Earth’s Landscapes

Before Video

• A fossil is evidence of past life on Earth.

• Most landscapes have changed over time. Looking at rock layers and the fossils they contain can provide evidence and clues about what it was like in the past.

• Fossils from marine life found in what is now land provides evidence that the landscape has changed over time and the land was once under the sea.

• The Earth changes over time. Some changes happen quickly, like earthquakes and volcanoes. Other changes are slow — like erosion and plate tectonics. We can see evidence of these changes in rock layers that help us understand the past.

After Video

• Fossils from whales, sharks, dolphins, and turtles are found there along with silt, which is sediment found at the bottom of the ocean.

• Although the layer of rock that contains the fossils found at Sharktooth Hill is very old, it is exposed at the Earth’s surface in some areas of the dig site so fossils can be found right on the ground. Older rocks above this fossil layer eroded over time due to water and/or wind.

• No. Scientist have not found any volcanic ash in the rock layer. They also ruled out that all the animals were eaten by sharks because very few shark bites have been found on other animals’ bones. There is no evidence to support these theories.

• The silt the bones are buried in is thought to have come from a river depositing fine sand and clay on the bottom of the ocean. Animals who died naturally in that area would have been buried and fossilized. Scientists think that the river may have stopped flowing for some time (due to a change in the climate), which meant sediment was not being deposited and animal skeletons collected on the sea floor. When the climate shifted and the river started flowing again, sediment then buried all the collected skeletons, forming the bone bed.

• The rock layers above the bone bed are younger than the bone bed. The rock layers below the bone bed are older than the bone bed.

• To know about the environment before the time the bone bed formed, you would need to dig deeper than the bone bed. Layers below it would be older.

• Scientists think that the bones were jumbled together by ocean currents. They know all the bones are about the same age due to radiocarbon dating.

• Fossils from sea creatures found in what is now the plains of the Midwest provide evidence that this area was once covered by the sea.

A fossil is evidence of past life on Earth.

A place in California located 100 miles away from the Pacific Ocean. Millions of years ago this region was under the ocean. Today it is on dry land and we find fossils of marine life like whales, sharks, dolphins and turtles in a thin layer 30 feet below the surface.

The branch of science that studies fossils of animals and plants.

Fine sand, clay, or other material carried by moving water and deposited at the bottom of a body of water like the ocean.

Sedimentary rocks are made when sand and mud gets laid down in layers. Over time, these layers are squashed under more and more layers. Eventually, the layers turn into rock.

A layer in the earth containing large quantities of fossilized animal remains.

A layer of rock often formed one on top of the other. We can learn about what the earth’s surface looked like a long time ago by studying the properties of the layers and the different kinds of fossils found in these rock layers.

A method for determining the age of an object that is thousands of years old such as a fossil. It uses the element carbon to do this. Your pencil tip is out made of carbon.

A landscape describes all the visible features of the earth’s surface. We can learn about Earth’s landscape in the past by studying rock layers and the fossils found in them.

A five-thousand-foot-deep canyon located in Arizona, a state in the USA. It was carved by the Colorado River over millions of years and is one of the best examples of weathering and erosion.

After pieces of the earth are broken down through weathering, those pieces are moved through Erosion. It’s the process of moving things from one place to another.