View source for Edmontosaurus

{{italictitle}}
{{taxobox
| name = ''Edmontosaurus''
| fossil_range = [[Upper Cretaceous]] 73–65.5 mya
| image = Hadrosauridae - Edmontosaurus annectens.JPG
| image_width = 250px
| image_caption = Mounted skeleton of ''E. regalis''
| regnum = [[Animalia]]
| classis = [[Sauropsida]]
| superordo = [[Dinosauria]]
| ordo = [[Ornithischia]]
| subordo = [[Ornithopoda]]
| familia = [[Hadrosauridae]]
| genus = '''''Edmontosaurus'''''
| species = '''''E. regalis''''' <br> '''''T. regalis'''''
}}

'''Edmontosaurus''' is a basal [[duck-billed dinosaur]] from the latest [[Cretaceous]] stage. It had short arms, a long, pointed tail, three-toed, hoofed feet, and mitten-like hands. Its head was flat and sloping with a wide, toothless beak, cheek pouches, and hundreds of closely-packed cheek teeth that ground up its food. It is the same animal as'' Anatotitan''. There are two [[species]], and the animal has been called by several other names in the past.''

''Edmontosaurus'' was named from a fossil found in the  Horseshoe Canyon Formation,<ref>Formerly called the lower Edmonton Formation.</ref> in [[Alberta]], Canada. Many'' Edmontosaurus ''fossils have been found, in Alberta, and [[Alaska]], [[Wyoming]], [[Montana]] and [[New Jersey]] in the [[United States|USA]]. Two mummified'' Edmontosaurus ''fossils were found in Wyoming.''

The distribution of its fossils suggests that it preferred [[coast]]s and coastal [[plains]]. It could move on two legs and on four. Because it is known from several bone beds, ''Edmontosaurus'' is thought to have lived in groups. It may have been [[migratory]].

== Skeleton ==
[[File:Edmontosaurus pelvis left.jpg|thumb|Hip bones of ''E. annectens'', an [[ornithischia]]n dinosaur]]

Most of the back and tail was lined by bony [[tendon]]s arranged in a [[lattice]] along the [[neural spines]] of the vertebrae.<ref>Neural spine =  bit that sticks up</ref>  This made the back and part of the tail "ramrod" straight.<ref name=JHO64>{{cite journal |doi=10.2475/ajs.262.8.975 |last=Ostrom |first=John H. |year=1964 |authorlink=John Ostrom |title=A reconsideration of the paleoecology of the hadrosaurian dinosaurs |journal=American Journal of Science |volume=262 |pages=975–997 |issue=8}}</ref><ref name=PMG70>{{cite journal |last=Galton |first=Peter M. |year=1970 |title=The posture of hadrosaurian dinosaurs |url=https://archive.org/details/sim_journal-of-paleontology_1970-05_44_3/page/464 |journal=Journal of Paleontology |volume=44 |issue=3 |pages=464–473}}</ref> The ossified tendons strengthened the vertebral column against [[gravitation]]al stress. It was a large animal with a horizontal vertebral column otherwise supported mostly by the hind legs and hips.<ref name=JHO64/>

== Feeding ==
As a hadrosaurid, ''Edmontosaurus'' was a large terrestrial [[herbivory|herbivore]]. Its teeth were continually replaced and packed into dental batteries that contained hundreds of teeth, only a relative handful of which were in use at any time.<ref name=HWF04>Horner, John R; Weishampel, David B. & Forster, Catherine A 2004. Hadrosauridae. In Weishampel, David B; Dodson, Peter and Osmólska, Halszka (eds) ''The Dinosauria''. 2nd ed, Berkeley: University of California Press, pp. 438–463. {{ISBN|0-520-24209-2}}</ref>  It used its broad beak to cut loose food, perhaps by cropping,<ref name=HWF04/> or by closing the jaws in a clamshell-like manner over twigs and branches and then stripping off the more nutritious leaves and shoots.<ref name=JHO64/> ''Edmontosaurus'' and most other ornithischians probably had cheek-like structures, muscular or non-muscular. The function of the cheeks was to keep food in the mouth.<ref name=PMG73>{{cite journal |last=Galton |first=Peter M.|year=1973 |title=The cheeks of ornithischian dinosaurs |journal=Lethaia |volume=6 |pages=67–89 |doi=10.1111/j.1502-3931.1973.tb00873.x}}</ref><ref name=FS04>Fastovsky, D.E., and Smith, J.B. (2004). "Dinosaur paleoecology." ''The Dinosauria''. pp. 614–626.</ref>  The animal's feeding range would have been from ground level to about {{convert|4|m|ft}} above.<ref name=HWF04/>

[[File:Edmontosaurus skulls.png|thumb|250px|''Edmontosaurus'' skulls: a collection of almost all the known specimens]]

== References ==
{{reflist}}

[[Category:Hadrosauridae]]