of 300 pollen types were counted. In addition to presenting defines the base of the Grimsdalea zone by the first occur- new palynological data, we reassess some stratigraphic and rence of this species and the top as just below the first paleoenvironmental inferences proposed previously. Nota- occurrence of Echitricolpites spinosus. Retitricolpites loren- bly, our analysis of the sediments along the Acre River tae has its first occurrence in this zone, and Bombacacidites reveals no evidence of marine (or brackish-water) indica- bellus also occurs (Hoorn, 1993), which confirms the pres- tors, such as dinoflagellate cysts, foraminiferal linings, or ence of the Grimsdalea zone in this interval. mangrove assemblages, which is detrimental for the seaway In the middle part of the borehole section, 48–25 m, the model proposed by Ra¨sa¨nen et al. (1995). lithology is characterized by beds of clay intercalated with limestone. Lignite, remains of calcareous fragments, and 4.1. Samples from borehole 1AS 32-AM fossils with pyrite nodules are also found. The presence of G. magnaclavata and the absence of C. vanraadshoovenii As we already noted, the upper 132 m of borehole 1AS- suggest that this section belong to the upper Grimsdalea 32-AM were sampled, which corresponds to the Grimsdalea zone (sensu Lorente, 1986) but above the uppermost levels interval zone (sensu Lorente, 1986), with the uppermost of Hoorn (1993). Grimsdalea sp1., E. maristellae, Proxaper- part of the borehole section corresponding to the Astera- tites tertiaria, Crototricolpites annemariae, E. estelae, and ceae interval zone (sensu Lorente, 1986). Syncolporites anibalii also are present. However, a gap Three distinct intervals can be recognized. In the lower exists between 48 and 25 m, where C. vanraadshoovenii is part, 132—48 m, the lithology consists at the base of a lig- absent and E. spinosus has not appeared, possibly due to nite clay layer, followed by silt, sand, and lignite inclusions problems in the record. (1.65–0.40 cm thick). Limestone, pyrite nodules, and plant Finally, the upper part occurs between 25 and 12.1 m. debris are abundant at around 55 m depth. This interval is This interval is characterized by clay, limestone, and sand characterized by Grimsdalea magnaclavata (first occurrence beds. Its top is defined by carbonaceous clay. The first defines the base of the zone), with abundant C. vanraads- appearance of Echitricolporites spinosus, which occurs at hoovenii and P. pokornyi, plus Mauritiidites franciscoi, 25 m depth, characterizes the base of Asteraceae zone, Monoporopollenites annulatus, and D. adriennis. Other but it is not very frequently observed (<2%). This section species such as Cicatricosisporites sp., M. grandiosus, Reti- is instead dominated by G. magnaclavata, D. adriennis, tricolpites lorentae, Bombacacidites baculatus, Bombacaci- P. pokornyi, Azolla sp., Magnastriatites grandiosus, dites bellus, B. muinaerum, Corsinipollenites oculusnoctis, E. maristellae, and Proxapertites tertiaria. In addition, Verrucatosporites usmensis, Verrumonoletes sp., Verrutri- Grimsdalea sp1., V. usmensis, Clavatriletes sp., R. lorentae, letes sp., Psilamonoletes tibui, Psilatriletes sp., Echitriletes B. bellus, B. baculatus, B. muinaerum, Echitricolpites sp.,

Fig. 11. Riverbank outcrops with palynologic data from the Acre River. Outcrops located in area 1 of Fig. 2. 72 E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80

Matonisporites sp., M. annulatus, Psilatriletes sp., C. columbianus, M. vanderhamenii, and P. tibui are found in low quantities. Hoorn (1993) and Leite (2004) record the appearance of E. spinosus from the Middle Miocene (Crassoretitriletes zone), though Germeraad et al. (1968), Lorente (1986), and Muller et al. (1987) record E. spinosus from the upper Miocene, considering it a good stratigraphic marker. Other species characteristic of the Late Miocene, such as Cyathecidites annulatus, Pachydermites diederixi, and Bombacacidites ciriloensis, were not recorded in our study. Cruz (1984) records Cyathecidites annulatus, Pachy- dermites diederixi, Echitricolporites spinosus, Polypodiacei- osporites potonei, Fenestrites spinosus, Magnastriatites howardi, and Striasyncolpites zwardi in samples from the Solimo˜es Formation, considering them characteristic of the Late Miocene.

