Precambrian
The years of the Precambrian Period
What is from Earth's formation 4.6 billion years ago until about 541 million years ago?
The years the Cambrian Period took place
What was from 541 million years ago to about 485 million years ago?
The years of the Silurian Period
What are 444 million years ago to around 419 million years ago
The years of the Carboniferous
What is 359 million years ago to 299 million years ago?
The years of the Triassic Period
What is 252 million years ago to 201 million years ago?
The first life on our planet
What are single-celled organisms called prokaryotes?
A group of hard-bodied arthropods that emerged during the Cambrian
What are trilobites?
Some of the firsts that developed on Earth during the Silurian
What are the first primitive plants, coral reefs, and jawed fish?
The firsts on Earth during the Carboniferous Period
What are the first flying insects, the first amphibians, and the first reptiles?
Characteristic of the very first dinosaurs
What is a small size?
The first organisms to make oxygen via photosynthesis
What are cyanobacteria?
A warm and humid period on Earth when new life flourished, especially in the water.
What is the Ordovician Period?
What is the age of fish?
The reason the weather became cooler and drier and the swamps and rainforests began to decrease during the Permian
What is Pangea?
Flying reptiles that populated the Triassic world
What are pterosaurs?
What are soft-bodied creatures living in the ocean?
A fish with a bony shield and jawless mouth that thrived during the Ordovician
What is Sacabambaspis?
Stethocanthus
What is an ancestor to modern sharks that was one of the first cartilaginous fish?
Something scientists have learned from fossil footprints and trackways
What is if animals traveled alone or in groups?
More complex cells that emerged later in the Precambrian
What are eukaryotes?
A frightening sea scorpion that could grow to a length of 4 feet
What is Megalograptus?
The first animals to test out full-time life on land
What are centipedes and spiderlike creatures?
How the Permian Period ended
What is likely the worst mass extinction event in history?
The climate and landscape of Earth during the Triassic
What is very warm with vast deserts and cooler, wetter coastal regions?