name = "Haplocanthosaurus"
image_width = 250px
image_caption = "Haplocanthosaurus priscus" sacrum.
phylum = Chordata
classis = Sauropsida
familia = Haplocanthosauridae
familia_authority = Bonaparte, 1999
genus = "Haplocanthosaurus"
genus_authority = Hatcher, 1903
* "H. priscus" (Hatcher, 1903) (type)
* "H. delfsi" Hatcher, 1903
"Haplocanthosaurus" (meaning "simple spined lizard") is a
genusof sauropod dinosaur. Two species, "H. delfsi" and "H. priscus", are known from incomplete fossilskeletons. It lived during the late Jurassicperiod ( Kimmeridgian- Tithonianstages), 144 to 156 million years ago. It was first discovered by a young college student named Edwin Delfs in Colorado. "Haplocanthosaurus" specimens have been found in the very lowest layer of the Morrison Formation, along with " Hesperosaurus", " Eobrontosaurus", and "Allosaurus jimmadensi".Foster, J. (2007). "Jurassic West: The Dinosaurs of the Morrison Formation and Their World". Indiana University Press. 389pp.]
"Haplocanthosaurus priscus" was originally named "Haplocanthus priscus" by
John Bell Hatcherin 1903. Soon after his original description, Hatcher came to believe the name "Haplocanthus" had already been used for a genus of acanthodian fish ("Haplacanthus", named by Louis Agassizin 1845), and was thus preoccupied. Hatcher re-classified his sauropod later in 1903, giving it the new name "Haplocanthosaurus".Hatcher, J.B. (1903a). "A new name for the dinosaur "Haplocanthus" Hatcher." "Proceedings of the Biological Society of Washington", 16: 100.] However, the name was not technically preoccupied at all, since there was a variation in spelling: the fish was named "Haplacanthus", not "Haplocanthus". While "Haplocanthus" technically remained the valid name for this dinosaur, Hatcher's mistake was not noticed until many years after the name "Haplocanthosaurus" had become fixed in scientific literature. When the mistake was finally discovered, a petition was sent to the ICZN(the body which governs scientific names in zoology), which officially discarded the name "Halplocanthus" and declared "Haplocanthosaurus" the official name (ICZN Opinion #1633).
Originally described as a "cetiosaurid",
José Bonapartedecided in 1999 that "Haplocanthosaurus" differed enough from other sauropods to warrant its own family, the Haplocanthosauridae.Bonaparte, J. F. (1999). "An armoured sauropod from the Aptian of northern Patagonia, Argentina." In Tomida, Y., Rich, T. H. & Vickers-Rich, P. (eds.), 1999." Proceedings of the Second Gondwanan Dinosaur Symposium", National Science Museum Monographs #15, Tokyo: 1-12.] Phylogeneticstudies have failed to clarify the exact relationships of "Haplocanthosaurus" with any certainty. Studies have variously found it to be more primitive than the neosauropods,Upchurch, P. (1999). "The phylogenetic relationships of the Nemegtosauridae (Saurischia, Sauropoda)." "Journal of Vertebrate Paleontology", 19: 106–125.] a primitive macronarian (related to the ancestor of more advanced forms such as " Camarasaurus" and the brachiosaurids),Wilson, J.A., and Sereno, P.C. (1998). "Early evolution and higherlevel phylogeny of sauropod dinosaurs." "Society of Vertebrate Paleontology Memoir", 5: 1–68.] or a very primitive diplodocoid, more closely related to " Diplodocus" than to titanosaurs, but more primitive than rebachisaurids.Wilson, J.A. (2002). "Sauropod dinosaur phylogeny: critique and cladistic analysis." "Zoological Journal of the Linnean Society", 136: 217–276.]
Darren Naishand Mike Taylor reviewed the various proposed positions of "Haplocanthosaurus" in their study of diplodocoid phylogeny.Taylor, M.P. and Naish, D. (2005). "The phylogenetic taxonomy of Diplodocoidea (Dinosauria: Sauropoda)." "PaleoBios", 25(2): 1–7.] These positions are represented in the cladogrambelow.
"Haplocanthosaurus" was one of the smallest sauropods of the Morrison. While most Morrison sauropods could reach lengths of over 20 meters (or over 70 feet), "Haplocanthosaurus" wasn't nearly as large, and reached a total length of 14 meters (46 feet) and an estimated weight of 14.5 metric tons.McIntosh, J.S., Brett-Surman, M.K., and Farlow, J.O. (1997). "Sauropods." Pp. 264 –290 in Farlow, J.O. and Brett-Surman, M.K. (eds.), "The Complete Dinosaur". Indianapolis: Indiana University Press.]
There are four known specimens of "Haplocanthosaurus", one of "H. delfsi", and three of "H. priscus". Of these, the type of "H. delfsi" is the only adult, and the only one complete enough to mount. The mounted specimen of "H. delfsi" now stands in the
Cleveland Museum of Natural History, albeit with a dragging tail posture and a completely speculative replica skull, as the actual skull was not recovered.
-The Cleveland Museum of Natural History
Wikimedia Foundation. 2010.
Look at other dictionaries:
Haplocanthosaurus — delfsi Zeitraum Oberer Jura 155,7 bis 145,5 Mio. Jahre Fundorte Nordamerika (Morrison Formation) … Deutsch Wikipedia
Haplocanthosaurus — Haplocanthosaurus Rango temporal: Jurásico superior … Wikipedia Español
Haplocanthosauridae — Haplocanthosaurus Rango temporal: Jurásico Tardío … Wikipedia Español
Dinosaurs of the Morrison Formation — Further information: Morrison Formation The Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has been the most fertile source of dinosaur fossils in North America. It … Wikipedia
Sauropoda — Taxobox name = Sauropods fossil range = Late Triassic Late Cretaceous image width = 250px image caption = Alamosaurus , a titanosaur. regnum = Animalia phylum = Chordata classis = Sauropsida superordo = Dinosauria ordo = Saurischia subordo =… … Wikipedia
Sauropoda — Sauropoden Lebendrekonstruktion von Argentinosaurus, einem der größten Sauropoden, aus der Kreide von Südamerika Zeitraum Obertrias bis Oberkreide … Deutsch Wikipedia
Sauropode — Sauropoden Lebendrekonstruktion von Argentinosaurus, einem der größten Sauropoden, aus der Kreide von Südamerika Zeitraum Obertrias bis Oberkreide … Deutsch Wikipedia
Sauropoda — Sauropodes … Wikipédia en Français
Sauropode — Sauropoda Sauropodes … Wikipédia en Français
Sauropodes — Sauropoda Sauropodes … Wikipédia en Français