4.2. Samples from the banks of the Acre River

As we have noted, four localities on the Acre were investigated using palynological data (Fig. 11). At Patos and Nitero´i, pollen samples and vertebrates were collected from the same stratigraphic level. At Murici and Barranco da Elizete, the sediments provided pollen but no vertebrate fossils. The lithological sections of the surface localities are represented in Fig. 11 and described next. Palynological diagrams appear in Fig. 12. Murici is on the right bank of the Upper Acre River, close to the town of Assis Brasil on the Brazil–Bolivia border. The sediments from which the samples were collected are clays rich in organic material including lignite, approximately 3 m above the low-stage water level. The outcrop is characterized by an abundance of G. magnaclavata and the absence of C. vanraadshoovenii and E. spinosus. In order of abundance, the following taxa are present at Murici: G. magnaclavata, D. adriennis, Verrucatosporites usmensis, Psilatriletes sp., Monoporopollenites annulatus, Perisyncolp- ites pokornyi, Verrutriletes sp., Psilatriletes sp3., and M. grandiosus. Frequencies of up to 2% are observed for Mau- ritiidites franciscoi, Azolla sp., Bombacacidites sp3., Retitri- colporites sp2., R. porispectus, R. lorentae, Psilatricolporites minimus, Retimonocolpites sp., and P. tertiaria. Frequencies of <1% are found for Bombacacidites sp1., Retimonocolpites sp2., Chomotriletes minor, C. columbianus, E. maristellae, Echiperiporites sp1., Psilatriletes sp3., and Retitricolpites sp1. The Barranco da Elizete locality is on the left bank of the Upper Acre River. The sample, of a dark clay lens, was taken at the low-water level during the dry season (southern hemisphere winter). The presence of E. spinosus and Fenestrites sp. could indicate a Late Miocene age. The assemblage is composed of Psilatriletes sp., Verrutri- letes sp., Verrumonoletes sp., Concavisporites sp., Echitri- colporites spinosus, Psilatriletes sp2., Echitricolporites maristellae, Echiperiporites sp., Bacutriletes sp. Cicatrico- sisporites sp., Echitriletes sp., Matonisporites sp., Kuylispor- ites waterbolkii, Illexpollenites sp., Polypodiaceoisporites sp. Fig. 12. Palynological diagram of the outcrops samples of the Acre River. Retitricolpites sp., Echipollenites sp., and E. estelae. E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80 73

The sample from Patos, also on the Upper Acre River, Regarding borehole IAS-32-AM, despite its proximity was collected from the base of an intraformational con- to the core studied by Hoorn (1993), we observe paleoenvi- glomerate consisting of clay balls and silt, approximately ronmental and biostratigraphical differences. First, Zono- 0.5 m above the water level. This conglomerate is rich in costites ramonae (Rhizophora), which according to Hoorn fossil vertebrates of Huayquerian–Mesopotamian SALMA (1993) is abundant in samples from the Grimsdalea zone, age; Patos is a well-known mammal locality. The palyno- is not found in borehole IAS-342-AM. The association of logical assemblage is composed mainly of M. annulatus this species with Deltoidospora adriennis was interpreted (almost 70%), followed by E. spinosus, Echitriletes sp., Fen- by Hoorn (1993) as characterizing a costal plain environ- estrites sp., Verrumonoletes sp., Verrutriletes sp., Psilatri- ment (related to Serravallian global sea level rise, see letes sp., M. grandiosus, Azolla sp., Chomotriletes minor, Hoorn, 1993, 1994a,b; Haq et al., 1987). The absence of Cicatricosisporites sp., Psilatricolporites sp., Psilatriletes Zonocostites ramonae and the presence of D. adriennis sug- sp2., Psilatriletes sp3., Retimonocolpites sp., S. catatumbus, gest a freshwater paleoenvironment in the Grimsdalea zone and Echitriletes muellerii. At frequencies of <1%, we find (Collinson, 2002). In Hoorn’s (1993) fig. 9, the Grimsdalea Retitricolpites sp., R. lorentae, Polypodiaceiosporites sp., zone persists only up to the Middle–Late Miocene bound- Polyadopollenites sp., P. pokornyi, Podocarpidites sp., and ary, but we recorded E. spinosus in the upper section of Matonisporites sp. In this same locality, we collected borehole 1AS-32-AM as well as in outcrops of the Rio in situ seeds of Myrtaceae and Euphorbiaceae (genus Acre in the Late Miocene. Therefore, a younger age than Piranhea), indicating a typical floodplain (‘‘va´rzea’’) that proposed by Hoorn (1993) applies to well 1AS-4a- environment. AM. Niteroí, another