Paleo File: Aviatyrannis

        Although small organisms tend to fossilize more complete than larger organisms, due to the increase of deterioration by environmental conditions on larger surface areas quicker, there are plenty of fragmentary organisms of a small stature. Take for instance; the theropod dinosaur, Aviatyrannis (Av-Eye-Ah-Tie-Ran-Is).

Material attributed to Aviatyrannis

           Uncovered exclusively, so far as science knows, in Portugal, the material was initially found in a lignitic coal seam within the Alcobaca Formation at Guimarota, which is near Leiria in Central Portugal. The Holotype, for which the specific name, jurassica, was attributed by Paleontologist, Oliver Rauhut, and subsisted of a right ilium. The ilium dated to the early Kimmeridgian stage of the Late Jurassic, about 155 million years ago. In 2003, Rauhut assigned a few more pieces to the genus including, a partial right ilium and right ischium.

Approximate Size

          The name, Aviatyrannis jurassica, translates to, “Tyrant Grandmother of the Jurassic” referring to the animal’s phylogenetic placement. Aviatyrannis is a very basal Tyrannosauroid, with the exception of Proceratosaurus, it is the most primitive and likely did not grow very large, with an estimated length of approximately 3-4 feet. Like with the majority of prehistoric flora and fauna, more material is needed before proper identification and visualization of the living organism can be appropriately realized.

Art and Copyright belongs to Frederik Spindler

Works Cited:

Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 100

"Aviatyrannis." Wikipedia. Wikimedia Foundation, n.d. Web. 24 Mar. 2016. <https://en.wikipedia.org/wiki/Aviatyrannis>.

"Aviatyrannis." Aviatyrannis. Prehistoric Wildlife, n.d. Web. 24 Mar. 2016. <http://www.prehistoric-wildlife.com/species/a/aviatyrannis.html>.

"AVIATYRANNIS : From DinoChecker's Dinosaur Archive." Dinochecker RSS. DinoChecker, n.d. Web. 24 Mar. 2016. <http://www.dinochecker.com/dinosaurs/AVIATYRANNIS>.
"Fossilworks: Aviatyrannis Jurassica." Fossilworks: Aviatyrannis Jurassica. Fossilworks, n.d. Web. 24 Mar. 2016. <http://fossilworks.org/?a=taxonInfo&taxon_no=68482>.