Lesson2

What is taphonomy?

The study of all natural processes that involve an organism after it dies, including decay, scavenging, fossilization, and erosion.

What is the phenomenon called when a carcass swells with putrid gases and can float?

Bloat-and-float.

Why is fossilization more common in wet environments?

Because bone burial can occur when water washes sand or mud over a carcass.

What type of sedimentary deposits are associated with ancient river and stream environments?

Fluvial deposits.

What preservation style occurs when the empty internal spaces of a bone are filled with minerals?

Permineralization.

What is plastic deformation in the context of fossils?

The change in shape of a buried fossil due to pressure, which does not return to its original shape after the pressure is removed.

Name a special type of sedimentary rock that indicates a former swampy environment.

Coal.

What types of rocks predominantly preserve dinosaur fossils?

Sedimentary rocks.

How are fossils typically transported from a dig site to a laboratory?

Wrapped in protective material and covered with burlap soaked in plaster to form a strong jacket.

What are the signs that indicate how far bones have been transported by water?

The amount of abrasion on the bones.

What indicates that long bones in a bonebed were transported by water?

Their alignment in the same direction.

What feature of sedimentary rocks indicates a former lake bottom environment?

Mudstone and shale.

How are bones generally excavated once they are mapped?

Overburden removal using large tools, followed by careful excavation with hand picks and brushes.

What are the two main types of fossil preservation for dinosaur bones?

Permineralization and replacement.

What terrestrial environments are generally poor for fossil preservation?

Ancient deserts represented by aeolian deposits.

What could cause a dinosaur to be preserved in a crouching position?

Sand dunes collapsing onto the animal when saturated, such as during heavy rain.

What is the role of sedimentology in paleontology?

It is the science of how sedimentary rocks form, which can provide clues about fossil habitats.

Why is it important to map the location of bones in a excavation?

To assist in reconstructing skeletons and understanding taphonomic processes.

What happens to fossils that are exposed for a long time at the surface?

They may become badly weathered due to environmental effects like rain and freeze-thaw cycles.