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Phylogeny of South American Late Cretaceous mammals



From: Ben Creisler
bcreisler@gmail.com


A new online paper:


Alexander O. Averianov, Thomas Martin &  Alexey V. Lopatin (2013)
A new phylogeny for basal Trechnotheria and Cladotheria and affinities
of South American endemic Late Cretaceous mammals.
Naturwissenschaften (advance online publication)
DOI: 10.1007/s00114-013-1028-3
http://link.springer.com/article/10.1007/s00114-013-1028-3


The endemic South American mammals Meridiolestida, considered
previously as dryolestoid cladotherians, are found to be
non-cladotherian trechnotherians related to spalacotheriid
symmetrodontans based on a parsimony analysis of 137 morphological
characters among 44 taxa. Spalacotheriidae is the sister taxon to
Meridiolestida, and the latter clade is derived from a primitive
spalacolestine that migrated to South America from North America at
the beginning of the Late Cretaceous. Meridiolestida survived until
the early Paleocene (Peligrotherium) and early Miocene (Necrolestes)
in South America, and their extinction is probably linked to the
increasing competition with metatherian and eutherian tribosphenic
mammals. The clade Meridiolestida plus Spalacotheriidae is the sister
taxon to Cladotheria and forms a new clade Alethinotheria.
Alethinotheria and its sister taxon Zhangheotheria, new clade
(Zhangheotheriidae plus basal taxa), comprise Trechnotheria.
Cladotheria is divided into Zatheria (plus stem taxa, including
Amphitherium) and Dryolestida, including Dryolestidae and a
paraphyletic array of basal dryolestidans (formerly classified as
“Paurodontidae”). The South American Vincelestes and Groebertherium
are basal dryolestidans.