New Specimens of oviraptorid Nemegtomaia from Mongolia

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com

New in PLoS ONE:

Fanti, F., Currie, P.J. & Badamgarav, D. (2012)
New Specimens of Nemegtomaia from the Baruungoyot and Nemegt
Formations (Late Cretaceous) of Mongolia.
PLoS ONE 7(2): e31330
doi:10.1371/journal.pone.0031330
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031330

Two new specimens of the oviraptorid theropod Nemegtomaia barsboldi
from the Nemegt Basin of southern Mongolia are described. Specimen
MPC-D 107/15 was collected from the upper beds of the Baruungoyot
Formation (Campanian-Maastrichtian), and is a nest of eggs with the
skeleton of the assumed parent of Nemegtomaia on top in brooding
position. Much of the skeleton was damaged by colonies of dermestid
coleopterans prior to its complete burial. However, diagnostic
characters are recovered from the parts preserved, including the
skull, partial forelimbs (including the left hand), legs, and distal
portions of both feet. Nemegtomaia represents the fourth known genus
of oviraptorid for which individuals have been found on nests of eggs.
The second new specimen, MPC-D 107/16, was collected a few kilometers
to the east in basal deposits of the Nemegt Formation, and includes
both hands and femora of a smaller Nemegtomaia individual. The two
formations and their diverse fossil assemblages have been considered
to represent sequential time periods and different environments, but
data presented here indicate partial overlap across the
Baruungoyot-Nemegt transition. All other known oviraptorids from
Mongolia and China are known exclusively from xeric or semi-arid
environments. However, this study documents that Nemegtomaia is found
in both arid/aeolian (Baruungoyot Formation) and more humid/fluvial
(Nemegt Formation) facies.