Paleo File: Alectrosaurus

         The fossil record, although expansive and bursting-from-the-seams with material, is rather fragmentary. This can be observed time and time again with discoveries so fragmentary proper names are impossible to be attributed. The tomb that is Mongolia is a great reservoir of fossils, many quite well-preserved; however, along with the well-preserved specimens comes the fragmentary ones. Alectrosaurus is one of those fragmentary finds that struggles to shed light on the ecosystems of the prehistoric world, and of course Mongolia as well.

Only the right hindlimb was found on April 25th, 1925, by the Third Asiatic Expedition of the American Museum of Natural History. This find was not the first nor the last and a week later assistant Paleontologist, George Olsen, (the discoverer of the first specimen) found more material on the fourth of May. Nearly one hundred feet away from the initial specimen, he discovered a right humerus, two incomplete manual digits, and four fragmentary caudal vertebrae. These finds were sent back to the museum and prepared; however, more material was uncovered some time later. Fossils were then found in Outer Mongolia which included skull and shoulder fragments. Enough material to suggest how the animal may have appeared in life (Thanks to the laws of symmetry), still more material is needed to get a better picture of this animal.

Art and Copyright belongs to Sergey Krasovskiy

                 The material that was found suggests a Tyrannosauroid theropod of medium size and moderate build. Alectrosaurus may have reached lengths of up to twenty feet. Unlike other Tyrannosauroids, the superfamily leading to more advanced groups like Tyrannosauridae, the lengths of the tibia and femur are rather similar. The formation in which Alectrosaurus was found, called the Iren Dabasu Formation, suggests it may have lived in an area that also housed animals like Gigantoraptor, Bactrosaurus, and Gilmoreosaurus.

Art and Copyright belongs to Prehistoric Wildlife

Copyright belongs to BBC

Works Cited:

Holtz, Thomas R. Jr. (2011) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages, Winter 2010 Appendix.

Loewen, M.A.; Irmis, R.B.; Sertich, J.J.W.; Currie, P. J.; Sampson, S. D. (2013). Evans, David C, ed. "Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans". PLoS ONE 8 (11): e79420. doi:10.1371/journal.pone.0079420

Rothschild, B., Tanke, D. H., and Ford, T. L., 2001, Theropod stress fractures and tendon avulsions as a clue to activity: In: Mesozoic Vertebrate Life, edited by Tanke, D. H., and Carpenter, K., Indiana University Press, p. 331-336.

"Alectrosaurus." Alectrosaurus. Prehistoric Wildlife, n.d. Web. 17 Mar. 2016.

"Alectrosaurus Olseni - Palaeocritti - a Guide to Prehistoric Animals." Alectrosaurus Olseni - Palaeocritti - a Guide to Prehistoric Animals. Palaeocritti, n.d. Web. 17 Mar. 2016.

"Alectrosaurus Olseni - Palaeocritti - a Guide to Prehistoric Animals." Alectrosaurus Olseni - Palaeocritti - a Guide to Prehistoric Animals. Palaeocritti, n.d. Web. 17 Mar. 2016.
"Fossilworks: Alectrosaurus Olseni." Fossilworks: Alectrosaurus Olseni. Fossil Works, n.d. Web. 17 Mar. 2016.