well-known mammal locality, is located Second, we do not find C. vanraadshoovenii in any sam- on the right bank of the Lower Acre River, near the town ples at depths shallower than 48 m and find E. spinosus of Senador Guiomard in Acre. The lithology is dominated above 25 m. Our observations seem to agree with those by massive green to grey–green clayey sediments. About of Germeraad et al. (1968) and Muller et al. (1987) 90 cm from the low-water level is an intraformational con- (Fig. 13), who note the disappearance of Crassoretitriletes glomeratic clay, almost 40 cm thick, with mudballs and vanraadshoovenii at the base of or a little before the Aster- fish, crocodile, and turtle remains. About 2.4 m above the aceae zone in the Caribbean. This pollen species extends to low-water level is a rich fossiliferous bed. Gypsum crystals the top of the Pleistocene in Borneo and Nigeria. Lorente are disseminated in the clayey sediments and fill fractures (1986) shows that C. vanradshoovenii is still alive in some and fossil bones. Lignite and leaves are common in this parts of the tropics. site. Palynological samples were collected approximately Third, Hoorn (1993) concludes that there is no paly- 1 m above the low-water level. E. spinosus forms <1% of nological evidence of Late Miocene or Pliocene ages the pollen count. The assemblage includes M. annulatus, but mentions the presence of E. spinosus in the Crasso- Crototricolpites annemariae, Corsinipollenites oculusnoctis, retitriletes zone. Similarly, we associate E. spinosus and Psilatriletes sp., Psilatricolpites sp., Retitricolporites sp., Crassoretitriles with Fenestrites, which has been reported Cicatricosisporites sp., Illexpollenites sp., E. maristellae, to appear only in the Late Miocene and Pliocene (Ger- Verrumonoletes sp., Retimonocolpites sp., Striatricolpites meraad et al., 1968; Muller et al., 1987). Our observa- catatumbus, Mauritiidites franciscoi, Verrutriletes sp., Reti- tions seem to agree with the disappearance of triletes sp., Retitricolporites sp., Margocolporites venwijhei, Crassoretitriletes vanraadshoovenii at the base or a little K. waterbolkii, Polypodiaceoisporites sp., Echiperiporites before the Asteraceae zone. sp., Azolla sp., Bombacacidites sp., Echitriletes muellerii, The biozones established by Hoorn (1993) for western P. herngrenii, P. tertiaria, Psilaperiporites sp., Psilatriletes Amazonia, notably the Crassoretitriletes (assigned to the sp2., Psilatricolporites sp., Podocarpidites sp., and R. Middle Miocene) and Grimsdalea (Middle–Late Miocene), lorentae. thus should be used with some caution, because the biochron of the main biostratigraphic markers seems, on the 4.3. Palynology and biostratigraphical context basis of the inconsistency between different reports in different regions, to be temporally transgressional (Fig. 13). The palynomorphs at different sites can be used to indi- For example, if we use the palynological biozone criteria cate rough absolute ages (Fig. 13) and provide tentative of abundance/scarcity, we might conclude that some of correlations of surface localities and boreholes (Fig. 10). the Acre River outcrops are of different ages because Patos, Barranco da Elizete, and Niteroí all represent the E. spinosus occurrences vary from a representative 8% at same time interval in the Late Miocene according to the Barranco da Elizete to a scarce 1% at Niteroi and none presence of Echitricolporites spinosus that characterizes at Murici. E. spinosus should be abundant in the Late Mio- the base of the Asteraceae zone and the absence of pollen cene (consistent with a Late Miocene age for Barranco da species that indicate Pliocene and Pleistocene ages, such Elizete), and its scarcity or absence would suggest an older as Stephanocolpites evansii, Echitricolporites mcneillyi, and or younger age for Murici or Niteroi. However, Niteroi Alnipollenites verus. This age estimate is consistent with and Patos are the most representative and important local- that from the vertebrate assemblage in the same area. ities for Huayquerian (Late Miocene) mammals. Forcing 74 E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80

