INVESTIGADORES
MARSICANO Claudia Alicia
artículos
Título:
Strengthening Western Gondwanan correlations: A Brazilian Dicynodont (Synapsida, Anomodontia) in the Middle Triassic of Namibia
Autor/es:
ABDALA, FERNANDO; MARSICANO, CLAUDIA; SMITH, ROGER; SWART, ROGER
Revista:
GONDWANA RESEARCH
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2013 vol. 23 p. 1151 - 1162
ISSN:
1342-937X
Resumen:
Terrestrial Middle Triassic strata occur throughout continental Africa and are particularly well exposed in
South Africa, Tanzania, Zambia, and Namibia. The youngest age for all these African deposits is widely accepted
as early Middle Triassic (Anisian). Fossils collected recently from the uppermost strata of the upper
Omingonde Formation in Namibia highlighted the presence of Chiniquodon, a carnivorous cynodont previously
only found in Ladinian-Carnian aged rocks of South America. In addition, work in progress indicates
that a large archosaur, originally reported as Erythrosuchus, also discovered from levels close to the top of
this unit, is in fact a rauisuchian, a group of archosaurs well known from Ladinian-Carnian beds of southern
South America. Here we present the first record of the tuskless dicynodont Stahleckeria potens from the top of
the upper Omingonde Formation in central Namibia. This taxon was up until now only known from the
Ladinian Dinodontosaurus Assemblage Zone of the Santa Maria Formation in southern Brazil. Thus, compelling
evidence for a Ladinian age for the upper levels of the upper Omingonde Formation is provided by two
therapsid and one archosaur taxa. The tetrapod fauna of the upper Omingonde Formation partially fills the
gap of the well-documented hiatus (Ladinian gap), prevalent throughout the Karoo basins of south and central
Africa. The presence of the same therapsid taxa in the Namibian Waterberg Basin and the Paraná Basin of
Brazil during Middle Triassic suggests that these basins were biogeographically linked through a series of
interconnecting lowlands, with no major ecological, climatic and/or physical barriers.