Martínez, Camila , Madriñán, Santiago , Zavada, Michael , Jaramillo, Carlos .
Tracing the fossil pollen record of Hedyosmum (Chloranthaceae), a basal angiosperm.
The Chloranthaceae represent one of the oldest lineages within the angiosperms. Hedyosmum is the only Neotropical genus in the family with 45 species. The fossil record shows that the first appearance of Hedyosmum-like fossils was in the Early Cretaceous (~125 Ma), but that there is a gap of 70 Ma during the Paleogene before a possible new record of Hedyosmum (Clavainaperturites microclavatus) appears in the Early Miocene. The main objective of this study is to determine the relationship between the fossil C. microclavatus and extant representatives of the genus Hedyosmum using light, scanning and transmission electron microscopy. Given the high morphological affinity of the pollen fossil with extant Hedyosmum it is concluded that C. microclavatus is indeed a representative of Hedyosmum, and that the genus was present in Central and South America before the emergence of the Isthmus of Panama and the rise of the Andean cordillera. Additionally, we present a dated phylogeny of the family, with nodes calibrated using the extensive fossil record of Chloranthaceae that supports the ancestry of the lowland taxa.
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Laboratorio de Botánica y Sistemática
1 - Universidad de los Andes, Departamento de Ciencias Biológicas, Laboratorio de Botánica y Sistemática, Apartado Aéreo 4976, Bogotá, DC, Colombia
2 - East Tennessee State University, Department of Biological Sciences, P.O. Box 70703, Johnson City, TN, 37614, United States
3 - Center for Tropical Paleoecology and Archeology, Smithsonian Tropical Research Institute, Box 0843-03092 & # 8232, Balboa, Ancon, 34002-0948, Republic of Panama
Presentation Type: Poster:Posters for Sections
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM