Fossils 101
Remains, imprints, or traces of prehistoric organisms are known as these.
What are fossils?
Insects can be preserved in this golden substance, which is actually hardened tree resin.
What is amber?
According to this law, in an undisturbed sequence of rocks, the oldest layers are at the bottom.
What is the Law of Superposition?
The amount of time it takes for half of the radioactive parent atoms in a sample to decay.
What is a half-life?
We are currently living in this Era, often called the "Age of Mammals."
What is the Cenozoic Era?
This type of scientist blends geology and biology to study the succession of life in Earth’s history
Who is a paleontologist?
Tracks, burrows, and coprolites are examples of this type of fossil that shows how an organism lived.
What are trace fossils?
This term describes the age of a rock in comparison to other things (e.g., "older" or "younger") rather than its age in years.
What is relative age?
This element is used to date relatively young rocks and fossils because it has a short half-life of 5,730 years.
What is Carbon-14?
This "middle life" era was the age of reptiles and dinosaurs.
What is the Mesozoic Era?
To form a fossil, an organism usually needs these durable features, such as bones, shells, or teeth.
What are hard parts?
This forms when a shell buried in sediment dissolves, leaving behind an empty space in the shape of the organism.
What is a mold?
The Law of Cross-Cutting states that if a fault cuts through a rock layer, the fault is __________ than the rock.
What is younger?
When an unstable radioactive parent atom decays, it turns into this type of atom.
What is a daughter atom?
These bacteria were the first life forms, appearing about 3.5 billion years ago.
What are cyanobacteria?
Fossils are almost exclusively found in this type of rock, as others would destroy animal remains.
What is sedimentary rock?
This process occurs when mineral-rich groundwater permeates tissue, turning wood or bone into stone.
What is permineralization?
"One-hit wonders" of the fossil record, these widespread but short-lived species help date rock layers easily.
What are index fossils?
This method is used to determine the absolute age of rocks and fossils by analyzing atomic decay.
What is radiometric dating?
A mass extinction is defined as an event where at least this percentage of species die over a short period.
What is 75%?
The root word "Paleo," as in Paleontology or Paleozoic, translates to this in English.
What is "old" or "ancient"?
A thin residue left behind when pressure squeezes liquids and gases out of an organism.
What is a carbon film?
Sediments are naturally deposited in flat layers due to gravity, according to the Law of Original ____________.
What is Horizontality?
With a half-life of 4.5 billion years, this element is used to date the oldest rocks on Earth.
What is Uranium-238?
Geologists estimate the age of the Earth to be approximately this many years old.
What is 4.54 billion years?