Recent Topics Posters
Leme, Elton , Brown, Gregory K. , Dilcher, David , Bernardes-de-Oliveira, Mary , Siqueira, José , Sales, Alexandre .
Protananaceae, a new fossil monocot family from the Lower Cretaceous, Santana Formation, northeastern Brazil.
The new fossil angiosperm family Protananaceae is described on the basis of the new morpho-taxon Protananas lucenae, representing an extinct putative lineage of monocots from the Lower Cretaceous of the Crato Member (100-110 mybp) of the Santana Formation, vicinity of Santana do Cariri, Ceará, northeastern Brazil. The holotype consists of a carbonized compression and impression in limestone of a well preserved densely strobilate inflorescence in apparent post-floral stage, and the upper portion of the floral scape which is almost completely covered by a leaf-like scape bract. Traditional morphological methods, scanning electron microscopy, x-ray, and tomography were used to evaluate the holotype. The character combination: strobilate, ellipsoidal inflorescence with conspicuous suborbicular bracts surrounding its base, apparent epigynous flowers, abundance of resin-like substance in scape, scape bract, and floral tissues, and the leaf-like scape bract with pronounced parallel nerves slightly convergent toward apex, bearing fragments of peltate trichomes along the intercostal area, do not permit placement of Protananaceae within any extant angiosperm lineage. However, the unusual set of features suggest a monocot affinity, possibly basal in the Poales (sensu APG 2003) near Bromeliaceae. The investigation was augmented by two additional collections, consisting of inflorescence impressions in limestone, which represent the paratypes.
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1 - Herbarium Bradeanum, Caxia Postal 15005, Rio de Janeiro, RJ, 20031, Brazil
2 - University of Wyoming, Department of Botany, 3165, 1000 E University Avenue, Laramie, Wyoming, 82071, USA
3 - University of Florida, Florida Museum of Natural History, Po Box 117800, Gainesville, Florida, 32611-7800, USA
4 - Universidade de São Paulo, Instituto de Geociéncias, Rua do Lago 562, Cid. Universitária, São Paulo, SP, 05508-080, Brazil
5 - Colegiadop dé Engenharia Agricola e Ambiental, UNIVASF, Ave. Tancredo Neves, 100, Centro, Petrolina, PE, 56306-410, Brazil
6 - Universidade Regional do Cariri, Museu de Palenontologia, SanSantana do Cariri, CE, 63190-000, Brazil
Presentation Type: Recent Topics Poster
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM