FossilsFossils

Links to the pastLinks to the past

What is a fossil?What is a fossil?

• A fossil is any evidence that life once existed. This includes:– Footprints– Marks and Impressions– Parts of an organism– Anything else that suggests that life once

lived in a particular area.

Imprint FossilsImprint Fossils

• Imprint fossils are formed when an organism leaves footprints or other marks in the mud or sand.

• The mud or sand hardens into sedimentary rock, preserving the print.

Preserving is a fancy word that means to keep something from changing.

Here are some examples of imprint fossilsHere are some examples of imprint fossils

Dinosaur footprint Dinosaur tracks

Some fossils are parts of the bodySome fossils are parts of the body

• You’ve probably seen dinosaur bones in the museum.

• Well, guess what? They aren't really bones. There fossils.

• There is a difference.

• In order to understand this, we need to see how fossils of this kind are formed.

This is Danny the Dinosaur. He lived happily here in Utah about 144 million years ago. He likes palm trees.

One day, a nearby volcano erupts! It spews hot poisonous gases into the air. Danny and his favorite tree are overcome by the stinky fumes!

Tragically, Danny dies. (Hey, it’s a story about an extinct animal, what did you expect?)

As his body lies in the sun, his skin and muscles rot away, leaving only his teeth and bones.

One day, a mud slide covers Danny’s bones.

And, as if that weren’t enough, it happens again.

Over time, the mud hardens into sedimentary rock.

After millions of years, even Danny’s bones and teeth have rotted away. The only thing that’s left of poor Danny is a hole in the rock.

Over the years, rain falls on the sedimentary rock. The rain seeps through the pores in the rock, and it carries minerals down into the Danny-shaped hole.

After some time, Danny’s hole is completely filled with mineral deposits. These deposits harden into rock.

Now, 144 million years after Danny died, a Paleontologist named Steve comes to dig up some fossils for the museum. He knows that fossils are likely to be found in sedimentary rock. He starts digging.

After many hours of very hard work, Steve, the paleontologist, uncovers the amazing fossils left behind by Danny. He carefully digs them out one at a time with his trusty hammer and paintbrush.

Now, Danny is happily on display at the University of Utah Museum of Natural History. People come to take pictures of him, but sometimes, he still misses his palm tree.

The end

• Now we know how fossils are formed. How can we know where to locate them?

• Look for sedimentary rocks such as shale and limestone. They often hide fossils.

• Look carefully. Some fossils are very small.

Here are some pictures of fossils that can be found near us.

Looking at these, What inferences can be made about our valley a long time ago?

That concludes our exploration of fossils.That concludes our exploration of fossils.

Teachers: If you want a fun activity, do a Google images search for “Fossils”