Fig. 13. Biochron of main palynologic biostratigraphic markers used in northern South America for the Middle and Late Miocene. Note the temporal overlap/differences that vary among authors. Note also the different ages proposed for the Grismdalea biozone, though E. Spinosus seems characteristic of the Upper Miocene. Sources of information: (1) Germeraad et al. (1968); (2) Silva (2002); (3) Hoorn (1993); and (4) Muller et al. (1987). Germeraad et al. (1968) investigated the Caribbean; Lorente (1986) and Muller et al. (1987) worked in Venezuela. These localities, which are rather distant from the present study region, provide some points of comparison. Hoorn’s (1993) work was in western Amazonia. different ages for these outcrops using the absence, pres- The pollen association recorded in the upper levels of ence, or scarcity of E. spinosus or Grimsdalea would thus borehole IAS-32-AM is dominated by Grimsdalea magna- lead to error. Although pollen biozones have been impor- clavata. This is not a living species; Germeraad et al. tant for recognizing the Miocene ages of the sediments in (1968) infer it is a palm with a marked adaptability to dif- Amazonia, we need to improve their definitions and cali- ferent habitats. In the fossil record, this species is restricted brations, because their current definitions do not have suf- to the Caribbean, Venezuela, Colombia, and Brazil. A high ficient stratigraphic sensitivity and thus cannot be used as abundance of its pollen probably characterizes the margins precise tools for separating spans of time within the Mio- of shallow floodbasin lakes (Hoorn, 1994a) or forest ele- cene. Instead, they can lead to incorrect age assignments ments (Wijninga, 1996). In addition, a high abundance of within the Miocene and, thus, miscorrelations of the out- P. pokornyi (Malpighiaceae), recorded in association with crops and borehole evidence. Grimsdalea magnaclavata, also suggests a forest environment near the area of deposition. 4.4. Paleoenvironmental inferences In the lowermost intervals of borehole IAS-32-AM, Crassoretitriletes vanraadshoovenii is dominant. This spe- According to Lorente (1986), sporomorph assemblages cies has botanical affinities with Lygodium microphylum that are rich in specimens but poor in species are character- (synonymous with L. scandens), a climber fern with living istic of alluvial plains. This combination of characteristics representatives in Guyana (botanical samples deposited in is observed in several borehole and outcrop samples. For the herbarium of the Missouri Botanical Garden) and Bra- instance, dominance by pollen of Gramineae, as observed zil (herbarium of the INPA-National Institute of Amazo- at Patos, suggests an alluvial plain depositional nian Research, Manaus, Brazil, where material collected environment. in Saõ Paulo state is stored). However, some claim this spe- E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80 75 cies now lives only in West Africa and southeast Asia (Lor- typical outcrops of Marinãme/Santa Isabel area in the ente, 1986). Caqueta´ River (Figs. 9 and 10). Because the Solimo˜es For- Swamps are indicated by the presence of C. vanraads- mation is subhorizontally or horizontally bedded, and no hoovenii (Schizaceae), and aquatic or wet environments paleorelief or strong vertical displacement of faulting has are suggested by Magnastriatites grandiosus (Pteridaceae), been described in this area, the topographic difference of V. usmensis (Polypodiaceae), Psilamonoletes tibui, Deltoi- 250 m separating the outcrop of Early Miocene sediments dospora adriennis (Pteridaceae), Chomotriletes minor, at Marinãme and the inferred correlative deposits in well Bombacacidites baculatus (Pachira aquatica), and Azolla IAS-4a AM, buried around 200 m deep, demand justifica- sp. (Hoorn, 1993; Collinson, 2002). tion (Fig. 14). The outcrops at Puerto Caiman and Buenos Returning to the pollen collected from the outcrops Aires in the Caqueta´ and Cotuhe´ rivers, as well as those along the Acre River, Patos shows a predominance of along the Colombian part of the Amazon, near Marinãme, Monoporopollenites annulatus (70%), which appears less have been correlated with the Grimsdalea zone (Middle– abundant at Niteroí (15%), indicating aquatic vegetation Late Miocene; Hoorn, 1993) (Figs. 9 and 10). Given the (grassland in floodplains and/or floating meadows; Hoorn, absence of concrete field evidence of paleorelief, differential 1994b). subsidence, or faulting, the lateral correlation between the In all four localities, spores (e.g., Echitriletes muellerii older Early Miocene sediments at Marinãme and the (Sellaginellaceae?), Azolla sp., K. waterbolkii (Cyathea- Middle–Late Miocene sediments cropping out at other cea), Psilatriletes