Despite being fully aquatic, these ancient fish had primitive lungs.
Ancient Lungfish
A meteor took out the last of the dinosaurs in this extinction.
The Cretaceous Extinction
This inhospitable location is a treasure trove of early tetrapod fossils. Watch out for polar bears!
The Arctic
The preserved remains, impression, or trace of any once-living organism
Fossil
Missing in fish but present in many tetrapods, this joint found at the end of an appendage first appeared 400 years ago.
Wrist
They had no wrists, but this ancient "fish" had the first true fingers and toes.
Acanthostega
The largest extinction in earth's history (for now)
The Permian Extinction
The bodies of snails often dissolve before fossilization, leaving behind only this part.
Shell
A scientist who studies fossils.
Paleontologist
Generally speaking, the oldest rock is found at the _______ of a formation.
Bottom
This organism is considered to be the first true tetrapod.
Perdepes
The first in earth's history, this extinction took out 86% of all life.
The Ordovician Extinction
It's generally agreed upon that all life began here.
The ocean or water.
Used to describe any vertebrate with four legs, ancient or modern.
Tetrapod
One, two, many
Living over 380 million years ago, these fish are some of the oldest organisms to follow the one bone, two bone, many bone pattern.
Eusthenopteron
Global warming caused by the continents shifting caused this often overlooked ancient extinction.
The Triassic Extinction
An excavation in downtown LA? This paleontological site is world renowned for its preservation of fossils and even complete, intact bones.
La Brea Tar Pits
Not just one leaf imprint or one bone in a rock, but this word is used to refer to every fossil that has ever been discovered.
The Fossil Record
This principal allows us to to conclude that organisms found on the same layer likely lived around the same time.
Superposition
Considered one of the most important transitionary species, the discovery of its fossil confirmed much of what was only a theory up to that point.
Tiktaalik
Bye bye, fishies. This extinction ended the so called "Age of the Fish."
The Devonian Extinction
The oldest fossil we studied, these little fellas skittered across the ocean floor over 525 million years ago.
Trilobite
The word we use the describe the diversity of life forms on earth.
Biodiversity
Modern tetrapods all share this characteristic at the end of their limbs, even when not immediately obvious.