Week 2 Study Guide - History of Dinosaur Science, Rocks, Time, and Fossils

What was Georges Cuvier known for?

Comparative anatomy and establishing that extinction is real.

What did Richard Owen contribute to dinosaur science?

He coined the name Dinosauria and recognized dinosaurs had an upright posture.

What was the Scala Naturae?

The “Great Chain of Being,” an old idea that organisms could be arranged in a hierarchy from lower to higher/more perfect forms.

What were the Bone Wars?

A rivalry between paleontologists Edward Drinker Cope and Othniel Charles Marsh over discovering and naming fossils.

What did Roy Chapman Andrews discover?

His expeditions in Mongolia discovered the first known dinosaur eggs and nests.

What was the Dinosaur Renaissance?

A major change in dinosaur research during about 1970–1985 that portrayed dinosaurs as active, dynamic animals rather than slow, sluggish reptiles.

What did John Ostrom contribute to the Dinosaur Renaissance?

His study of Deinonychus supported the idea that dinosaurs were active and that birds descended from dinosaurs.

What is uniformitarianism?

The idea that the geological processes we observe today also operated in the past; “the present is the key to the past.”

What are the three types of rocks?

Igneous, sedimentary, and metamorphic.

How do igneous rocks form?

When molten material cools and solidifies.

How do sedimentary rocks form?

From deposited sediments that become compacted/cemented, or from chemical/biological material.

How do metamorphic rocks form?

When existing rocks are changed by heat, pressure, or chemical processes without completely melting.

What is relative dating?

Determining whether something is older or younger than something else without giving a numerical age.

What is absolute dating?

Determining a numerical age or age estimate.

How does radiometric dating work?

It uses the predictable decay of radioactive parent isotopes into daughter isotopes to determine age.

What is a half-life?

The amount of time required for 50% of a radioactive parent isotope to decay.

How old is Earth?

About 4.54 billion years old.

What is the principle of superposition?

In an undisturbed sequence of sedimentary rocks, the oldest layers are on the bottom and the youngest are on top.

What is original horizontality?

Sedimentary layers are originally deposited approximately horizontally.

What is cross-cutting?

A feature that cuts through another rock is younger than the rock it cuts.

What is faunal succession?

The principle that fossils occur in predictable sequences through the rock record and can be used to correlate rock ages.

What is a body fossil?

Preserved remains or parts of an organism, such as bones, teeth, shells, or leaves.

What is a trace fossil?

Preserved evidence of an organism’s behavior, such as footprints, burrows, nests, or coprolites.

What is original-material fossilization?

Preservation of the organism’s original material.

What is recrystallization?

When the original mineral changes into a different crystal form while remaining chemically similar.

What is replacement?

When the original fossil material is removed and replaced by another mineral.

What is permineralization?

When minerals fill the natural pores or spaces within an organism’s remains, such as bone or wood.

What is a mold?

An empty impression left after the original organism or material dissolves or decays.

What is a cast?

A copy of an organism formed when a mold becomes filled with sediment or minerals.

What is carbonization?

The preservation of a thin, carbon-rich film after an organism is compressed and much of its material is lost.

How do burial and transportation affect fossil preservation?

Fast burial and low transportation generally improve preservation because they reduce exposure to decay, scavenging, weathering, and abrasion.

What are Lagerstätten?

Fossil deposits with exceptionally abundant and/or exceptionally well-preserved fossils, sometimes including soft tissues.