sp., Verrumonoletes sp., Cicatricosispor- localities nearby is a problem. As we noted, Hoorn ites sp.) are abundant and indicate a wet or aquatic (1993) did not identify Early Miocene deposits in borehole environment. Corsinipollenites oculusnoctis (Onagraceae) 1AS-51-AM (Figs. 9, 10, and 14). In this borehole, the and Chomotriletes minor are also present, mainly at basement was reached 167 m below the surface, and a mid- Niteroí, suggesting an aquatic environment. In addition, dle Miocene age was assigned to the lowermost levels. If forest elements are represented by P. pokornyi, Illexpolle- the Early Miocene is not recorded in this well, as reported nites sp. (Aquifoliaceae), and Multimarginites vanderham- by Hoorn (1993), it either was never deposited or eroded menii (Acanthaceae) (Germeraad et al., 1968; Hoorn, before deposition of the Middle Miocene sequence. 1993; Collinson, 2002). The more feasible explanation is that the Early Miocene Overall, the predominance of both spores and pollen is not recorded in well IAS-51-AM because it is located on indicates an aquatic environment consisting of freshwater the Iquitos arch. The Early Miocene sediments should rest lakes and swamps. This inferred abundance of freshwater subhorizontally, like a plateau, and deepen generally to the lake and swamp elements supports deductions made from southwest, growing more deep in the direction of the depo- the fauna. The environment inferred in Acre state and center of the basin (wells IAS 4a–AM) and outcrop lateral- southern Amazonas from both vertebrates and pollen con- ly in the border/margin of the basin to the northeast in tent of the sediments of the Solimo˜es Group implies grass- Colombian territory (Marinãme-Santa Isabel area). If this land and gallery forests along rivers, swamps, and shallow proposition is correct, the Iquitos arch was an active struc- lakes, subjected to fluctuating water levels in a tropical to tural barrier during the Early Miocene in the Amazon wet–dry tropical seasonal climate. Basin, probably acting as a forebulge or area in which we might expect thin deposits or no deposition to that time. 5. Correlation problems However, the situation is more complex for the Late Miocene. Why did depositions continue in NW Brazilian 5.1. Northern Amazonia Amazonia but not in SW Colombia? After the deposition of the Marinãme Early Miocene sediments, part of Colom- The outcrops in Acre were correlated by Ra¨sa¨nen et al. bian Amazonia may have acted as a positive relief during (1995) with the sediments of NW Amazonia described by the Middle–Late Miocene, but subsidence continued in Hoorn (1993, 1994a,b). As we have noted, it appears that Brazilian Amazonia and southernmost Colombian Amazo- the chronology proposed by Hoorn (1994b), based on pal- nia. This scenario could account for the different ages of ynological studies of boreholes and outcrops, contains the sediments but would exclude the possibility of marine some inconsistencies in the correlation of some outcrops transgressions reaching western Amazonia from the Carib- with the core sequences. Hoorn’s (1994b) five palynological bean Sea, through the Colombian Llanos, in the Middle or zones cover the time span between the Early Miocene and Late Miocene (cf. Hoorn, 1993, 1994b), because the north- Middle–Late Miocene ( 23 to 10 Ma). Notably, she cor- ernmost part of the Colombian Amazon lowlands would related the outcrop at Marinãme/Santa Isabel area in the suffer uplift during the Middle–early Late Miocene. So Caqueta´ River (Fig. 9) with the lowermost levels of bore- what happened with the Iquitos arch at this time? Appar- hole 1AS-4a AM (263.5–181.8 m depth; assigned to the ently, the arch was overlapped by tertiary sediments during Retitricolporites and Psiladiporites–Crototricolpites zones; the Middle Miocene–Late Miocene (150 m of Middle–Late Early Miocene), located approximately 300 km to the Miocene deposits in wells IAS-51-AM); in this case, the south. However, the Early Miocene was not recorded in forebulge area suffered drastic position and behavior borehole IAS-51-AM, nearly 150 km to the east from the changes, suffered subsidence in the area of the Iquitos arch, 76 E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80

