The preserved remains of a once-living organism
The conversion of organic material into rock
A thick, slowly flowing liquid produced by plants that can harden into a solid.
Sum total of all fossils discovered
A term applied to a species that was once living but now is dead.
Fish that had bony plates covering their heads rather than the scales that cover the heads of fish today. Assumed to be extinct.
Creatures that live both in and out of water.
General Features of Fossil Record #1
Fossils are usually found in sedimentary rock. Since sedimentary rock is laid down by water, it follows that most fossils were laid down by water
General Features of Fossil Record #2
The vast majority of the fossil record is made up of hard-shelled creatures like clams. Most of the remaining fossils are of either water-dwelling creatures or insects. Only a tiny, tiny fraction of the fossils we find are of plants, reptiles, birds, and mammals.
General Features of Fossil Record #3
Many of the fossils we find are of organisms that are still alive today. Many of the fossils we find are of organisms that are now extinct.
General Features of Fossil Record #4
The fossils found in one layer of stratified rock can be considerable different from the fossils found in another later of stratified rock.