Albertadromeus, new ornithopod from Cretaceous of Canada (free pdf)

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com

Another new dinosaur for today in the new issue of JVP. The pdf is open access.


Caleb Marshall Brown, David C. Evans, Michael J. Ryan & Anthony P.
Russell (2013)
New data on the diversity and abundance of small-bodied ornithopods
(Dinosauria, Ornithischia) from the Belly River Group (Campanian) of
Alberta.
Journal of Vertebrate Paleontology 33(3): 495-520
DOI:10.1080/02724634.2013.746229
http://www.tandfonline.com/doi/abs/10.1080/02724634.2013.746229#.UYm5ubXvtcQ


Relative to large-bodied dinosaurs, the diversity of small-bodied
dinosaurs from the Campanian of North America is poorly understood due
to a lack of well-preserved skeletons. We document the first
articulated remains, as well as the first cranial bones, of
non-iguanodontian ornithopods from the Belly River Group of Alberta.
The geologically oldest specimen consists of the posterior half of an
articulated skeleton from the middle unit of the Oldman Formation and
shares many anatomical features with the contemporaneous Orodromeus
makelai and the older Oryctodromeus cubicularis. A second, younger
specimen from the upper Oldman Formation is distinct from other
ornithopods in having a reduced distal portion of the fibula that is
fused to the anterior surface of the tibia; it is designated as the
type of a new taxon, Albertadromeus syntarsus, gen. et sp. nov.
Numerous isolated elements from small ornithopods from the Dinosaur
Park Formation are also identified, but cannot be assigned to the
generic level with confidence. Although small-bodied ornithopod
material is rare, their known postcranial material outnumbers those of
taphonomically equivalent and contemporaneous pachycephalosaurs, which
are known to be abundant and diverse due to their robust and
frequently recovered cranial domes. These findings suggest
considerable undiscovered diversity of small-bodied ornithopods, and
highlight biases against the preservation of small taxa in this
system.