- Astrodon
Taxobox|
status = fossil
name = "Astrodon"
regnum =Animal ia
phylum = Chordata
classis =Sauropsid a
ordo =Saurischia
subordo =Sauropodomorpha
infraordo =Sauropoda
familia =Titanosauriformes
genus = "Astrodon"
species = "A. johnstoni"
binomial = "Astrodon johnstoni"
binomial_authority = Leidy, 1865"Astrodon" was a
genus of large herbivorousdinosaur , related to "Brachiosaurus ", that lived in what is now the easternUnited States during theEarly Cretaceous period.Palynomorph s have been used to date the Arundel to theAptian , which is 121-112 million years ago. Adults are estimated to have been more than 30 feet (9.1 m) high and 50 (15.2 m) to 60 (18.3 m) feet long.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 aspecific epithet , soJoseph Leidy is credited with naming "Astrodon johnstoni" (thetype 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 1921Charles W. Gilmore argued that the name "Astrodon" 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. "Astrodon" is sometimes considered a synonym of "Pleurocoelus", but the jury is still out on which name is correct. Carpenter and Tidwell therefore consider the two species named by Marsh, "nanus" and "altus", as different growth stages of "Astrodon johnsoni".cite book|author=Carpenter, Kenneth and Tidwell, Virginia|year=2005|chapter=Reassessment of the Early Cretaceous Sauropod "Astrodon johnsoni" Leidy 1865 (Titanosauriformes)|editor=Carpenter, Kenneth and Tidswell, Virginia (ed.)|title=Thunder Lizards: The Sauropodomorph Dinosaurs|pages=38–77|publisher= Indiana University Press|id=ISBN 978-0-253-34542-4]In 1998, "Astrodon johnstoni" was named the state dinosaur of
Maryland .References
External links
* [http://www.dinodata.org/index.php?option=com_content&task=view&id=5918&Itemid=67 "Astrodon"] at DinoData
* [http://www.mdarchives.state.md.us/msa/mdmanual/01glance/html/symbols/dino.html Maryland State Archives]
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