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Paranyctoides (Cretaceous eutherian mammal) taxonomy



From: Ben Creisler
bcreisler@gmail.com

A new online paper:

Alexander O. Averianov & J. David Archibald (2013)
Variation and taxonomy of Asiamerican eutherian mammal Paranyctoides.
Canadian Journal of Earth Sciences (advance online publication)
doi: 10.1139/cjes-2013-0051
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2013-0051#.UbXr1Pm1FcQ


A parsimony analysis of the distribution of 408 characters in 73 taxa
of Cretaceous eutherians and related taxa places three species of
Paranyctoides, the Asiatic P. quadrans and the North American P.
sternbergi and P. maleficus, into a monophyletic taxon supported by
three unambiguous synapomorphies. In this analysis P. quadrans has
three autapomorphies, but in the analysis using combined terminal
taxon for the entire sample of North American Paranyctoides two of
these autapomorphies (development of stylar cusps C and D on upper
molars) disappeared because these characters are also variably present
in the North American sample. The remaining autapomorphy of P.
quadrans, m3 shorter than m2, is known from a single specimen and also
may be affected by individual variation. The North American sample of
Paranyctoides cannot be clearly separated into distinct species on
morphological or morphometric grounds and is considered as
representing a single species, P. sternbergi Fox, 1979 (=P. maleficus
Fox, 1984, syn. nov.). It differs from the Asiatic P. quadrans (Nesov,
1993) only in having a sharp lingual ridge on p5 and m3 longer than
m2. Paranyctoides is the sister taxon to Zhelestidae; this clade is
supported by four unambiguous synapomorphies.