Fig. 14. Another view of sediment positions and correlation in the terrain related to the sea level. The correlation between the Marinãme unit and the early Miocene deposits of the IAS-4a represent a difference of more than 200 m, almost equal to the well depth. Note the absence of Early Miocene sediments in well IAS-51-AM, indicating a hiatus or no deposition period in the section at around 10 Ma. and migrated east. At present, these remain hypotheses; we 1993) (Fig. 1A). Rasanen et al. also forced a Late Miocene need more data to draft a more concrete structural scenar- age (Serravalian–Tortonian) on the hypothetical seaway. io, particularly for the area east of the Iquitos arch. However, the deposits in Acre yield a Late Miocene fossil However, it is important to note that our palynological assemblage (Latrubesse, 1992; Latrubesse et al., 1997), data from borehole IAS-32-AM near the area described by indicating Huayquerian SALMA dating of 9–6.5 Ma Hoorn (1993) suggests that Late Miocene deposition (Flynn and Swisher, 1995; Cione et al., 2001). In contrast, occurred in northern Amazonia, west of the Iquitos arch the marine incursions postulated for the sediments of the and in Acre state. The difficulties previously noted prevent Pebas Formation in NW Amazonia are dated to the Mid- the correlation of the deposits of the Solimo˜es Formation dle Miocene or early Late Miocene (older than 11 Ma; throughout Amazonia, particularly when trying to differen- Hoorn, 1993), indicating they are at least 2.5 Ma older than tiate units within the Miocene. To strengthen such tempo- the Acre sediments. This correlation, suggested by Ra¨sa¨nen ral calibrations, a combined stratigraphic approach using et al., appears incorrect, despite the difficulties noted vertebrate paleontology is desirable. regarding Hoorn’s pollen ages (1993, 1994a,b). Ra¨sa¨nen et al. (1995) suggest that the mammalian fauna 5.2. Southwestern Amazonia in Acre state is not reliably dated and may be Middle Mio- cene, not Late Miocene. On the contrary, our contempora- In trying to justify an intracontinental seaway, Ra¨sa¨nen neous and subsequent work has significantly strengthened et al. (1995) correlate the outcrop of the Solimo˜es Forma- the basis for placing this fauna within the Late Miocene. tion in Acre with the marine incursions proposed by Hoorn Notably, support for a Late Miocene age is strengthened (1993, 1994b) in northwestern Amazonia and others in the by the pollen content of the key vertebrate sites of Patos Chaco Basin (Marshall and Sempere, 1993; Marshall et al., and Niteroi, which contain Echitricolpites spinosus, consis- E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80 77 tent with the Huayquerian age established for the macro- nological record and posttransgression environment fossils collected from the area (Fig. 10). On the basis of between the fossiliferous levels of the Solimo˜es Formation the faunal assemblage, the sediments in Acre can be corre- in SW Amazonia and the fluvial sediments of the Ituza- lated with the Urumaco Formation in Venezuela, which ingo´/Kiyu´ formations in the Parana´–La Plata Basin is thus was deposited in a marginal environment and also is con- postulated (Cozzuol, 1993; Cione et al., 2001). The sedi- sidered Huayquerian because of its fossil vertebrate con- ments of the Solimo˜es Formation described by Ra¨sa¨nen tent and its temporal correlation with the foraminifera et al. (1995) and us in Acre thus correlate with the Late zonation of the Caribbean zone (Dias de Gamero, 1996; Miocene posttrangression sediments represented by the Linares, 2004) (Fig. 10, Table 1). Ituzaingo´ Formation in the Parana´ Basin and the Urumaco A further difficulty regarding the connection with the Formation in Venezuela, not with the end of Middle Mio- South Atlantic across Bolivia and the Parana Basin pro- cene transgression (Fig. 1B). posed by Ra¨sa¨nen et al. (1995) is that this proposal corre- In conclusion, the Early and the Middle–early Late lates the Acre sediments with the Yecua Formation. The Miocene are not recorded outcropping in SW Brazilian Yecua Formation in the southern Bolivian plains indicates Amazonia, so we cannot discuss an imaginary paleoscenar- the northernmost limit of the Middle Miocene transgres- io to this time in the region. Additional information from sion within the Parana Basin (Entrerrian transgression; wells of the old Coal Project of CPRM and from the Ram- Marshall et al., 1993). This unit has fossil mammals from oń Formation, a unit of probable older tertiary age on the the Chasicoan mammal age, which is Middle Miocene border of Brazil and Peru, eventually may shed some new (>10 Ma) (Marshall and Sempere, 1993; Marshall et al., light on older tertiary records in SW Brazilian Amazonia. 