Key Earth Science Links
Jurassic/Cretaceous—The largest land animals of all time
Sauropods were long-necked dinosaurs that were the largest (heaviest, tallest, and longest) land animals of all time. There is, however, some debate about which sauropod dinosaur (which genera and species) were the tallest, heaviest, and longest. Some of these dinosaurs are known from near-complete skeletons, while others are known only from fragmentary remains. Scientists compare fragmentary remains to skeletal parts in the known complete skeletons to estimate how proportionally tall, long, or heavy a whole dinosaur would have been if it were known from a complete skeleton. You can use the following web sites to discover more about these giant creatures and the debates concerning which were the tallest, heaviest, and longest!
What were the longest/heaviest dinosaurs? Mike Taylor. Dinosaur FAQ. Good synopsis of the different possibilities based on near-complete skeletons and fragmentary skeletons. Also links to how dinosaur weight is estimated.
Size of the dinosaurs. Enchanted Learning. Non-technical summary of longest, tallest, and smallest dinosaurs aimed at school children.
Earthshakers-the largest dinosaurs to walk the earth. UK dinosaurs by Gavinrymill.com. Short descriptions and drawings of candidates for the longest and tallest dinosaurs.
Argentinosaurus. Wikipedia. This dinosaur is known from fragmentary remains. The website provides a brief description of this giant Diplodocus-like sauropod and a chart that compares this dinosaur to the projected sizes of other sauropod dinosaurs.
Sauroposeidon. BBC News. News article about the discovery of fragmentary remains of this giant Brachiosaurus-like sauropod with a chart that compares this dinosaur to Brachiosaurus.
Sauroposeidon-Oklahoma’s native giant. Wedel, M.J., and Cifeli, R.L. Technical paper and description of the fragmentary remains of this giant Brachiosaurus-like sauropod. Includes information on how size and lifestyle of this giant are interpreted.
Supersaurus and Ultrasauros. Wikipedia. Short summary of these two giant sauropods, named for fragmentary fossil remains. Ultrasaurus was subsequently determined to be a junior synonym of Supersaurus, rather than two different giant sauropods.
Sauropods. Scott Hartmann-Skeletal Drawing. Drawings of reconstructed Supersaurus, Seismosaurus, Diplodocus and other sauropods, showing the bones known for each, with some size comparisons.
Seismosaurus cut down to size. ScienceDaily. News article about revision in the over-exxagerated size estimates of the Diplodocus-like sauropod, Seismosaurus.
Dinosaur “heaven” reveals wonders. BBC News. News article about the discovery of the fragmentary remains of the giant Cretaceous sauropod Paralititan in Egypt.
Brachiosaurus. Wikipedia. Good summary of Brachiosaurus. The skeleton in the Humbolt museum, Berlin, is the tallest complete dinosaur skeleton in the world.
Brachiosaurus display. Research Casting International. Photo of the Berlin Brachiosaurus, the tallest complete dinosaur skeleton in the world.
Diplodocus. Wikipedia. Summary of the sauropod dinosaur Diplodocus. A near-complete specimen of this dinosaur is the longest dinosaur skeleton in the world.
Diplodocus. Carnegie Museum of Natural History. Brief summary of the sauropod dinosaur Diplodocus, and the history of discovery of the near-complete specimen at the museum, which remains the longest complete dinosaur skeleton in the world.
Dinosaur weight/mass
Dinosaur weights are generally estimated by calculating the volume of a dinosaur that has been based on its skeletal structure and then using an average weight of bone and tissue per unit volume to calculate mass. The accuracy of the models obviously can have considerable bearing on the results, as can assumptions about the average weight of tissues in reptiles, birds, and mammals; but this method provides a general idea of how heavy extinct animals were.
Estimating the Live Mass of Dinosaurs. Tim Culp and Harry Wolf. Woodrow Wilson Biology Institute. High School activity that shows students how to measure the volume of toy dinosaurs in water, scale their toy to the actual length of the dinosaur, and then calculate the mass of the actual dinosaur from the volumes they estimated.
Why do dinosaur weight estimates vary so much? Mike Taylor. Brief explanation of methods for determining dinosaur weights and the reasons for variations in the weights interepreted.
Dinosaur Size. Wikipedia. Online encyclopedia reference of the longest, most massive, and smallest dinosaurs in each of several dinosaur groups. Check most massive sauropods to discover the heaviest dinosaurs (and land animals) of all time. A large list of heavy sauropods provides estimates of weights for different genera and the technical references for the weights.
Mike Taylor provides the following technical references for estimating dinosaur weights from the dinosaur mailing list. Some may be available online. Colbert (1962) developed the original calculations that have been used or modified by many scientists.
- Alexander, R. McNeill. 1985. Mechanics of posture and gait of some large dinosaurs: Zoological Journal of the Linnean Society 83: 1-25.
- Alexander, R. McNeill. 1989. Dynamics of Dinosaurs and Other Extinct Giants. Columbia University Press, New York. 167 pp.
- Colbert, Edwin H. 1962. The weights of dinosaurs. American Museum Novitates, 2076, pp. 1-16.
- Henderson, Donald M. 1999. Estimating the masses and centers of mass of extinct animals by 3-D mathematical slicing.
- Mazzetta, Gerardo V., Per Christiansen and Richard A. Farina. 2004. Giants and Bizarres: Body Size of Some Southern South American Cretaceous Dinosaurs. Historical Biology, 2004, 1-13.
- Paul, G. S. 1988. The brachiosaur giants of the Morrison and Tendaguru with a description of a new subgenus, Giraffatitan, and a comparison of the world's largest dinosaurs. Hunteria 2 (3): 1-14.
- Paul, G. S. 1997. Dinosaur models: the good, the bad, and using them to estimate the mass of dinosaurs. Pp. 129-154 in D. L. Wolberg, E. Stump, and G. D. Rosenberg, eds. DinoFest International: Proceedings of a Symposium Sponsored by Arizona State University. Academy of Natural Sciences, Philadelphia.