Tyrannosaurus Rex

Tyrannosaurus Rex

The Tyrannosaurus Rex, also known as the T-Rex, roamed the soils of the Earth millions of years ago. There have been fossils that can date back as early as 66-68 million years ago[1], which was during the upper Cretaceous Period. This dinosaur is commonly depicted as a large, bipedal carnivore, which is it. Tyrannosaurus Rex fossils measure to be approximately 40 feet in length[2], 15-20 feet in height[4], and 13 feet in width[3]. Scientists have estimated the Tyrannosaurus Rex to be approximately 6.8 metric tons (appx. 14,991 pounds)[13].

Aside from the Tyrannosaurus Rex's large dimensions, it carries a lot of other interesting traits as well. The dinosaur can be described as having a massive skull, large, powerful hind limbs, short forelimbs, and a long, heavy tail. With these traits, we are able to investigate the old debate on whether the Tyrannosaurus Rex was a predator or a pure scavenger. With its massive skull relative to its body (5 feet long)[4], it also had a relatively larger brain-to-body ratio when compared to other dinosaurs and reptiles, which suggests that it must've been smarter[5]. However, there was a controversy on how the massive brain doesn't identify the dinosaur as a predator, but more of a scavenger since its mass prevented the T-Rex from running as quick as small animals. Many scientists in the past have concluded that the T-Rex must have not been a fast runner due to its massive size and its femur to tibia ratio. The average pace of the Tyrannosaurus Rex was about 11 meters per second (or 24 miles per hour)[7]. Regardless of the speed, this debate is no longer taken seriously due to other factors that make up for its speed. Since the T-Rex was so large, it could easily scavenge or steal prey from any other predator[6]. The T-Rex was known to use their heightened sensory abilities to track and find its food sources.

The Tyrannosaurus Rex had an outstanding sensory ability; it was able to track movement from long distances with their enhanced ability to sense low frequency sounds[8]. Alongside with this ability, it also had rapid and coordinated eye and head movements along with an enhanced sense of smell[8], which can be explained by its relatively large olfactory bulbs[14]. The T-Rex was able to have a binocular range of 55 degrees, which can see as far as 3.7 miles away (comparing with a human, we can only see 1 mile away)[9][10][11][12]. These extraordinary abilities helped the Tyrannosaurus Rex detect its prey from far distances.

While surviving and searching for food, it was believed that the Tyrannosaurus Rex traveled in packs together. When scientists examined the dinosaur's feeding behavior, scientists Karl Bates and Peter Falkingham suggested that the T-Rex's bite force generated about 35,000 to 57,000 Newton of force with just their back teeth. There have been higher estimates made by different scientists such as professor Meers. Meers estimated that the bite of a T-Rex was approximately 183,000 to 235,000 Newtons[18]. The dinosaur could have been the strongest terrestrial animal ever lived [15][16][17]. Looking at other possible ways of feeding, there has been controversy on the use of the relatively small arms. Some scientists believe that the arms were used to hold onto struggling prey while being killed by its enormous jaw. On the other hand, some scientists believed this was a vestigial feature since short arms made it difficult to actually hold onto prey because the gripping force was simply not large enough[19]. From fossil examinations, the dinosaur's arms measured to approximately three feet long.

Classification:

KingdomAnimalia
PhylumChordata
OrderSaurischia
SuborderTheropoda
FamilyTyrannosauridae
SubfamilyTyrannosaurinae
TribeTyrannosaurini
GenusTyrannosaurus

References:

