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Cretaceous mammal lineages survived into Cenozoic in South America (resend)



From: Ben Creisler
bcreisler@gmail.com


I sent this item yesterday but it was lost in cyberspace (a problem I
have noticed with a number of postings lately). I don't know if the
issue is gmail or the DML...

===

A new non-dino paper that may be of interest:


Nicolás R. Chimento, Federico L. Agnolina & Fernando E. Novas (2014)
The bizarre 'metatherians' Groeberia and Patagonia, late surviving
members of gondwanatherian mammals.
Historical Biology (advance online publication)
DOI:10.1080/08912963.2014.903945
http://www.tandfonline.com/doi/full/10.1080/08912963.2014.903945#.U1aDqPldXeI



Cenozoic mammalian faunas from South America contrast with those of
the other continents by the great diversification of metatherian
mammals. Among the later, a wide range of morphological disparity have
been reported, and several bizarre mammals have been assigned to such
clade, based mainly on biogeographical grounds. Outstanding examples
of bizarre mammals referred to as Metatheria are the Eocene Groeberia
and the Miocene Patagonia. Recent discoveries indicate that South
America possessed a more diverse faunal composition than previously
thought, and it became evident that many Mesozoic holdovers (e.g.
australosphenidans, gondwanatherians and dryolestoids) surpassed the
K/T boundary, thus forming part of the Cenozoic faunas. The Cenozoic
taxa Patagonia and Groeberia exhibit several similarities with the
Gonwanatheria, including rodent-like jaws with enlarged incisives,
molariform cheek-teeth, anteriorly extended masseteric fossa and
palinal mastication among other features. The inclusion of
Gondwanatheria, Patagonia and Groeberia within an abarcative
phylogenetic analysis resulted in close phylogenetic relationships
among these taxa. Such hypothesis indicates that Cretaceous relics in
the Cenozoic of South America were more diversified than previously
thought.