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Mon January 21, 2013
Dr. Darla Zelenitsky, University of Calgary – Feathered Dinosaurs
In today’s Academic Minute, Dr. Darla Zelenitsky of the University of Calgary reveals a find that is a first for North American paleontology.
Darla Zelenitsky is an assistant professor and the principal dinosaur researcher in the Department of Geoscience at the University of Calgary. Her research lab uses various approaches to reconstruct and examine changes in the biology and behaviors of extinct species. Her findings have be published in a number of peer-reviewed journals and she holds a Ph.D. from the University of Calgary.
Dr. Darla Zelenitsky – Feathered Dinosaurs
First discovered in the mid 1990s, feathered dinosaurs have had a great impact on our understanding of early feathers and the link between dinosaurs and birds. Unfortunately, these significant fossils have been restricted to only a few deposits in northern Asia and Germany. Recently however, my colleagues and I discovered feathered dinosaurs from an entirely different region -- the badlands of Alberta, Canada. These are the first feathered dinosaurs known from the Western Hemisphere. The specimens are of ornithomimids, a group of ostrich-like dinosaurs for which feathers were previously unknown.
We discovered the skeletons of a juvenile and two adult ornithomimids preserved with feathers. Our research shows that the plumage of ornithomimids changed during growth where wing-like structures developed on the forearms in older individuals. Our findings also reveal that ornithomimids are the most primitive dinosaurs with primordial wings. The presence of these wings only in adults suggests that these structures initially evolved for uses later in life, such as egg brooding or courtship.
Prior to our discovery, feathered dinosaurs were found primarily in fine sediments of ancient lakes and lagoons, whose quiet-water muddy environments were thought necessary to fossilize feathers. Our specimens, however, were preserved in sands of ancient flowing rivers, revealing that feathers can also fossilize in high energy environments. Even though most of the dinosaurs collected worldwide come from ancient river deposits, our specimens from Canada are the first feathered dinosaurs known from such sediments. We thus suspect that feathers have been overlooked in many specimens collected from ancient river deposits, and believe that our findings will lead to the discovery of many more feathered dinosaurs worldwide.