Portal de Periódicos da CAPES

Evidence of early evolution of Australidelphia (Metatheria, Mammalia) in South America: phylogenetic relationships of the metatherians from the Late Palaeocene of Itaboraí (Brazil) based on teeth and petrosal bones

2010; Oxford University Press; Volume: 159; Issue: 3 Linguagem: Inglês

10.1111/j.1096-3642.2009.00577.x

1096-3642

Sandrine Ladevèze, Christian de Muizon,

Fish biology, ecology, and behavior

New metatherian petrosal bones from the mid to Late Palaeocene of Itaboraí, belonging to three morphotypes (VI, VII, and VII), are formally described and compared to fossil and extant taxa known by their auditory region. An attempt at assigning petrosal types to tooth-based taxa from Itaboraí was made by combining parsimony and morphometric methods. The first large scale phylogenetic analysis of the Itaboraían metatherians, involving basicranial and dental characters in a larger number of taxa, is provided here and is at the basis of a systematic revision of the metatherians from Itaboraí. The combination of morphometric and cladistic analyses helps in understanding the affinities between the petrosals and the tooth-based taxa. The metatherians from Itaboraí were taxonomically diverse, belonging to each of the most important radiations in marsupial evolutionary history (Didelphimorphia, Paucituberculata, Eometatheria). The inclusion of Palaeocene taxa in the crown group Marsupialia and above all in the Eometatheria radiation points to an early emergence of these clades in South America and corroborates the main molecular hypotheses.