Please enable JavaScript.
Coggle requires JavaScript to display documents.
Vertebrate History in Rocks (Pattern of Vertebrate Evolution (Jawless…
Vertebrate History in Rocks
What are Fossils?
“A fossil is the hardened remains or other evidence of a living thing that existed a long time ago.”
Bones, shells, and skeletons are parts of living things and so are fossils.
During this chemical process the organisms Muscles are replaced with hard minerals.
“Fossils are found most frequently in sedimentary rock.”
Sediments make up sedimentary rock.
Mud, sand, or silt particles make up sediments.
Interpretation of Fossils
“By studying fossils, paleontologist can infer animals changed over time.”
Paleontologist can approximate a fossil’s age.
A Fossils Age
One method that a paleontologist can approximate the fossils age is the sediments form.
When a fossil is in the higher layers of the earth it is younger.
Fossils can be rotated due to earthquakes.
Some fossils contain radioactive chemical elements.
The radioactive chemicals decay and change into other chemical element overtime.
When a fossil is older it decays more.
Using Fossils
Paleontologists use fossils to determine how vertebrates changed over time.
The first vertebrates on Earth were fish.
Both mammals and birds descended from reptiles.
Pattern of Vertebrate Evolution
Jawless Fishes; fish appeared 530 million years ago
Cartilaginous Fishes
Bony Fishes
Amphibians; they appeared 380 million years ago and descended from fishes
Reptiles; they appeared 320 million years ago and desended from amphibians
Mammals; they appeared 220 million years ago and descended from reptiles
Birds; they appeared 150 million years ago and also descended from reptiles