fossils

Footprint of strange dinosaur found in Alaska

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Vasika
Udurawane

Writer
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Julio
Lacerda

Staff Artist and Writer
Therizinosaurs are among the most unorthodox of dinosaurs. They have a big belly, short legs and tail, a long neck and a set of immense flattened claws to help them manipulate branches. Despite the majority being from Asia, tantalizing remains have surfaced from the unlikeliest of places.

Sometimes, a dinosaur’s footprints can tell us a lot more about the animal than its physical bones. In the year 2012, a strange new find was published in the June edition of the scientific journal Palaois by a team comprised of Dr. Anthony Fiorillo, curator of Earth Sciences at the Perot Museum of Nature and Science in Dallas, and his colleague Thomas Adams.


The discovery was a trackway of a dinosaur found in Alaska’s Denali region in rocks from the Lower Cantwell Formation. This rock bed dates back to the Late Cretaceous, about 70 million years ago, close to the end of the dinosaur age. The trackway belonged to an animal that the team did not expect to see on their expedition.


It was the track of a big maniraptoran theropod, the line of dinosaurs that gave rise to birds, and included such animals as the famous “raptor” dinosaurs like Deinonychus. The animal that left the footprint behind though, was much bigger – a therizinosaur.


Fiorillo and team were astounded by the discovery, for therizinosaurs had never been found this far north before. It was identifiable as a therizinosaur from the tell-tale feature of four outward-pointing toes, a feature that only two groups of theropods have. These feet were built for bearing a great deal of weight, a good feature in a possibly very large herbivorous animal.


The researchers also studied the area in which the remains were found. At the time, this area of Alaska was full of other dinosaurs too, as the numerous duckbill tracks from the area suggest. According to Fiorillo, it was probably an area which these big herbivores visited while migrating. This also gives us a clue as to how such a dinosaur could end up at such a high latitude. It is probable that the therizinosaurs or their ancestors migrated from the Baikal region via the Bering Land Bridge, and into Alaska. Fiorillo and team have constructed a map that shows the migration in their Palaois paper to explain the presence of this Asian dinosaur in North America.


As a group, the therizinosaurs only began surfacing during the 20th Century, and their fossils stunned researchers all over the world. Among the first to be revealed was Therizinosaurus itself, a gigantic creature from the Late Cretaceous of Mongolia.


It was taller than a giraffe and stretched at least 10 meters in length. The beast weighed in at  5.5 tons, making it one of the biggest of all theropods. It rounded off this imposing appearance with a long, erect neck for browsing on leaves and a big stomach for digesting plant matter. A coat of bird-like feathers covered the huge animal’s body, just as it did to other maniraptorans and many other theropod families. It also had a set of lethal-looking albeit flattened claws, probably for defence and also for manipulating branches. It was a herbivorous dinosaur derived from much more predatory ancestors, which at the time of discovery, was a first in paleontology.


As more fossils surfaced from both Asia and North America, the secrets of this family of oddballs were uncovered and finally they were given their place in the dinosaur family tree. The new Alaskan find not only adds to their geographic range but also adds a new member into the ranks of an already weird group of dinosaurs.

3986b46bb4f35aa1ff4d42167a12e0fc

Vasika
Udurawane

Writer


http://sulc.us/f7tr0
http://www.eartharchives.org/articles/footprint-of-strange-dinosaur-found-in-alaska/