CIG   05423
CENTRO DE INVESTIGACIONES GEOLOGICAS
Unidad Ejecutora - UE
artículos
Título:
Diversity, taphonomy, and palaeoecology of angiosperm during the Cenomanian-Coniacian in Southern Patagonia, Argentina
Autor/es:
IGLESIAS, ARI; ZAMUNER, ALBA; POIRÉ, DANIEL; LARRIESTRA, FERNANDO
Revista:
PALAEONTOLOGY
Editorial:
The Palaepntological Association
Referencias:
Lugar: Londres; Año: 2007 vol. 50 p. 445 - 466
ISSN:
0031-0239
Resumen:
Abstract: This paper describes the diversity, taphonomy and palaeoecology of angiosperm leaves that dominate a
palaeoflora of Cretaceous (CenomanianConiacian) age from the Mata Amarilla Formation in the Austral Basin,
south-west Patagonia, Argentina. Twelve morphotypes of angiosperm leaves are recognized based on foliar morphotype
analysis of more than 500 specimens. These were divided into six morphological groups based on major
architectural patterns. The relative dominance of these morphotypes, mode of preservation and relationship with
sedimentary facies were evaluated from two levels within the formation. This analysis identified two different plant
palaeocommunities. The lower, Marý´a Elena, level (MEL) was deposited in a marine coastal area on a subaerial delta
plain; the dominant angiosperm morphotypes preserved in it are group 1 (MA100) and group 2 (MA101, 102);
morphotypes MA109 and 110 are scarce but exclusive to this level. The upper, Mata Amarilla, level (MAL), accumulated
inland in flood-plain environments; the most abundant angiosperm morphotypes are groups 3 (MA103105),
4 (MA106) and 1 (MA100); morphotypes MA103105 and 108 are exclusive to this level. Comparisons with other
floras of similar age from Antarctica, Australia and New Zealand indicate that the Mata Amarilla flora has a slightly
higher morphological diversity of angiosperm leaves, providing the first evidence for an angiosperm-dominated early
Late Cretaceous macroflora in south-west Gondwana.