Page 33 - DINOSOUR ATLAS

tenontosaurus
A large animal with a long
tail, Tenontosaurus resembled
Iguanodon, which it may be related
to. It was a plant-eater that moved
on its back legs, but dropped to
all-fours when feeding.

Cedar Mountain 5 4 ! ( #

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About 110 million yeArs Ago, the states of Utah and Colorado were a forested 'REEN 2IVER !RCHES ,
floodplain dotted with pools and crossed by rivers. There were wet and dry (SFFO .ATIONAL 0ARK
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seasons, and after heavy rain the rivers would swell and burst their banks, -OAB .PVOU 1FBMF 2
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#ANYONLANDS
spilling water filled with muddy sediment across low-lying ground. .ATIONAL 0ARK #EDAR N !
Many species of dinosaur lived on the plain, including the carnivore .PVOU &MMFO $PMPSBEP -OUNTAIN $
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Utahraptor, and Gastonia, an armored dinosaur. Fish, turtles, N /
and crocodiles swam in the rivers and pools. The area’s ancient -BLF 1PXFMM
life forms were first recognized in the 1940s, since when the
Cedar Mountain Formation has become a major location for u site location
the study of Early Cretaceous dinosaurs in North America.
The Early Cretaceous rocks of the
Cedar Mountain Formation occur in the
southwestern US, in eastern Utah and
d gastonia
parts of Colorado. It includes the sandstones
An early member of the ankylosaur (armored dinosaur) family, of Arches National Park.
Gastonia’s neck, back, and tail were covered in wide, flat, bony spines.
It was a herbivore that probably grazed on ferns and other ground
plants. Many specimens have been found in the rocks of the
Cedar Mountain Formation, suggesting it was one of the Longest spines were at
area’s common dinosaurs. the shoulders, reaching
lengths of 12 in (30 cm)
in an adult

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