  1. Hicks, J. F.; Johnson, K. R.; Obradovich, J. D.; Tauxe, L.; Clark, D. (2002)."Magnetostratigraphy and geochronology of the Hell Creek and basal Fort Union Formations of southwestern North Dakota and a recalibration of the Cretaceous-Tertiary Boundary" (PDF). Geological Society of America Special Papers 361: 35-55.
  2. Hutchinson, J. R.; Bates, K. T.; Molnar, J.; Allen, V.; Makovicky, P. J. (2011). "A Computational Analysis of Limb and Body Dimensions in Tyrannosaurus rex with Implications for Locomotion, Ontogeny, and Growth". PLoS ONE 6 (10): e26037.
  3. "Sue's vital statistics". Sue at the Field Museum. Field Museum of Natural History. Archived from the original on September 29, 2007. Retrieved September 15,2007.
  4. Society, National. "Tyrannosaurus Rex, Dinosaur Pictures, Dinosaur Facts - National Geographic". National Geographic. N.p., 2016. Web. 23 Jan. 2016.
  5. Hurlburt, Grant S.; Ridgely, Ryan C.; Witmer, Lawrence M. (July 5, 2013) [This volume originated in a conference held on September 16-18, 2005, titled 'The Origin, Systematics, and Paleobiology of Tyrannosauridae,' and sponsored by the Burpee Museum of Natural History and Northern Illinois University]. "Chapter 6: Relative size of brain and cerebrum in Tyrannosaurid dinosaurs: an analysis using brain-endocast quantitative relationships in extant alligators". In Parrish, Michael J.; Molnar, Ralph E.; Currie, Philip J.; Koppelhus, Eva B. Tyrannosaurid Paleobiology (Life of the Past). Indiana University Press. pp. 134-154. ISBN 978-0-253-00947-0. Retrieved October 20,2013.
  6. Farlow, J. O. and Holtz, T. R. (2002). "The fossil record of predation in dinosaurs"(pdf). In Kowalewski, M. and Kelley, P.H. The Fossil Record of Predation. The Paleontological Society Papers 8. pp. 251-266.
  7. Hutchinson, J.R. (2004). "Biomechanical Modeling and Sensitivity Analysis of Bipedal Running Ability. II. Extinct Taxa" (PDF). Journal of Morphology 262 (1): 441-461.
  8. Witmer, Lawrence M.; Ridgely, Ryan C. (September 2009). "New Insights Into the Brain, Braincase, and Ear Region of Tyrannosaurs (Dinosauria, Theropoda), with Implications for Sensory Organization and Behavior". The Anatomical Record 292 (9): 1266-1296.
  9. Emily, John (July 3, 2006). Supersight for a Dino King. Retrieved July 7, 2006.
  10. Stevens, Kent A. (April 1, 2011) The Binocular Vision of Theropod Dinosaurs. Retrieved July 29, 2013.
  11. Stevens, Kent A. (June 2006). "Binocular vision in theropod dinosaurs". Journal of Vertebrate Paleontology 26 (2): 321-330.
  12. Jaffe, Eric (July 1, 2006). "Sight for 'Saur Eyes: T. rex vision was among nature's best". Science News 170 (1): 3-4.
  13. Erickson, Gregory M.; Makovicky, Peter J.; Currie, Philip J.; Norell, Mark A.; Yerby, Scott A.; Brochu, Christopher A. (2004). "Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs". Nature 430 (7001): 772-775.
  14. Bryner, Jenna. "T. Rex Was A True Killer". LiveScience.com. N.p., 2008. Web. 23 Jan. 2016.
  15. Switek, Brian (October 2012). "The Tyrannosaurus Rex's Dangerous and Deadly Bite". Smithsonian.com.
  16. Bates, K.T & Falkingham P.L. (2012). Estimating maximum bite performance in Tyrannosaurus rex using multi-body dynamics. Biological Letters.
  17. Crispian Scully, (2002) Oxford Handbook of Applied Dental Sciences, Oxford University Press -ISBN 978-0-19-851096-3 P156
  18. Meers, Mason B. (August 2003). "Maximum bite force and prey size ofTyrannosaurus rex and their relationships to the inference of feeding behavior".Historical Biology: A Journal of Paleobiology 16 (1): 1-12.
  19. Amos, Jonathan (2003-07-31). "Science/Nature | T. rex goes on trial". BBC News. Retrieved 2015-12-23.