Tarchia armor and scales

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com

A new online paper:




Victoria M. Arbour, Nicolai L. Lech-Hernes, Tom E. Guldberg, Jørn H.
Hurum, and Philip J. Currie (2012)
An ankylosaurid dinosaur from Mongolia with in situ armour and
keratinous scale impressions.
Acta Palaeontologica Polonica (in press)
doi:10.4202/app.2011.0081
http://app.pan.pl/article/item/app20110081.html

A Mongolian ankylosaurid specimen identified as Tarchia is an
articulated skeleton including dorsal ribs, the sacrum, a nearly
complete caudal series, and in situ osteoderms. The tail is the
longest complete tail of any known ankylosaurid. Remarkably, the
specimen is also the first Mongolian ankylosaurid that preserves
impressions of the keratinous scales overlying the bony osteoderms.
This specimen provides new information on the shape, texture, and
arrangement of osteoderms. Large flat, keeled osteoderms are found
over the pelvis, and osteoderms along the tail include large keeled
osteoderms, elongate osteoderms lacking distinct apices, and
medium-sized, oval osteoderms. The specimen differs in some respects
from other Tarchia specimens, including the morphology of the neural
spines of the tail club handle and several of the largest osteoderms.