1993). None of the fossil vertebrates recorded in the Yecua Formation has been recorded in the Solimoes Formation in 6. Southwestern Amazonia during the Late Miocene SW Amazonia. However, largely correlative with the Yec- ua Formation are the sediments of the Entrerrian trans- In light of the available evidence, we propose a new gression, recorded across much of southern South paleoenvironmental reconstruction for SW Amazonia dur- America as the Parana´ Formation in NE Argentina and ing the Late Miocene (Fig. 1B). As we have discussed, extending into southern Brazil (as the Mioceno de Pelotas), much of the evidence of marine influences during the Mio- Uruguay (Camacho Formation), and Patagonia (Puerto cene comes from NW Amazonia. Several authors have Madryn and correlated units). Abundant and spectacular proposed that occasional Early–Middle Miocene marine fossils, including bivalves, gastropods, and marine mam- incursions from the Caribbean reached as far south as mals, clearly indicate the marine nature of these sediments 2°S (Hoorn, 1993; Vonhof et al., 1998). Stable isotope (Cozzuol, 1993; Martinez and del Rio, 2002). The mini- studies could indicate that the marine incursions, if they mum age obtained from the marine outcrops in Patagonia existed at all, were weak, with the seawater component was determined as approximately 10 Ma on the basis of diluted by freshwater (Vonhof et al., 1998). Wesselingh 86Sr/87Sr 87 analysis on mollusks (Scasso et al., 2001) et al. (2002) report mainly freshwater molluscs in the Pebas and should be around 7Ma in the Chaco–Parana Basin Formation, the part attributed by palynology to the Mid- (Hernandez et al., 2005). Nevertheless, new discussions dle Miocene of the Solimoes Formation in this region. remain open about the age and nature of the marine depos- Also, in a more recent study by Kaandorp et al. (2006) its in southern Bolivia. only freshwater mollusks were recorded in outcrops of The subsequent regression phase is marked in the south- the upper Solimo˜es Basin, including some localities ern Parana´ Basin by the deposition of fluvial sediments of described by Hoorn (1994a). Ostracods in the upper Soli- the Ituzaingo´ Formation, possibly as a response to a fall in mo˜es area could indicate a brackish environment sea level at the Serravalian–Tortonian boundary. (Munõz-Torres et al., 2006). However, ostracods found The Ituzaingo´ Formation occurs along the Parana´ River in outcrops of the Tarauaca´ River, near the border of in Entre Rios Province, Argentina, and the correlative Amazonas and Acre states, indicate freshwater environ- Kiyu´ Formation in Uruguay bears a vertebrate assemblage ments in the area too (Feijo´ Ramos, 2006). Atypical mar- with strong affinities with the Acre fauna (Cione et al., ine fossil associations (vertebrates or invertebrates) 2001; Perea et al., 1994), clearly dating from the Huayque- previously were recorded in the Amazon, but no evidence rian SALMA (Fig. 10, Table 1). During the Late Miocene, of marine transgressions has been reported in NW Amazo- the Tariquia Formation was deposited in Bolivia, which nia during the Late Miocene. However, we recognize that should correlate with the deposits described herein and some inconsistencies remain unresolved regarding the pub- by Ra¨sa¨nen et al. (1995) in Acre. The Tariquia Formation lished pollen ages for this region (Hoorn, 1993, 1994a,b), was deposited in a fluvial continental environment between and some Miocene ages may be subject to future adjust- 8 and 6 Ma (Moretti et al., 1996). ment once an overall regional correlation scheme has been This Acre fauna thus postdates the Chasicoan mammals established (Figs. 10 and 13). found in deposits dating from the time of the marine trans- To establish the regional conditions during deposition of gression, or the Middle Miocene–early Late Miocene in the the Solimo˜es Formation, it is necessary to consider the evo- case of the Yecua Formation record. A synchronous chro- lution of the northern and central Andes (Fig. 1A). The 78 E.M. Latrubesse et al. / Journal of South American Earth Sciences 23 (2007) 61–80

