Page 30 - DINOSOUR ATLAS

north america
Petrified Forest GU N 1BJOUFE %FTFSU
1JMPU 3PDL

.AVAJO
#HINDE 0OINT
In northeastern arIzona there is a remarkable site from the Late Triassic. 1VFSDP 3JWFS
About 220 million years ago, a great forest of conifer trees grew somewhere
in this area. In times of flood many were uprooted, carried along by the (OLBROOK
water, and piled up in heaps on the land, where they were slowly
fossilized. Today, these ancient tree trunks lie scattered across 0ETRIFIED &OREST
.ATIONAL 0ARK
the landscape, in an area known as the Petrified Forest National
Park. There are also fossils of the world’s first dinosaurs, such
as Chindesaurus, together with amphibians and large-tusked
plant-eaters called dicynodonts. u site location
Petrified Forest National Park was established in
, forest of giants 1962. As early as 1899, the United States Geological
Survey had sought to protect the area. It covers
The fossilized trees of the Petrified Forest National Park 342 sq miles (885 sq km).
mainly belong to the Araucariaceae family. They were conifers, many
of which were similar to today’s monkey puzzle trees. From their fossilized
trunks it’s clear that when fully grown the trees reached heights of around
165 ft (50 m), with trunks more than 2 ft (60 cm) across. Down on the
ground, where light levels were low,
grew ferns and horsetails. , chindesaurus
This is one of
North America’s
eRosion removed the oldest dinosaurs.
step 1 overlying rock, exposing A small-sized meat-
the fossilized tree eater, Chindesaurus had long
Fully gRown hind legs, indicating that it
coniFeR could
be 200 ft (60 m) was probably a fast mover.
tall with deep roots It is known from a partial
step 2 single specimen, collected at Chinde Point
in Petrified Forest National Park.
FloodwateR
washed the soil from
the roots, and the step 3
tree floated away tRee turned step 4 lungfish fossil .
to stone under layers Out of the area’s sandstone rocks
of gravelly sand, rich come the fossils of lungfish, revealing
in volcanic ash
d today’s landscape that long ago the landscape had rivers
and lakes where these animals lived.
The fossilized trees lie where ancient floodwaters Ancient lungfish, like those of today,
dropped them, more than 200 million years ago. were fish that could breathe air, with
Since then, wind, water, and ice have weathered away limbs more like flippers than fins.
the rock that entombed them, leaving them visible on
the land surface. As the minerals that transformed Red of the fossilized
their bark and wood into stone are brightly colored, trees is from the
these petrified logs are sometimes known mineral hematite,
a form of iron oxide
as “rainbow wood.”

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