Astrodon
| Astrodon Temporal range: Early Cretaceous, 112 Ma |
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Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Superorder: | Dinosauria |
| Order: | Saurischia |
| Suborder: | †Sauropodomorpha |
| Infraorder: | †Sauropoda |
| Node: | †Titanosauriformes |
| Family: | †Pleurocoelidae Marsh, 1888 |
| Genus: | †Astrodon Johnston, 1859 |
| Species: | †A. johnstoni |
| Binomial name | |
| Astrodon johnstoni Leidy, 1865 |
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Astrodon (astro: star, don: tooth) was a genus of large herbivorous sauropod dinosaur, related to Brachiosaurus, that lived in what is now the eastern United States during the Early Cretaceous period. Its fossils have been found in the Arundel Formation, which has been dated through palynomorphs to the Aptian-Albian boundary, about 112 million years ago.[1] Adults are estimated to have been more than 9 m (30 ft) high and 15 to 18 m (50 to 60 ft) long.
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[edit] Discovery and species
Two teeth were found in the Arundel Formation near Bladensburg, Maryland and named Astrodon in 1859 by Christopher Johnston. However, Johnston did not attach a specific epithet, so Joseph Leidy is credited with naming Astrodon johnstoni (the type species) in 1865. If Johnston had attached a scientific epithet, it would have been the second dinosaur identified in the United States.
In 1888, O.C. Marsh named some bones from the Arundel found near Muirkirk, Maryland Pleurocoelus nanus and P. altus. However, in 1921 Charles W. Gilmore argued that they both represent the same species as Astrodon johnsoni and that the name Astrodon therefore had priority, a position that Carpenter and Tidwell (2005) accepted in the first in-depth description of this dinosaur. Interestingly, the majority of the bones of Astrodon are of juveniles, and Carpenter and Tidwell considered the two species named by Marsh, P. nanus and P. altus, as different growth stages of Astrodon johnsoni.[1]
[edit] Cultural references
In 1998, Astrodon johnstoni was named the state dinosaur of Maryland. Astrodon also appears in the novel Raptor Red by Robert T. Bakker, as prey of Utahraptor.
[edit] References
- ^ a b Carpenter, Kenneth and Tidwell, Virginia (2005). "Reassessment of the Early Cretaceous Sauropod Astrodon johnsoni Leidy 1865 (Titanosauriformes)". In Carpenter, Kenneth and Tidswell, Virginia (ed.). Thunder Lizards: The Sauropodomorph Dinosaurs. Indiana University Press. pp. 38–77. ISBN 978-0-253-34542-4.
- Johnston, C., 1859, "Note on odontography," Amer. Journal Dental Sci. 9:337-343.
- Kranz, P.M. 1996, "Notes on the Sedimentary Iron Ores of Maryland and their Dinosaurian Fauna", in Maryland Geological Survey Special Publication No. 3, pp. 87-115.
- Leidy, J 1865, Memoir on the extinct reptiles of the Cretaceous formations of the United States. Smithson. Contrib. Knowl. XIV: atr. VI: 1-135.
- Lucas, F.A. 1904, "Paleontological notes," Science (n.s.) XIX (480): 436-437.
- Lull, R.S. 1911, "The Reptillian Fauna of the Arundel Formation" and "Systematic Paleontology of the Lower Cretaceous Deposits of Maryland -Dinosauria", Lower Cretaceous : Maryland Geological Survey Systematic Reports, pp. 173-178, 183-211.
- Marsh, O.C. 1888, "Notice of a New Genus of Sauropoda and Other New Dinosaurs from the Potomac Group," American Journal of Science, 3rd Series, Vol. XXXV, pp. 89-94.
[edit] External links
- Astrodon at DinoData
- Maryland State Archives
