Vocabulary
The reserve remains of an organism that lived in the past.
fossil
A radioactive isotope is commonly used to date organic material up to 50,000 years old.
Carbon-14
The earliest, longest, and "hidden" span of Earth's history covers about 88% of Earth's history.
Precambrian
Named for the Greek for "ancient life," this era covers the time from the Cambrian Explosion to the Permian extinction.
Paleozoic Era
This unit of measurement, equal to 4 inches, is used to determine a horse's height from the ground to its withers.
Hands
The age of a rock given as the number of years since the rock formed.
absolute age
The time it takes for half of a radioactive isotope to decay into stable isotopes is called this.
Half-Life
The Era, known as the "Age of Reptiles," saw the rise and fall of the dinosaurs.
Mesozoic Era
The name for the enormous supercontinent that existed approximately 335 to 175 million years ago.
Pangaea
This term describes a castrated male horse, known for being calmer than a stallion.
Gelding
The geological principle that states that in horizontal layers of sedimentary rock, each layer is older than the layer obove it and younger thn the layer below it.
law of superposition
A break in Earth's crust that is always younger than the rock that it breaks through.
fault
This current era, meaning "modern life," began 65 million years ago following the extinction of the dinosaurs.
Cenozoic Era
Approximately 4.6 billion years ago, this first eon of Earth's history saw the planet form, cool, and develop its initial crust.
Hadean Eon
This rotating shaft at the rear of a tractor transfers mechanical power directly from the engine to attached implements like balers or mowers.
Power Take-Off (PTO)
A gap in the geological record that shows where rock layer have been lost due to erosion.
uncomformity
The method measures the ratio of radioactive parent isotopes to stable daughter isotopes in a rock.
Radiometric Dating
A "sudden" or quick explosion of diverse life forms occurred at the beginning of this period.
Cambrian Period
This critical event, around 2.4 billion years ago, was caused by cyanobacteria and drastically changed Earth's atmosphere.
Great Oxidation Event
This critical, nutrient-rich "first milk" produced by a mother mammal immediately after giving birth is vital for the newborn's passive immunity.
Colostrum
The process of determining the age of an object using the half-life of one or more radioactive isotopes.
radioactive dating
This type of dating gives the exact number of years since a rock was formed, rather than a comparison.
Absolute Age
Geologists define these, the smallest, most specific unit of time, by minor changes in rock layers.
Epochs
This event, occurring around 66 million years ago, led to the extinction of the dinosaurs.
K-Pg extinction
This is the specific name of the lowest internal deck compartment located behind the trailer axles, often requiring animals to walk down a steep internal ramp to enter.
Doghouse