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Paranyctoides species (Late Cretaceous Eutherian Mammal)



From: Ben Creisler
bcreisler@gmail.com


A new online paper:

Marisol Montellano, Richard C. Fox & Craig S. Scott (2013)
Species Composition of the Late Cretaceous Eutherian Mammal Paranyctoides Fox.
Canadian Journal of Earth Sciences (advance online publication)
DOI: 10.1139/cjes-2012-0184
http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2012-0184#.UUiirxzvtcQ

Although the known record of Mesozoic eutherian mammals has been
significantly enriched in in recent years, early eutherian evolution
is still not well understood. Among the more controversial of Mesozoic
eutherians is Paranyctoides Fox, which was described in 1979 from the
Judithian Dinosaur Park Formation, Alberta, Canada. It is a rare taxon
and there has been identified in only a few other North American Late
Cretaceous local faunas since. Within the past decade, dental and
gnathic remains discovered in Central Asia have also been referred to
Paranyctoides, thereby expanding the geographic range of the genus
substantially and making it the only Late Cretaceous eutherian
ostensibly occurring in both continents. As a result of our detailed
study of Paranyctoides, however, we find that the Central Asian
species lack the diagnostic characters of Paranyctoides and must be
referred to other taxa. We conclude that this genus was limited to
North America, ranging from Aquilan to Lancian time, and accordingly
we recognize as valid only the followingspecies: Paranyctoides
sternbergi (Judithian, Alberta), P. maleficus (Aquilan, Alberta),
Paranyctoides Wahweap sp. A and sp. B (Judithian, Utah), Paranyctoides
Kaiparowits sp. A and sp. B (Judithian, Utah). Another purported
species of Paranyctoides, P. megakeros, from the Lancian of Wyoming,
is a junior synonym of Alostera saskatchewanensis.