first influence of a rising Eastern Cordillera in Colombia 6.5 Ma) previously deduced for the vertebrate fauna in appears at around 12 Ma (Guerrero, 1997). Sediments these sediments. A terrestrial wetland environment is indi- derived from the northern Andes, with the rich fossil fauna cated (Fig. 1B), represented by marshes, shallow lakes, and of La Venta ( 13–11 Ma), were deposited across the Mag- canopy forest along fluvial channels, consistent with the dalena Basin (La Honda Formation; Kay et al., 1997). sedimentary facies present. The water and sediment sup- The evolution of SW Amazonia reflects the evolution of plies for this system came from the Andes, forming a vast, the central Andes, where the Eastern Cordillera likely expe- highly unstable, hyperavulsive river system or megafan sys- rienced uplift and erosion between 27 and 5 Ma (Late Oli- tem similar to the Quaternary Chaco environment and the gocene–end of the Miocene) (Nobret et al., 1996), Neogene fluvial systems in the Ganges plain of northern resulting in an influx of sediments to the Amazon foreland India. basin, which led to the deposition of the lower part (not The uppermost levels of the Solimo˜es Formation have exposed in Acre) of the Solimo˜es Group. The cratonic areas been stratigraphically correlated with the Mesopotamian east of the foreland basin also acted as a sediment source beds of Argentina (lowermost levels of the Ituzaingo´ For- (Hoorn, 1993). The fastest uplift and deformation in the mation) and Uruguay (Kiyu Formation), as well as with central Andes occurred in the late Miocene (e.g., Coudert the fossiliferous Urumaco Formation from Venezuela. A et al., 1995; Jordan et al., 1983; Sebrier et al., 1988). After prior suggestion (Ra¨sa¨nen et al., 1995) that these sediments 10 Ma, debris accumulated in the foreland basin, and the were deposited in a tidal marine or estuarine environment sub-Andean fold-and-thrust belt developed (Gubbels is strongly refuted, because of the inconsistencies in the sea- et al., 1993). We infer that the sedimentary response to these way environmental interpretation and stratigraphic mis- events was the development in SW Amazonia during the takes committed by those authors when they temporally Huayquerian/Mesopotamian SALMA, marking the late correlate the Solimo˜es sediments outcropping in southwest- Tortonian and early Messinian stages, of a complex terres- ern Brazilian Amazonia with sedimentary units in the Par- trial sedimentary system. At this time, SW Brazilian ana Basin and northern Amazonia. Amazonia was connected directly to the Andes, and a megadepositional system, formed by avulsive fluvial belts Acknowledgements entering and crossing a large floodbasin, deposited at least the uppermost levels of the Solimo˜es Formation (Fig. 1B). We thank our colleagues from the Universidade Federal Large depositional systems, formed by river-like megafans do Acre, Rio Branco – J.P. Souza Filho, A. Ranzy, R. Ne- (similar to but in a wetter environment than the modern gri, J.C. Bocquentin, and E.G. Silva – for discussions and Chaco and Indogangetic depositional systems) sourced many years of collaborative fieldwork. CNPq (Conselho from the Andes, spread onto the subsiding plain formed Nacional de Pesquisas-Brazil) provided financial support, by shallow lakes, swamps, and fluvial belts abandoned by and CAPES (Coordenaçaõ de Aperfeiçoãmento de N´ıvel avulsion. At this time, the modern Ucayali and Maranõn– Superior, Brazil) funded a research fellowship for S. Silva. Huallaga basins did not exist, and the predominant drain- We also thank CPRM (Geological Survey of Brazil) for age thus was eastward from the Andes. The Divisor ranges providing samples for pollen analyses and Marıá Ineˆs Feijo´ seem to have formed a low, positive relief but were unable Ramos from Museu Paraense Emilio Goeldi, Belem, for to act as an effective drainage divide, transected as they were fossil invertebrate identifications. We especially thank Ra- by the fluvial systems and surrounded but not covered by jiv Sinha, Rick Madden, David Bridgland, and Rob West- the Late Miocene sediments (Latrubesse and Rancy, 2000). away for critical suggestions that improved the manuscript. The climate during the Late Miocene was wet tropical This paper is a contribution to the IGCP 518 project ‘‘Flu- with a dry season. Some lakes were probably slightly saline, vial sequences as evidences for landscape and climatic evo- as indicated by stable isotopic analyses of molluscs (Von- lution in the Late Cenozoic’’. hof et al., 1998). However, aridity was weak and insuffi- cient to produce calcareous soils (calcretes) or evaporites. 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