ISLAND (ANTARCTICA): ASSESSING THE GEOLOGICAL CONTEXT AND BOTANICAL AFFINITIES
ABSTRACT – Imbricate-leaved podocarps (Dacrydium s.l.) are the dominant conifer remains in the Upper Cretaceous and Cenozoic successions of King George Island, increasing its abundance in the post-Late Paleocene strata and maintained until the Early Oligocene times, with poor taphoflora registered i...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.463.5483 http://www.sbpbrasil.org/revista/edicoes/13_3/189a204_Paleogene Imbricate-Leaved.pdf |
| Summary: | ABSTRACT – Imbricate-leaved podocarps (Dacrydium s.l.) are the dominant conifer remains in the Upper Cretaceous and Cenozoic successions of King George Island, increasing its abundance in the post-Late Paleocene strata and maintained until the Early Oligocene times, with poor taphoflora registered in the last. However, a more precise taxonomic relationship of their remains was ever difficult given the fragmentary nature of the fossils and most known from ex situ material. In new field works and collections looking for the original levels, the recent phylogenetic approaches proposed and comparisons with extant floras have been applied to these fossils, and have helped to clarify their taxonomic status and their preferable association with the Upper Paleocene-Lower Eocene levels. The two kinds of foliage discussed here initiated the taxonomic revision of the Podocarpaceae related fossils on the island and attest to a modern affinity with Dacrydium vel Halocarpus and Dacrycarpus, which was in part proposed by previous works. Those genera comprise today an important component of the eastern Southern Hemisphere forests, and their occurrence in the Antarctic Peninsula areas during the Paleogene supports a broader distribution in the past and attests to the importance of the ancient Antarctic coastal areas in the modern distribution of the Podocarpaceae. |
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